• NAVIGATION • RADIO AIDS • GENERAL • INSTRUMENTS • MISCELLANEOUS

ATPL VIVA GENERAL QUESTIONS

ATPL VIVA QUESTIONS: NAVIGATION

Great Circle: A circle on the surface of the earth whose centre and radius are those of the earth itself. It is circle of the surface of the sphere whose centre and diameter are that of earth. A plane of the great circle divides the earth in two equal parts. Great circle distance is the shortest distance along the arc of the great circle however this is not constant. Meridian and its anti-meridian make a great circle.

Rhumb Line: Rhumb line is a regularly curved line on the surface of the earth which cuts all the meridians on the earth at same angle. It is curve concaved to the nearer pole. Rhumb line track is constant between two positions but the distance is longer. Equator and meridian are the only two examples on the surface of the earth which are great circles as well as rhumb line. All latitudes are rhumb lines. Equator is the only latitude which is RL & GC.

Convergency: All the meridians on the surface of the earth from equator to the pole converge and they make angle at the pole. The angle of inclination between any two meridians is known as convergency. At equator meridians are parallels to each other, therefore convergency is zero. At the pole they make maximum angle, the angle is change of longitude. Zero convergency at equator and maximum at the pole. Therefore it varies as Sin latitude.

Conversion Angle: The angular difference between RL & GC bearing/track is conversion angle. CA = C/2. The relation between GC & RL will depend upon the hemisphere and bearing/direction.

Due earth’s convergency. Refer Oxford P.30

Variation can be checked from VIDP ground chart. Convergency is a relative term, question is incomplete.

Track Made Good is the actual path of the aircraft over the surface of a track as distinct from the intended track to be flown. It is often indicated by a double arrow on charts and maps.

Aircraft requires headwind component of at least 10 knots and has a crosswind limit is of 35 knots. The angle between the runway and wind direction is 600. Calculate maximum and minimum allowable wind speed.

Formulae to calculate wind is:

Headwind/Tailwind = Wind Velocity X Cos ɸ X Wind = Wind Velocity X Sin ɸ (ɸ is the angle between the runway direction and the wind)

Question states that aircraft requires atleast 10 knots of headwind component to takeoff, hence, 10 = WV COS 600 OR WV = 20 Kt. (Minimum) 35 = WV SIN 600 OR WV = 40 Kt. (Maximum) Runway crosswind value Thumb rule: Sin 10=.17 Sin 15=.3 Sin 30=.5 Sin 45=.7 Sin 60=.8 Sin 75=.9 Sin 90=10

True North: True north (Geodetic North) is the direction along the earth's surface towards the geographic North Pole. It is defined as the point in the northern hemisphere where the Earth's axis of rotation meets the Earth's surface.

Magnetic North: The direction indicated by a magnetic compass. Magnetic North moves slowly with a variable rate.

Grid North: This is the direction of a grid line which is parallel to the central meridian on the National Grid. Grid north is a navigational term referring to the direction northwards along the grid lines of a map projection. It is contrasted with true north (the direction of the North Pole) and magnetic north (the direction of the Magnetic North Pole). It is important to note that what people call the "Magnetic North on the Earth" is really the South pole of the earth's magnet, since the "North-seeking Pole" of a lodestone or small magnet (what we call "the North Pole") is attracted to it (and un-like poles attract).

Kilometer is 1/10000th of the average distance on the Earth between the Equator and either pole. Thus there are 10000 km between the equator and either Pole. Nautical Mile is that length of arc of a Great Circle which subtends an angle of one minute at the centre of curvature of the Earth’s surface. Because the earth is flattened at the Poles, the radius of curvature is increased and a greater arc is required to subtend an angle of one minute at the centre of Curvature, hence a nautical mile is longest at the pole at about 6108 feet and shortest at the equator and measures about 6046 ft. The average value taken is 6076 ft.

The circumference of the earth can be calculated by Departure = Change of longitude (Min) X Cos Latitude =360 X 60 X Cos 0 = 21600 NM

1 NM at Equator = 1NMat450 NS = 1 NM at 900 Pole = 6046 feet 6076feet 6108 feet

Refer Oxford P.108 & P179. Any ferromagnetic material (iron or steel) or electrical circuits in an aircraft may well have a magnetic field which affects the compass, hence the direction indicated by the compass needle is generally not Magnetic North. Non- ferromagnetic material, e.g. brass, aluminum, will not have a magnetic field and so will not affect the compass. Similarly significant changes in latitudes or maintenance may also introduce some deviation in the compass. The angle between Magnetic North and the direction indicated by a compass needle is called the angle of deviation. Deviation varies with heading so it has to be measured on a series of different headings. This is usually done by conducting a compass swing. Once deviation has been reduced as far as possible (by successive adjustment of screw on different headings) the residual deviation is then recorded on a compass deviation card, which is located in the aircraft.

http://www.geomag.nrcan.gc.ca/mag_fld/magdec-eng.php Declination is calculated using the current World Magnetic Model (WMM) or the International Geomagnetic Reference Field (IGRF) model. For aviation usage, it is given on Jeppesen charts for ready reference. Canadian topographic charts contain a diagram in the margin which gives the declination for the year in which the chart was published. Beneath the diagram is a statement informing the user about the annual change of declination. By multiplying the annual change by the number of years that have elapsed since the chart was published and adding the total change to the published declination value, the user obtains the present day declination.

RNAV Route to Initial approach fix RNAV5; IAF to Final approach FIX RNAV1; FAF to Landing RNAV 0.3; Missed approach again is RNAV1

The 1 in 60 rule states that if an aircraft has travelled sixty miles then an error in track of one mile is approximately a 10 error. However, precise figure of this the error is 0.960. Height = Angle X Range X 101 = 3 X 10 X 101 = 3030 ft. AGL.

It is that stage of flight from where aircraft takes same TIME either to reach destination or return back to base irrespective of ground speed. CP in zero wind: Only in nil wind conditions, CP lies midway. CP in tailwind conditions: In this condition, CP lies towards the base, i.e. distance to CP is less than half. CP in headwind conditions: In this condition, CP lies towards the destination i.e. distance to CP is more than half from base.

It is a fuel problem. PNR is that stage of the flight upto which aircraft can fly and return back to base within given endurance. Distance to PNR is maximum in NIL wind only. With the presence of winds (headwind or tailwind) distance to PNR reduces i.e. less than NIL wind.

Unable RVSM due Equipment / Due Turbulence.

Variation

While the MMEL is for an aircraft type family, the MEL is tailored to the operator's specific aircraft and operating environment and may be dependent upon the route structure, geographic location, and number of airports where spares and maintenance capability are available etc. The MMEL cannot address these individual variables or standard terms such as "as required by regulations". It is for these reasons that a MMEL cannot be approved for use as a MEL. MEL does not cover essential Airworthiness items such as Engine, Landing Gear, Flaps, Wings, Flight Control Surface etc. Categories for different classes are:

A: As per remarks B: 3 Days C: 10 Days D: 120 Days

MEL Purpose: The MEL is a joint operations and maintenance document prepared for or by an operator to: 1. Identify the minimum equipment and conditions for an aircraft to maintain the Certificate of Airworthiness in force and to meet the operating rules for the type of operation; 2. Define operational procedures necessary to maintain the required level of safety and to deal with inoperative equipment; and 3. Define maintenance procedures necessary to maintain the required level of safety and procedures necessary to secure any inoperative equipment.

The point at which LVPs should be implemented will vary from one aerodrome to another depending on local conditions and facilities available. The point at which LVPs are to be implemented must be clearly defined and should be related to a specific RVR or cloud ceiling measurement. Aerodromes may define higher values for RVR and ceiling than the ICAO standard depending on local circumstances In Delhi, whenever RVR (either TDZ, MID or END) drops down to below 800m and/or ceiling is below 200 feet, LVP will be enforced (Refer Jeppesen VIDP Chart 10-1P1). A take-off performed on a runway, where the RVR is less than 400 m, is termed as Low Visibility Take-off (LVTO).

Jeppesen P.377 The runway visual range shall be reported in meters throughout periods when either the visibility or the runway visual range is less than 1500m.

The touch-down zone RVR is always controlling. If reported and relevant, the mid-point and stop-end RVR are also controlling. (All Weather Operation Circular)

Standard communication failure procedures as per AIP Enroute 1.9. Also refer Jeppesen VIDP Chart 10-1-P13 (Arrival) & Chart 10-1-P18 (Departure)

A take-off alternate is required to be designated, whenever weather conditions at aerodrome of departure are lower than applicable landing AOM at that airport regardless of CAT II / III capability of the aircraft. Under such weather conditions, landing back, after departure, below CAT I conditions may be precluded due degradation of aircraft equipment / performance after take-off, or might not possible to land back at aerodrome of departure due performance or any other reasons.

A takeoff alternate needs to be designated; when RVR is less than 550m (regardless of fail-passive / fail-operational aircraft) OR when visibility / RVR at departure airfield is less than landing AOM at the same airfield OR when aircraft cannot land back at airfield of departure due performance / due any other reasons. As per CAR Section 8, Series ‘C’, Part I, on All Weather Operations (AWO), The take-off alternate aerodrome, for two-engine aeroplanes, in relation to the departure aerodrome, shall be: ➢ Located within one hour flight time at a one-engine inoperative cruise speed. ➢ Take-off alternate weather (actual and forecast) shall not be less than ILS CAT I minima

There are three types of scales: RF (Representative Fraction) Statement in Words A Graduated Scale (Printed on the map)

Jeppesen charts are based on which projection? What are the properties of Lamberts Conformal Charts (LCC)? Where else do you use it other than aviation?

The chart is specifically devised for use in middle latitudes. Two parallels which are 1/6 from the top and 1/6 from the bottom of the area to be projected are made standard parallels. Parallels are concentric arcs with apex arc in the centre, not of equidistance to each other. Meridians are straight lines converging towards the pole and are correctly spaced. Scale: Scale is correct at selected two standard parallels. In between the standard parallel it contracts (RF increases) and expands outside the standard parallel (RF decreases). For practical purposes it is considered a constant scale. On Lambert chart scale is least at poles. Convergency: Correct at parallel of origin. Towards the pole, it reduces and towards the equator it increases. Rhumb Line: Parallels and meridians are RLs elsewhere it is a curve concaved to the pole. Great Circle: GC is a straight line near the parallel or origin. Away from it, it is a very gentle curve, concaved to the parallel of origin. However, for practical purposes, it is taken as a straight line. Limitations: The chart size is chosen in such a manner that the scale error is less than 1%. An Artificial grid is required to be superimposed for plotting purposes.

Uses: It is used worldwide for air routes. Jeppesen charts are based on this projection only. On these charts, air route segments are GC segments and track mentioned in any segment and bearing measurement are correct and measured at the mid longitude or the segment. No convergency/conversion angle is required to plot VOR radio bearing.

Advantages over Mercator: Plotting of radio bearing is easier. Constant Scale can be used for measure the distances. GC tracks can be flown. It can be used in higher latitudes. Mariners most frequently use a Mercator projection. The Mercator is the most common projection used in maritime navigation, primarily because rhumb lines plot as straight lines. In the United States, the National Geodetic Survey uses Lambert Conformal Conic Projection to define the grid-coordinate systems used in several states (primarily those that are elongated west to east).

See Jeppesen Enroute Chart ME (H/L) 7, its states Parallel at 90 and 350.

Constant Angle Non-Precision Approaches CANPA advocates making a stabilized constant angle descent rather than a quick descent to the MDA followed by flying level at the MDA. CANPA offers a significant safety improvement for non-precision approaches under all conditions by providing a more stabilized flight path and reduced crew workload. The resulting stabilized approach from the FAF to the runway greatly simplifies the flight crew’s task on final approach and allows them more time to focus on acquiring the runway environment and conducting the landing. This in turn results in a higher success rate in landing off non-precision approaches, besides supporting the ICAO goal of having all approaches stabilized by 1000 feet AGL in IMC. There are three key elements to the CANPA brief: Computed Landing Altitude: Reference landing altitude should be 50 feet over the runway threshold (TDZE+50’)

Computed Touch Down Position: Used to determine the zero distance reference. From this point, the altitude checks at various distances from runway should be worked out, if not available from the approach chart. Computed Descent Rate: All approaches are to be flown at a computed constant descent rate to a Derived Decision Altitude (Height) DDA (H). A descent rate correction of not more than +/- 300 fpm may be made during the final approach. If more than +/-300 fpm correction is required on the final approach, the approach is considered unstabilized and a go-around should be initiated. (Momentary corrections exceeding +/-300 fpm do not require a go-around). At DDA (H), if the required visual reference is not established, an immediate missed approach must be initiated. Aircraft should climb on track to MAP, and then follow the published missed approach procedure.

How do you carry out a CANPA approach if FAF is not published? How is the FAF crossing height calculated?

Where a FAF is not defined in the chart, a pseudo FAF can be worked out on the inbound track, based on the initial approach/intermediate altitude. From this point, a rate of descent can be computed, ideally for a 3 degree glide path. A straight-in approach may be conducted if the pseudo FAF and the distance of the aircraft from touchdown can be determined using any of the following aids DME, FMS, GPS, ATC Radar.

If a go around is initiated at MDA while descending, the aircraft may go below the MDA during the missed approach maneuver, which is not allowed. To compensate for this, the operators must add a margin of at least 50 feet to the MDA and call it a Derived Decision Altitude (Height), so that executing a missed approach at the DDA (H) will not cause the aircraft to descend below the MDA.

Why is 50 feet not added to the DH in an ILS approach if the same if done for a CANPA approach to calculate the DDH?

As per the definition of DA, missed approach should be commenced upon reaching the DA incase visual reference is not available. No straight and level flight in such a case waiting for the visual cue. DA has been catered for this dip down. Also since it’s a precision approach, vertical guidance is available.

Decision Altitude (MSL) is mentioned on approach chart at which a decision must be made during an ILS approach or PAR instrument approach to either continue the approach or to proceed for missed approach.

Height referenced to the threshold elevation (AGL).

Decision altitude (DA) or decision height (DH) is a specified altitude or height in the precision approach or approach with vertical guidance at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Decision altitude (DA) is referenced to mean sea level and decision height (DH) is referenced to the threshold elevation. For convenience where both expressions are used they may be written in the form “decision altitude/height” and abbreviated “DA/H”. Where DH is referenced to threshold elevation, Circle to Approach Minima refers to airport elevation.

DAH means decision height taken on the radio altimeter.

The lowest altitude expressed in feet above MSL on which descent is authorized on final approach or during circle to land when doing non-precision approach i.e. without glide slope.

What are the domestic routes on Jeppesen enroute chart? And which of them are only one way

HVJW are domestic routes. HV are one way routes.

Maximum slope allowed is ±2%. It can be calculated by Difference of Elevation / Runway Length *100

Climb Gradient = ROC/GS x 0.98 (0.98 is derived from 60X100/6080) Climb Gradient = ROC/GS (Rule of Thumb)

If the average rate of climb from ground to FL410 is taken as 1400 ft/min at the ground speed of 300 kt, it comes out to be 4.6%.

An approximate value for the required feet/minute can be calculated by taking the groundspeed in knots and multiplying it by the required % gradient. So for example to get a 5% gradient at 100 knots ground speed requires 100 x 5 = 500 feet/minute ROC. This is based on the fact that 1 knot = approximately 100 feet/minute. 1 knot is actually 101.3 feet/per minute so a precise figure in the above example would be 506.5 feet/minute ROC. But 500 feet/minute is reasonable approximation.

Threshold Crossing Height. Height of the effective visual glide path over the threshold.

Minimum Eye Height over threshold. Lowest height over the threshold of the visual on glide path indication. MEHT or TCH is shown (when known) when less than 60’ for the upwind bar of a VASI (3 bar) system or less than 25’ for all other systems including PAPI.

ILS critical area: An area of defined dimensions about the localizer and glide path antennas where vehicles, including aircraft, are excluded during all ILS operations. The critical area is protected because the presence of vehicles and/or aircraft inside its boundaries will cause unacceptable disturbance to the ILS signal-in-space. ILS sensitive area: An area extending beyond the critical area where the parking and/or movement of vehicles, including aircraft, are controlled to prevent the possibility of unacceptable interference to the ILS signal during ILS operations. The sensitive area is protected to provide protection against interference caused by large moving objects outside the critical area but still normally within the airfield boundary.

AThe flight crew may apply Strategic Lateral Offset Procedure in remote continental airspace within Non-radar airspace when the aircraft is equipped with automatic offset tracking capability. Within non-radar airspace, the strategic lateral offset shall be established at a distance of 1 NM or 2 NM (Maximum 2NM) to the right of the centre line of the route relative to the direction of flight. In airspace where the use of lateral offsets has been authorized, pilots are not required to inform Air Traffic Control (ATC) that an offset is being applied. Special Procedures to mitigate Wake Turbulence Encounters and Distracting Aircraft System Alerts have been provided in the Oceanic Airspace of the Chennai, Kolkata and Mumbai FIR. Wake turbulence is likely to be experienced by the lower of two aircraft when it arrives approximately 15-30 nm behind an opposite direction aircraft which has crossed directly overhead on the same route.

A value equivalent to an RVR which is derived from the reported meteorological visibility, as converted in accordance with the specified requirements in the CAR. In cases where the RVR is not reported, a pilot may derive RVR/CMV by using a mathematical conversion depending upon the type of approach lighting and day/night conditions. CMV shall not be used for take-off, or for calculating any other required RVR minimum less than 800 m, or for visual approach / circling approach, or when reported RVR is available. CMV can only be used by Flight Crew in-flight. The RVR/CMV derived from the table below may be used by Flight Crew to commence or continue an approach to the applicable DA/MDA. Hi Approach & Lighting : Any other type of Lighting : No Lighting : Day 1.5; Night 2.0 Day 1.0; Night 1.5 Day 1.0; Night Not Applicable.

Commencement and Continuation of Approach (Approach Ban Policy) An instrument approach will not be commenced if the reported RVR/Visibility is below the applicable minimum. If, after commencing an instrument approach, the reported RVR/Visibility falls below the applicable minimum, the approach shall not be continued: ➢ Below 1000 ft above the aerodrome; or ➢ Into the final approach segment in the case where the DA/H or MDA/H is more than 1000 ft above the aerodrome; ➢ If, after passing 1000 ft above the aerodrome elevation, the reported RVR/visibility falls below the applicable minimum, the approach may be continued to DA/H or MDA/H.

The approach may be continued below DA/H or MDA/H and the landing may be completed provided that the required visual reference is established at the DA/H or MDA/H and is maintained.

In NDB chart for Runway 07 Chennai, visibility minima for Cat C and Cat D aircraft is published as 3400 and 5000 m respectively. If prevailing visibility is 3400m, can the approach be carried out for a Cat B category aircraft?

Since Cat B aircraft is a slower speed aircraft, minima will remain same or may even be lower than Cat C or Cat D.

Straight-In Approach: An approach with the final approach track aligned within 15 degrees for Category ‘C’ and ‘D’ aircraft and within 30 degrees for Category ‘A’ and ‘B’ aircraft of the extended centerline of the runway of intended runway. An instrument approach wherein final approach is begun without first having executed a procedure turn not necessarily completed with a straight-in landing or made to straight-in landing minimums. A straight-in approach simply means that you don’t fly a procedure turn or holding-in-lieu-of procedure turn. To fly a straight-in approach you must ensure that you are approaching the final approach fix from a direction that does not require a procedure turn, or you have been cleared for a straight in approach. A straight-in approach has nothing to do with the landing procedure. A straight-in approach can be made to a circle to land procedure. Straight-In Landing: A landing made on a runway aligned within 30 degrees of the final approach course following completion of an instrument approach. Straight-in landings are landings made to a runway aligned with the approach procedure. Any circle to land is not a straight-in landing.

PANS-OPS stands for Procedures for Air Navigation Services. It indicates that the state has specified that the approach procedure complies with ICAO Document 8168, Volume II, First or Second Edition. PANS-OPS3: Further indicates that holding speeds to be used are those specified in ICAO Document 8168, Volume II, Third Edition. PANS-OPS4: Further indicates that the acceleration segment criteria have been deleted, as formerly published in ICAO Document 8168, Volume II, First, Second or Third Editions.

MNPS stands for Minimum Navigation Performance Specification. Aircraft operating in the North Atlantic airspace are required to meet a minimum navigation performance specification (MNPS). The MNPS specification has intentionally been excluded from PBN because of its mandatory nature and because future MNPS implementations are not envisaged.

What are the different positions of the transponder switch in your aircraft and what does each one mean

OFF / STANDBY / TA / RA

If you have a glide slope failure what are the indications in your cockpit. How do you know if it is a Rx or Tx that has failed.

GS. No indication in the cockpit to find out whether Rx or Tx has failed.

This is an altitude derived by Jeppesen. The MORA provides known obstruction clearance 10NM either side of the route centerline including a 10NM radius beyond the radio fix reporting or mileage break defining the route segment. The Route MORA altitude provides reference point clearance within 10NM of the route centerline (regardless of the route width) and end fixes. Route MORA values clear all reference points by 1000ft in areas where the highest reference points are 5000ft MSL or lower. Route MORA values clear all reference points by 2000ft in areas where the highest reference points are 5001ft MSL or higher. When a Route MORA is shown along a route as “unknown” it is due to incomplete or insufficient information. MORA on Jeppesen Charts is shown as 1300a (Remember MORA A).

Grid Minimum Offroute Altitude (Grid MORA) is an altitude derived by Jeppesen or provided by State Authorities. The Grid MORA altitude provides terrain and man-made structure clearance within the section outlined by latitude and longitude lines. MORA does not assure navaid signal coverage or communication coverage. Grid MORA is for a particular quadrant on Jeppesen Chart; whereas, MORA is for an airway. Grid MORA values derived by Jeppesen clear all terrain and man-made structures by 1000 feet in areas where the highest elevations is 5000 feet MSL or lower and by 2000 feet in areas where the highest elevations is 5001 feet MSL or higher. When a Grid MORA is shown as “Unsurveyed” it is due to incomplete or insufficient information. Grid MORA values followed by a +/- denote doubtful accuracy, but are believed to provide sufficient reference point clearance. However, tolerance of this can always be cross-checked with the Route MORA or MOCA. Values below 10,000 ft will be depicted in Green Color; Values 10,000 ft and above will be depicted in Magenta Color (Related to the use of Oxygen). Earlier this benchmark used to be 14000 ft.

Minimum Enroute IFR Altitude (MEA) - The lowest published altitude between radio fixes that meets obstacle clearance requirements between those fixes and in many countries assures acceptable navigational signal coverage. The MEA applies to the entire width of the airway, segment, or route between the radio fixes defining the airway, segment, or route. An MEA will assure a clearance of at least 1000 feet over obstructions or terrain situated within a corridor of at least 5 NM at either side of the track. MEA on Jeppesen Charts is shown as 2500 or FL40 or with arrow when it is directional. GPS MEA is suffixed with G eg. 7500G.

Does MEA between two fixes guarantee two way communications when flying between the two fixes?

No. MEA assures acceptable navigational coverage and meets the obstacle clearance requirement. The minimum altitude at which reception will be adequate is MRA.

What is MOCA? What is MORA? State the difference between the two. Who derives MOCA and MORA?

Minimum Obstruction Clearance Altitude or MOCA is derived by Jeppesen. It is the lowest published altitude in effect between radio fixes on VOR airways, off airway routes, or route segments which meets obstacle clearance requirements for the entire route segment and assures acceptable navigational signal coverage only within 22NM of a VOR. MOCA on Jeppesen Charts is suffixed with T and shown as 4000T (Remember MOCA T). The MOCA is a true altitude above MSL. It does not take into account the means of measuring aircraft altitude. If a pressure altimeter is used for this purpose, the reading must be corrected for temperature and pressure datum. MORA does not provide for navaid signal coverage or communication coverage.

MRA is the lowest altitude which is mentioned on the Jeppesen Chart as MRA at which an intersection can be determined. OR MRA is the lowest altitude above sea level at which acceptable navigational signal coverage is received to determine the intersection.

MEA is higher than MOCA. MEA assures acceptable navigational coverage, whereas MOCA assures acceptable navigational coverage only within 22NM of a VOR.

The lowest altitude at certain fixes at which an aircraft must cross when proceeding in the direction of a higher Minimum Enroute IFR Altitude MEA.

The maximum authorized altitude (MAA) is the highest altitude at which the airway can be flown without receiving conflicting navigation signals from NAVAIDs operating on the same frequency.

Altitude depicted on instrument approach, SID or STAR charts and identified as the minimum safe altitude which provides a 1000 feet obstacle clearance within a 25 NM (or other value as stated) radius from the navigational facility upon which MSA is predicated. This altitude is for Emergency Use Only and does not necessarily guarantee NAVAID reception. When the MSA is divided into sectors, the altitudes in these sectors are referred to as minimum sector altitudes. The establishment of minimum sector altitude does not preclude an aircraft to approach from below, provided, its position has been fixed and it is approaching in conformity with an established instrument approach procedure or when being radar vectored.

Mountainous Area (ICAO) - An area of changing terrain profile where the changes of terrain elevation exceed 3000ft within a distance of 10NM.

The lowest altitude prescribed for holding pattern which assures navigation signal coverage, communication and meets the obstacle clearance requirement.

Summary: MORA (Jeppesen) 10nm either side of the entire Route Entire Route Suffix A eg. 1300a MEA (Jeppesen) 5nm Either Side of the Airway Between Two Radio Fixes 2500 or FL40 or with arrow when it is directional. GPS MEA is suffixed with G eg. 7500G. Acceptable Navigation Coverage MOCA (Jeppesen) Not written in Jeppesen could be same as MEA 5nm Between Two VOR Radio Fixes Suffixed with T e.g. 4000T Acceptable navigational signal coverage only within 22NM of a VOR *Only GRID MORA is provided by Jeppesen or State Authorities, rest all by Jeppesen Only

ATPL VIVA QUESTIONS:GENERAL

It’s a Ground-based, free-rotating, triangular-shaped wind direction indicator, generally placed near a runway, often lighted at major airports.

It was used in past to indicate the direction of runway in use in old time and can be illuminated in night. It still exists at airport like Jaipur (See Ground Chart, near wind-sock).

A : B : C : D : E : Less than 90 91-120 121-140 141-165 165-210 or above

Many airports also employ the use of Digital ATIS (or D-ATIS). D-ATIS is a text-based, digitally transmitted version of the ATIS audio broadcast. It is accessed via a data link service such as the Aircraft Communications Addressing and Reporting System (ACARS) and displayed on an electronic display in the aircraft.

These are depicted on Jeppesen charts as a full black arrow (down portion). The unshielded localizer transmits in both directions to give course guidance. Because the glide slope is not transmitted on the back side of the localizer, a back course approach is classified as a non-precision approach as it has no vertical guidance. The glideslope indications during a back course approach must always be ignored. This type of approach typically is found at smaller airports that do not have ILS approaches on both ends of the runway, where often the older localizer antennas are less directional. These transmit a signal from the back that is sufficient enough to be used in a back course approach. Newer localizer antennas are highly directional, and often cannot be used for a back course approach.

The RNP AR approach chart will identify outside air temperature limits applicable to operators using barometric vertical navigation (Baro-VNAV). Cold temperatures reduce the effective glide path angle while high temperatures increase the effective glide path angle without cockpit indication of the variation. Temperature affects the aircraft’s altitude indications and the effect is similar to high and low pressure changes, although not as significant. When temperature is higher than the International Standard Atmosphere (ISA), the aircraft will be higher than the indicated altitude. When temperature is lower than standard, the aircraft will be lower than indicated on the altimeter.

Operators using Baro-VNAV in an aircraft with an airworthiness approval for automatic temperature compensation, or in an aircraft using an alternate means for vertical guidance (e.g., Satellite-Based Augmentation Systems), may disregard the temperature limits. Also the lowest MSA given on SE sector is 5600 ft. If the pressure correction is taken by the QNH setting, temperature correction will still be required for a non-compensated altimeter i.e. True altitude = PA + (4 x ISA Dev x 1000's of feet) In this case, approaches are designed while keeping ISA conditions as standard, a temperature of 50C will mean a deviation of -100C. In such a case true altitude will be 5280 ft. vs indicated altitude of 5500 ft. At CABOT, minimum altitude is given as 5500 ft.

Refer Jeppesen Glossary P 7&11 of 118. It’s a “semi-precision” approach. An instrument approach based on a navigation system that is not required to meet the precision approach standards of ICAO Annex 10 but provides course and glide path deviation information. Baro-VNAV, LDA with glide path, LNAV/VNAV and LPV are examples of APV approaches. Since electronic vertical guidance is provided, the approach minimum altitude will be published as a decision altitude (DA). GBAS or Class 2, 3 and 4 TSO-C146 WAAS equipment for a GPS precision approach.

In India VOLMET Broadcasts are made by Mumbai and Kolkata Airports.

As per ICAO Doc 8168, max speed is 210 kt. below 6000 ft., however, as per Indian regulations, speed to maintain within 20nm of an aerodrome is 180 kt.

In India, ATS airspaces are designated as Class D, E, F and G and are categorized as per NOTAM G 0066/99. Delhi, Mumbai comes under Class D Airspace.

In Class D Airspace, traffic information is provided for all IFR & VFR, whereas, in Class E Airspace traffic information is provided where possible.

REMEMBER: SWAGAT Stall Windshear GPWS TCAS

As per CAR Section 8, Series O, Part III, a flight to be operated at altitudes at which the atmospheric pressure in personnel compartments will be less than 700 hPa shall not be commenced unless sufficient stored breathing oxygen is carried to supply: Note: 700hpa = 10000ft; 620hpa = 13000ft; 376hpa = 25000ft. a. All crew members and 10 per cent of the passengers for any period in excess of 30 minutes that the pressure in compartments occupied by them will be between 700 hPa and 620 hPa; and b. All crew members and passengers for any period that the atmospheric pressure in compartments occupied by them will be less than 620 hPa. c. In addition, when an aeroplane is operated at flight altitudes which the atmospheric pressure is less than 376 hPa, or which, if operated at flight altitudes at which the atmospheric pressure is more than 376 hPa and cannot descend safely within four minutes to a flight altitude at which the atmospheric pressure is equal to 620 hPa, there shall be no less than a 10 minutes supply for the occupants of the passengers compartment.

As per Jeppesen Middle East Page No. 279: Below FL150 and within 25 to 20 DME: 220 Knots Within 20 NM: 180 Knots Intercept Leg or 12 NM from touch down: 180-160 Knots 10 – 5 NM: 160-150 Knots

The ICAO Maximum holding speeds are defined as: Up to 14000 ft: 230kts 14000 ft to 20000 ft: 240kts 20000 ft to 34000 ft: 265kts Above 34000 ft: M0.83

ILS : VOR : NDB : 1 as in chart 11-1 3 as in chart 13-1 6 as in chart 16-1

If there are two airports in the same city like in Bangalore, then ILS will be 21-1, VOR will be 23-1 etc.

Longest TODA available is of Rwy 29 – 14534 ft. Longest LDA Available is of Rwy 10 – 11564 ft.

On a CAT D circling approach, what is the maximum distance from the airfield that you are allowed to go?

2.3 miles

At FL 270.

What is displaced threshold and what is the maximum displacement of the displaced threshold?

A displaced threshold is a runway threshold located at a point other than the physical beginning or end of the runway. The portion of the runway so displaced may be used for takeoff but not for landing. Landing aircraft may use the displaced area on the opposite end for roll out. In Delhi, Runway 29 has the longest permanent displaced threshold of 1460m. Rwy 28 Width is 148 feet or 45 meters.

HIALS — High intensity approach lights HIALS II — High intensity approach lights with CAT II Modifications HIRL — High intensity runway lights MIRL — Medium intensity runway lights RL — Low intensity runway lights PORT-RL — Portable electric runway lights FLARES — Flare pots or goosenecks MIALS — Medium intensity approach lights ALS — Low intensity approach lights LDIN — Sequenced flashing lead-in lights RAIL — Runway alignment indicator lights (Sequenced Flashing) REIL — Runway End Identifier Lights CL — Standard Centerline Light configuration White lights then alternating red & white lights between 3000' and 1000' from runway end and red lights for the last 1000'.

Runway edge lights are white. Runway threshold lights are unidirectional green in the direction of approach Taxiway edge lights are blue. Taxiway middle marker is continuous yellow line Runway centerline lights are white and will be alternating red and white from 3000 ft from far end becoming RED in the last 1000 ft. Rapid taxiway exit centerline lights are initially yellow and green and then all green.

A Stall Warning is an electronic or mechanical device that sounds an audible warning as the stall speed is approached. The simplest such device is a stall warning horn, which consists of either a pressure sensor or a movable metal tab that actuates a switch, and produces an audible warning in response. A Stick Shaker is a mechanical device that shakes the pilot's controls to warn of the onset of stall. A Stick Pusher is a mechanical device that prevents the pilot from stalling an aircraft. It pushes the elevator control forward as the stall is approached, causing a reduction in the angle of attack. In generic terms, a stick pusher is known as a stall identification device or stall identification system.

Angle of Attack Limiter Also referred to as an "alpha limiter" and angle of attack limiter is a computer that automatically prevents a pilot's computer input from raising the aircraft above its critical angle of attack. Some angle of attack limiters can be disabled, while others cannot.

According to the EU-OPS requirements, all non-precision approaches shall be flown using the continuous descent final approach (CDFA) technique with decision altitude (height), and the missed approach shall be executed when reaching the DA(H) in the event of an ILS approach or reaching an altitude of 1180 ft in case of a CDFA (LOC Only) approach. If due to some reason, like sudden increase in tailwind or low descent rate, aircraft is higher than 1180 ft and reaches the missed approach point (MAP), it should commence a missed approach incase runway is not insight.

Prohibited airspace.

Q Routes are based on RNAV5. Aircraft with high navigation performance are allowed to fly the RNP routes. With higher accuracy, more airplanes can be squeezed on an airway. The “Q” routes allow aircraft to aircraft longitudinal separation of 50NM, while A474 allowed for a 10 minute separation, which translates to around 75NM. Theoretically, up to 13 airplanes may now fly on Q1, at any point of time, as compared to 9 on A474.

What should be the weather deviation procedure while flying on the route Delhi to Kolkata in RVSM airspace and not in radar contact with Varansi or Kolkata.

Refer weather deviation procedures.

As DME is not given.

ATPL VIVA QUESTIONS: INSTRUMENTS

GPS, IRS/INS (If available), DME – DME, VOR - DME

GC

A GC track is divided into segments. At mid longitude of each segment mean of great circle and rhumb line are same. The segments are chosen in such a manner that the difference between great circle and rhumb line is minimum.

Instrument Errors Position / Pressure / Maneuver Induced Error Density Error Compressibility Error Blocked Pitot Blocked Static

Instrument Error Position / Pressure / Maneuver Induced Error Temperature Error Pressure Error / Barometric Error Temperature Error Lag Error Blocked Static Error Hysteresis Error: Expansion and contraction of the capsule for the same change of pressure should be same. If there is any deviation in the indicated reading, hysteresis error exists.

Instrument Error Position / Pressure / Maneuver Induced Error Lag Error Transonic Jump: A transonic shock wave passing over the static source will cause the VSI briefly to give a false indication.

ASI When Static is blocked it tends to under-read during climb and over-read during descent (Very dangerous situation). When Pitot is blocked it tends to increase in climb or decrease in descend steadily, and works like an altimeter i.e. gives an indication proportional to the altitude. When Pitot is leaked or fractured and drains are blocked, ASI tends to under indicate.

Altimeter If static is blocked altimeter continues to display the reading at which blockage occurred. And this will result in over indication if the aircraft descends and under indication if it climbs. If alternate source of static is used which is inside the unpressurized aircraft, altimeter tends to over read as static pressure inside the aircraft is lower than the ambient pressure due to aerodynamic suction.

VSI

It static is blocked, VSI indication will be too low while climbing or descending. It chock is blocked, VSI indication will be too high while climbing or descending. If VSI casing develops a leak, indication will be too high when climbing and too low when descending. If alternate source of static is used, VSI may show a momentary climb.

IAS ± PE = CAS – Compressibility error = EAS + Density Error = TAS

In NH, Undershoot North, Overshoot South Opposite results will be in SH. Turning errors are significant upto 35 degrees either side of those headings. ANDS

The angular difference between a freely suspended needle from its horizontal is known as Magnetic Dip. This angle varies at different points on the Earth's surface. The inclination value can be measured with an instrument known as a dip circle. The inclination is given by an angle that can assume values between -90° (up) to +90° (down). In the northern hemisphere, the field points downwards. It is straight down at the North Magnetic Pole and rotates upwards as the latitude decreases until it is horizontal (00) at the magnetic equator. It continues to rotate upwards until it is straight up at the South Magnetic Pole.

What are Gyros? What are their properties? Which instruments use Rigidity and which use Precession?

Gyro instruments work on the principle of gyroscopic inertia. Inside each of the gyro devices is a spinning wheel or disc. Its inertia, once the wheel has been accelerated, tends to keep the disc stable about its axis of rotation. Rigidity in Space: Rigidity is that force of gyro which does not allow any external force which tries to change of the direction of spin axis. Newton's First Law states "A body in motion tends to move in a constant speed and direction unless disturbed by some external force". The spinning rotor inside a gyro instrument maintains a constant attitude in space as long as no outside forces change its motion. This stability increases if the rotor has great mass and speed. Thus, the gyros in aircraft instruments are constructed of heavy materials and designed to spin rapidly.

The heading indicator and attitude indicator use gyros as an unchanging reference in space. Once the gyros are spinning, they stay in constant positions with respect to the horizon or direction. If the rotor axis represents the natural horizon or a direction such as magnetic north, it provides a stable reference for instrument flying. Precession: It is defined as when a force is applied to a running wheel, it does not act at the point of application and acts at a point 900 ahead in the direction of rotation. This turning movement, or precession, places the rotor in a new plane of rotation, parallel to the applied force. Artificial Horizon & Direction Gyro uses the property of Rigidity. Rate of turn indicator utilized the property of Precession.

Drift is maximum at the pole and zero at the equator (Same as convergency). Topple is maximum at the equator and zero at the pole.

AH uses Vertical Earth Gyro DG uses Tied Gyro TI uses Rate Gyro

While descending, temperature will start increasing, as a result LSS will increase and TAS will have to be increased in order to maintain the same ratio, hence, IAS and TAS both will increase.

What is the difference between Inertial Navigation System (INS) and Inertial Reference System (IRS)?

Refer KW P. 19 INS uses a stabilized platform with 2 accelerometers aligned north/south and east/west and 3 rate integrating gyros. The rate integrating gyros and accelerometer are mounted on the same platform. Schuler pendulum is used. The errors of INS fall into three categories, bounded, unbounded and inherent. In an INS, the acceleration are measured in a trihedron which is free from aircraft’s trihedron, pitch, roll and yaw axis (Remember INS is independent & free). INS provides aeroplane velocity and position and continuously measure and integrating its acceleration. This system relies on no external reference and is unaffected by weather and can operate day or night. All corrections associated with movement of the earth and transportation of the earth surface applied automatically. Acceleration integrated with respect to time gives velocity Velocity integrated with respect to time gives distance. Accelerometer is basically a pendulous device, when the aircraft accelerates, the pendulum moves due to inertia.

If the navigation function of an INS is inoperative and the control switch is set to ATT, the output data of the INS are Attitude and Heading. IRS uses 3 accelerometers and 3 laser gyros on a strapped down platform set at 900 to each other to form a trihedral to sense vertical, lateral and longitudinal accelerations. In a strapdown inertial system, the accelerations are measured in a trihedron which is fixed regarding aircraft’s trihedron (pitch, roll and yaw axis). An RLG as compared to a conventional gyroscope has a little or no “spin-up” time and it is insensitive to gravitational (g) forces. Laser (Light Amplification and Stimulated Emission of Radiation) gyros measure rotation by comparing two laser beams created and directed to rotate in opposite directions within a very narrow tunnel. High speed micro processors then achieve a stable platform mathematically rather than mechanically (as per the INS) - this results in greatly improved accuracy and reliability. Integration principles are used as per the older INS system. Calibration: Completed automatically by computer to enhance the overall accuracy of the system.

Schuler Tuning is again required to compensate for oscillation errors as the system is transported over the Earth (this in relation to pendulum theory which results in an 84.4 minute error cycle as described in the older INS. The Inertial Reference Unit (IRU) is the heart of the Inertial Reference System (IRS). It provides all required inertial reference outputs for the aircraft’s avionics. The primary sources of information for the IRU are its own internal sensors three laser gyros, and three inertial accelerometers. The only other inputs required are initial position, barometric altitude, and True Air Speed (TAS). Initial position is required because present position is calculated from the distance and direction travelled from the initial start position entered. Barometric altitude stabilizes the vertical navigation, and thereby stabilizes the vertical velocity and inertial altitude outputs. The TAS input allows the IRU to calculate wind speed and wind direction.

Activation: Almost no spin up time, one second activation for the rate sensor. Maneuvering: Insensitive to “G” attitude, rolling, pitching manoeuvres. Construction: Mechanically simple and highly reliable. Range: Wide dynamic range. Drift: Very small drift rates - greatest errors induced by the operator.

Bounded Errors: Are either fixed or oscillate about a mean. They do not get bigger with time or distance flown. e.g. a track error of one degree. This is a fixed error and does not increase with time. Unbounded Errors: Get larger with time or distance flown. The across track distance error would be an unbounded error as it is going to get bigger and bigger. The largest source of unbounded error is the imperfection of the gyroscopes leading to real wander. Inherent Errors: The irregular shape and composition of the earth, the movement of the earth through space and other factors provide further possible source of error.

Longitude Error.

Drift: The principle source of error with this form of device, as with the conventional gyro stabilized platform INS device, is associated with random drift in a conventional gyro. This is caused by laser system noise and is derived almost entirely from imperfections in the mirrors and their coatings. Accuracy: The accuracy of the laser system is directly influenced by the length of its optical path - the longer the path available the greater the accuracy with a small percentage increase in length leading to a substantial increase in accuracy. Lock in or Laser Lock: The most significant potential problem is lock-in, also known as laser lock, which occurs at very low rotation rates. At very low rotation rates the output frequency can drop to zero which causes the beams to synchronize that is, no longer indicate the rotation correctly and gives undesirable errors. This phenomenon is overcome by a vibration device known as a dither motor which breaks the lock-in. The motor is mounted in such a way that it vibrates the laser ring about its input axis through the lock in region, thereby unlocking the beams and enabling the optical sensor to detect the smaller movement of the fringe pattern. The motions caused by the dither motor are decoupled from the output of the ring laser gyro / rate sensor.

The Inertial System Display Unit (ISDU) provides pilot interface with the Inertial Reference Units (IRS). The ISDU allows entry of initialization data for the IRU's. The display of track angle, ground speed, present position, wind direction and speed, magnetic heading and system status is available.

Oxford P.436 Difficulties of flying near the poles are rapid change of true direction (due to convergency) and variation (due to proximity to the magnetic poles). Without an RNAV system, the solution is to ignore the compass and fly a gyro heading. Navigation in polar region can only be done through Grid Navigation technique. In grid navigation maps are overlaid with a grid of lines indicating gyro north to which gyroscope is aligned. While gyro steering is being employed, the magnetic element of the Gyro Magnetic Compass is disconnected.

The Flight Management System (FMS) provides lateral and vertical flight plan point-to- point navigation using multiple navigation sensors. The system generates lateral and vertical steering commands for use by the EFIS and FGS. The FMS Control Display Unit (CDU) provides flight deck management functions that include navigation sensor control, radio tuning, and Multifunction Display (MFD) control menus. The FMS consists of: ➢ Two Flight Management Computers (FMCs) ➢ Two Control Display Units (CDUs) ➢ Two Global Positioning Sensors (GPS); and ➢ One Data Base Unit (DBU). The Attitude Heading Reference System (AHRS), Air Data System (ADS), NAV receiver (VOR/ILS/ADF), and DME sensor supply data to the FMS. The FMS uses position data from the GPS, VOR, DME, and sensor data from the AHRS and ADS, along with the active flight plan and its own data base information to generate lateral and vertical flight plan based navigation solutions.

When you press TO-GA in your aircraft, what position update take place, IRS/GPS both?

GPS/AHRS

GPS & continuously verify position with raw data as well.

Use GPS and continuously verify position with raw data as well.

ESIS is Electronic Standby Instrument System. It is not a part of Proline 21 and is manufactured by a company called Meggit.

Hawker has a 3 Axis Autopilot (Roll, Pitch & Yaw) and is of dual channel.

Static Air Temperature, or SAT, is the temperature of the undisturbed air through which the aircraft is flying. Due to the kinetic energy of the speed of the aircraft, at higher speeds the measured temperature is higher than SAT as that kinetic energy gets converted into heat at the sensor. Total Air Temperature, or TAT, is the maximum air temperature that can be attained by 100% conversion of the kinetic energy of the flow.

A TAT measuring system measures the Total Air Temperature after Ram Rise on the forward facing parts of the aircraft, and the engines. A temperature measuring system qualifies as a TAT gauge if 99% or more of the Ram Temperature rise is recorded. A Ram Air Temperature (RAT) measuring system measures the Total Air Temperature after Ram Rise on the forward facing parts of the aircraft, and the engines, but due to system inefficiencies measures less that 99% of the temperature Rise.

AHRS (Attitude/Heading Reference System) The Attitude Heading Reference System (AHRS) generates three axis attitude and stabilized magnetic outputs for display on the AFDs and is used by the Flight Guidance System (FGS), Flight Management System, and hazard avoidance systems. The AHRS is a dual-independent system made up of: ➢ Two Attitude Heading Computers (AHC) ➢ Two External Compensation Units (ECU) ➢ Two Flux Detector Units (FDU) The AHC uses it’s own inertial sensors, inputs from the FDUs, and aircraft-specific information stored in the ECUs to calculate three axis attitude and heading information.

The FDU detects the horizontal component of the earth’s magnetic field. Other inputs to the AHC include alternate air data from the cross-side AHC and reference inputs from the IAPS (Integrated Avionics Processor System). Controls located on the flight deck are used to select Compass (magnetic) or Directional Gyro (free gyro) mode and to slew the compass heading. The AHC outputs provide attitude, magnetic heading, and system mode/status/fault data to the EFIS and other aircraft subsystems via the IAPS and the system bus structure. • Dual, independent systems with reversion (cross-connect) capability. • Automatic system initialization. • Controls to select Compass (magnetic) or DG (free gyro) mode operation. • Slew switch provided to adjust heading that shows on the AFDs.

It is not possible to obtain true heading in the aircraft, as Flux Detector Unit (FDU) supplies magnetic heading only.

The Rockwell Collins GPS-4000A Global Positioning System Sensor provides GPS-based navigation and enables GPS-based approaches for aircraft equipped with flight management systems. The GPS-4000A uses up to 12 GPS satellites. However, the system is capable to calculate navigation with a minimum of four satellites with acceptable geometry or three satellites plus calibrated barometric altitude. With additional satellites, the Receiver Autonomous Integrity Monitoring (RAIM) detects and isolates defective satellites while improving navigation accuracy. The unit’s predictive RAIM capability determines if the future satellite geometry at the destination airport will support planned arrival procedures.

Key Features & Benefits: ➢ Fully integrated with the Rockwell Collins Pro Line 4TM and Pro Line 21TM systems ➢ Provides terminal and en route navigation solutions ➢ Provides non precision approach navigation ➢ Supports primary means GPS navigation in oceanic/remote areas ➢ Supports RAIM, Predictive RAIM and FDE (Fault Detection & Exclusion) ➢ Supports on-board loading of application software ➢ 12-channel, TSO C129 (B1) compliant GPS receiver ➢ 2 MCU, ARINC 743A compliant ➢ DO-160D qualified ➢ Growth to SBAS to support GPS primary means navigation and non precision approaches with vertical guidance

The Radio Sensor System (RSS) provides the radios, controls, and displays used for voice communication, VOR/ILS navigation, distance measurement, ADF navigation, ATC transponder control, and TCAS Mode S communication. SYSTEM DESCRIPTION The RSS provides the radios and controls/displays used for voice communication (COM), navigation (NAV), and operation within the Air Traffic Control (ATC) environment. The RSS is a dual-independent system made up of pilot and copilot side control/display units, radios, and sensors. Baseline-equipped aircraft come standard with: ➢ Two VHF COM transceivers with 8.33 kHz channel spacing ➢ Two NAV receivers (one VOR/ILS/MKR/ADF and one VOR/ILS/MKR) ➢ Two Distance Measuring Equipment (DME) Transceivers ➢ Two ATC Mode-S Diversity Transponders with Flight ID. Optional equipment includes: ➢ An extended frequency VHF COM Transceiver with 8.33 kHz ➢ A third VHF COM transceiver with Data link ➢ A second ADF receiver (dual VOR/ILS/MKR/ADF) ➢ Single (standard) or dual HF COM Transceiver with HF antenna coupler

The display and control portion of the system consists of the two CDUs and a pilot side backup COM NAV Control (CTL). The CDUs provide integrated control of several combinations of aircraft communications and navigation subsystems. The integrated control includes the setting of radio frequencies, beacon codes, and operational modes. The CTL provides backup tuning for the pilot-side COM and NAV radios. The RSS provides digital radio data to the EFIS, navigation systems, and hazard avoidance systems via the IAPS and system bus structure. The COM1 and COM2 radio frequencies and ATC ident code are show on the PFDs. Each side RSS (pilot and copilot) is functionally isolated and acts as a stand-alone system. Each side RSS can control the cross- side radios/sensors in the event of a control or display failure.

KEY OPERATING FEATURES ➢ Integrated control of the COM/NAV/ATC radio suite. ➢ Manual tuning/control of radio suite from pilot or copilot station. ➢ FMS AUTO TUNE feature tunes the NAV/DME automatically for ➢ Multi-sensor NAV. ➢ ATC Mode-S Diversity Transponders for TCAS operation. ➢ Flight ID (Elementary Surveillance and Enhanced Surveillance) capable ATC Transponders. ➢ Backup tuning for pilot-side COM and NAV radios available from CTL-23 controller in event of dual CDU failure.

ATPL VIVA QUESTIONS: RADIO AIDS

The aircraft emergency frequency (also known as guard) is a frequency used on the aircraft radio band reserved for emergency communications for aircraft in distress. The frequencies are 121.5 MHz for civilian, also known as International Air Distress (IAD) or VHF Guard, and 243.0 MHz for military use, also known as Military Air Distress (MAD) or UHF Guard. Earlier Emergency Locator Transmitters used the guard frequencies to transmit, but an additional frequency of 406 Mhz is used by more modern ELTs.

A trend arrow up or down appears alongside the symbol when the intruder’s vertical rate is 500 feet per minute or greater.

Refer Oxford P.235 By reducing time delay at transponder.

Refer Oxford P.161 Microwave Horn Parabolic Reflector Flat Plate Antenna

What is the difference between a conventional CDI, HSI and why putting the right course on ILS is important despite the ILS instrument is tracking the difference between 90 & 150Hz lobes?

If you fly towards a VOR with a conventional CDI with the OBS correctly set (magnetic track to the VOR), indications will be correct. If you fly towards a VOR with a conventional CDI with the OBS set 180 degrees off (magnetic track from the VOR), indications will be reversed. Try the same with an HSI. In the latter case, the indications are still reversed. But the left and right indications are with respect to the direction of the course arrow. Because the course arrow is now pointing downwards, the entire readout system will be upside down. Thus the readout is reversed twice, and reads in the correct sense. For a localizer, the direction of the course arrow is irrelevant. You can fly the ILS with anything set on the OBS of a conventional CDI. However, if you set the course arrow of an HSI to 180 degrees off the localizer, the course arrow is now pointing downwards and the readout system is reversed -- just once now -- so the instrument reads in reverse. The autopilot, of course, doesn't care which direction the course arrow is pointing. So if you try to fly towards a VOR with the course arrow set 180 degrees off, the autopilot still sees reversed indications and fails to track the VOR. That was the rational behind the design of the HSI - by spinning the CDI (Course Deviation Indicator) needle around a compass rose, and slaving the compass rose to the aircraft heading, the HSI became a "command" instrument - for VORs it always operates in the command sense. All you have to do is look at it after setting up your radial to understand your current position with respect to that radial. As both VOR and ILS systems show your displacement from a line based on the phase difference between two radio signals, the same CDI has always been used for both systems. With an ILS signal, the "radial" is fixed, so the OBS isn't used by the system at all - it just detects the phase difference, and displays that on the needle. For the old fixed CDI display, it didn't matter what you put on the OBS when flying an ILS - as this bit isn't used at all by the ILS. Then the HSI came in, and the CDI turns around with the aircraft's heading. Now when using the ILS you need to set up the needle so that it points "up and down" with respect to the panel for it to operate in the command sense, and the only way to do that (as it rotates on a slaved compass card) is to set the OBS to the track you are going to be flying when you are established on the ILS (i.e. the inbound track).

For ILS the two lobes, the "left" and "right" lobes, are set up to display correctly for front course (the most common) approaches. If you are flying an approach to the reciprocal runway you are pointing the aircraft 1800 in the opposite direction for the approach, the "Left" and "Right" lobes are therefore 1800 out of sync - so you need to turn the CDI "upside down" to correct that. (Or flip the back course switch on the old fixed CDI indicator to reverse the sense.) HSI being a command instrument senses the deviation required from the correct course and aircraft’s actual position and gives command to FD. Hence the right course is required to be put during an ILS with modern systems.

As glideslope transmitter is placed along the runway to one side, the glideslope passes over the threshold at about 50 feet. This point over the threshold is called ‘ILS Reference Point’ the height as TCH (threshold crossing height).

VOR D: DME VOR H: High Altitude VOR T: Terminal VOR L: Low Altitude VOR STAR: Not available for 24 hrs.

Radios and Datalink as in LAAS.

➢ Site Error: Uneven terrain, physical obstacles and even over grown grass can affect VOR signals. VOR are ground monitor to an accuracy of ±10. ➢ Propagation Error: The signals having left the transmitter giving an accuracy of ±10 suffer further in accuracy as they travel forward and continue to effect throughout the passage of receiver. ➢ Airborne Equipment Error ➢ Aggregate Error: The combined effect of above three errors is known as aggregate error. ➢ Pilotage Error ➢ Beacon Alignment

AWAIT

If the difference between present and required QDM is less than 300, then the correction angle will be 3 times this difference and it will be added to the required QDM to obtain heading to intercept. Eg. From present QDM of 900 to intercept QDM of 700, the difference is 200. Three times of this will be 600 right of present QDM i.e. 900. Therefore heading to intercept will be 1300. If the difference between present and required QDM is more than 300, the corrective angle would be 900 left or right to the required QDM.

Quadrantal Error Terrain Night Effect / Sky Wave Interference Coastal Refraction Static Loop Alignment

Locator NDBs: Range is 10-25 NM Holding & Homing NDBs: Range is 50 NM Enroute NDBs: Range can be 200 NM over land and 500 NM over sea. Marine NDBs

It is a combination of slaved magnetic compass and ADF/radio compass. Dial is slaved to a remote magnetic compass, and needle is tuned to ADF.

Fixed Error: The indicator pointer moves in the steps of 5 feet which means 21⁄2 feet discrepancy may be present anytime. Mushing Error: Different height of Tx & Rx antenna with respect to terrain.

VOR and DME frequency can be paired together. The maximum distance between VOR and DME/TACAN ground installation if they are to have the same Morse code identifier is 100 feet in terminal area or 2000 feet outside a terminal area. If the distance is more than this and the frequency is paired, both VOR and DME will identify separately and one of the two will have a letter “Z” in the call sign. When a DME and VOR are collocated they transmit a total of 4 idents every 30 seconds. The first 3 of these idents are transmitted by the VOR and the 4th is transmitted by the DME and is of higher pitch. So in a period of 40 seconds, the DME ident will sound once.

Radar stands for Radio Detection and Ranging. All radars use pulse technique. Radar transmission is in pulses (not a continuous wave). Transmission is in burst of pulses.

a) VHF localizer equipment, associated monitor system, remote control and indicator equipment; b) UHF glide path equipment, associated monitor system, remote control and indicator equipment; c) VHF marker beacons, or a distance measuring equipment (DME) in together with associated monitor system and remote control and status indicator equipment. d) Approach Lighting System.

False Glideslope: Because of the emission pattern of the glideslope antenna, the 150 Hz signal will be received above the intended glideslope. This will give false, indeed reverse indications and will occur at an angle of twice the nominal angle. Aircraft must always approach the glideslope from below. Signal Reflection (Beam Bending): An apparent bending of the localizer beam may be caused by presence of aircraft, vehicles or other obstructions near the transmitter. Although the signal due to diffraction may go around obstructions, its modulation is affected, causing the apparent kinks. Separate holding points are designated for aircraft holding while precision approaches are taking place.

Wherever practicable, the localizer capture level of automatic flight control systems is to be set at or below 0.175 DDM in order to prevent false localizer captures.

No. The outer/middle marker is not a mandatory component for full ILS or the localizer. In fact at few newer airports in India for eg. VOHS, none of them is installed.

ILS can’t be carried out in this case. Alternate approach could be VOR / NDB Approach (time based) or a visual approach if weather conditions permits.

4096 Mode A & B: Used for identification of the aircraft. Mode C: For automatic height information Mode D: Still in experimental stage Mode S: This is used for communication surveillance in TCAS.

VOR works between 108.00 – 117.95 MHz. 108.00 - 111.95 MHz (Even) 112.00 - 117.95 MHz (All) Emission Pattern is A9W

VHF works in the range of 117.975 – 137 MHz. (Complete Range 30 – 300 MHz.) Wavelength is between 10 – 1 meters. VHF works on Frequency Modulation.

HF is single side band and works on Amplitude Modulation. Frequency Range 3 - 30 MHz Wavelength 100 - 10 m

VHF works on FM and HF works on AM. VHF primarily is dependent on line of sight. HF is used for long distance communication where line of sight is not possible. AM band is generally noisier; hence HF communications are not very clear as compared to VHF.

That’s because of the diurnal variation in the ionospheric density. If transmission is continued at night on a daytime frequency, a longer skip distance will result, leaving the receiver in the dead space. This is because at night, as we have seen, the electron density decreases; the signals travel higher in the ionosphere before refraction, and are refracted less. For these reasons, the working frequency is lowered at night. This lowering of the frequency adjusts the skip distance because the lower frequencies are refracted more. Attenuation is also less, despite the lower frequency, because the electron density is less.

The distance between the transmitter and the point on the surface where the first sky wave returns from Ionosphere is called the skip distance.

The area between the end of the surface wave and the first point of reception of the sky wave is called the dead space. (Ground Wave is surface wave + Space Wave)

Critical Angle is the minimum angle at which waves return to Earth. Prior to this, angles are known as Angle of Incidence.

A precision approach path indicator (PAPI) is a visual aid that provides guidance information to help a pilot acquire and maintain the correct approach (in the vertical plane) to an airport or an aerodrome. It is generally located beside the runway approximately 300 meters beyond the landing threshold of the runway. PAPI has single wing bar and consists of four light units on the side or both sides of runway adjacent to the touchdown point. Following are the indications: On Slope: Two outer lights of each wing bar are white and two inner lights (closer to the runway) are red (OWIR). Three Red : All Red : Three White : All White : Slightly Low 2.80 Lower than 2.50 Slightly High 3.20 Higher than 3.50 Precision Instrument Runway Markings: Threshold Marker to Touchdown Zone Marker Distance: 500 Feet Touchdown Zone Marker to Fix Distance Marker Distance: 500 Feet Total from Threshold to Fix Distance Marker: 1000 Feet

Two bar VASI has two pairs of wing bars extending outward of the runway usually at 500 feet and 1000 feet from the approach threshold. VASI approach slope only provides guaranteed obstacle clearance in an arc 100 left or right of the extended centerline out to a distance of 4NM from the runway threshold. Standard glide slope angle on VASI is 30. For Two Bar VASI: All Bars White: High on Approach Near Bar White and Far Bar Red: On Glide Slope All Red: Low on Slope

A Tri-colored VASI is a single light that appears amber above the glide slope, green on the glide slope and red below it (Amber, Green & Red). It has fallen out of widespread use, partly because pilots who are unfamiliar with them have been known to misinterpret the lights and 'correct' in the wrong direction. These errors are increased due to a major design shortcoming of the tri-colored VASI. While on approach, the colour amber (above slope) can be seen at a very thin angle of approach between green (on slope) and red (below slope) due to the mixing of red and green which gives an amber colour. Pilots not familiar with this may see the amber light and think they are above glide slope and then descend rather than make the proper correction and ascending back to glide slope. Despite this shortcoming, it is (reportedly) in widespread use in Eastern European countries, especially Russia and Ukraine.

A pulsating visual approach slope indicator (PVASI) is a single box system. The signal format is ➢ Solid white when established on the proper descent profile, ➢ Solid red when below the proper descent profile. ➢ An active pulsating white light is seen when well above or pulsating red when well below. Although PVASI is a single box system, its signal was evaluated by the U.S. Air Force and found to be much more accurate than VASI and equivalent to the four-box PAPI. These are obsolete now and are replaced by the PAPI as they were easily confused with other airport and surrounding lights.

Ionospheric Refraction Error (most significant error): UHF signals are not normally regarded as being refracted by the ionosphere, but such accuracy is required that even the very small amount of refraction they suffer increases the time taken for the signal to reach to the receiver as it bends through a shallow angle. When combined with the delay from other satellites, it is called the “Ionospheric Group Delay” and produces a total position error in order of 5 meters. Satellite Clock Error (Non-Synced errors upto 1.5 meters in range) Satellite Ephemeris Error: If satellite is not at its precise location (within ±0.5 meters) Geometric dilution of position error (GDOP): Satellites should be in different part of the sky and spheres must cut each other cleanly at an angle of 600. Multi path error: Occurs due to reflected signals which are generally weak in strength and come to receiver from unusual angles. Tropospheric Refraction Error: Refraction & attenuation also takes place in the troposphere. However, this is small and acceptable. Solar disturbances: Occurs due to solar wind and damaging radiations. Receiver measurement errors: Basically instrument error.

GNSS stands for Global Navigation Satellite System, and is the standard generic term for satellite navigation systems that provide autonomous geo-spatial positioning with global coverage. The term GPS is specific to the United States' GNSS system, the NAVSTAR Global Positioning System. As of 2008, the United States NAVSTAR Global Positioning System (GPS) is the only fully operational GNSS. Similarly, GLONASS is a Russian GNSS. India's next generation GNSS is known as GPS Aided Geo Augmented Navigation (GAGAN).

The Precision Runway Monitor (PRM) is a highly accurate air traffic surveillance system used by a specialist PRM Controller to maximize air traffic flow to parallel runways during periods of inclement weather. PRM allows qualified pilots to accept reductions in lateral separation standards during ILS approaches to parallel runways separated by less than 1,525 meters. Without PRM, ATC is required to apply a 2NM stagger separation between aircraft on adjacent ILS approaches. The specialized controller interfaces will alert ATC to any tendency an aircraft may have to deviate towards the adjacent centre line. In this event the PRM Controller will advise the pilot of the deviation. A “No Transgression Zone” (NTZ) with a width of 610 meters is established between the parallel approach paths to provide a suitable safety buffer between aircraft on adjacent ILS approaches. If an aircraft is observed to penetrate the NTZ, a “Breakout” procedure will be initiated immediately by the PRM Controller and both that aircraft and any conflicting aircraft on the adjacent approach will be turned away (Remember 2nm, 1525m, 610m). Pilot Requirements: To take advantage of the PRM system, pilots must familiarize themselves with the procedures to be used. An infringement of the NTZ does not allow any time for confusion or indecision on the part of the pilots or controllers. Breakout instructions require an immediate response. A thorough cockpit briefing between crew members well in advance of commencing the approach is an essential part of an ILS PRM approach. All flight crew members must be thoroughly familiar with the procedures to be followed in the event of a breakout. Separate approach charts have been issued specifically to be used for ILS PRM approaches.

ICAO Doc 8168 states that a single letter suffix, starting with the letter Z, following the radio navigation aid type shall be used if two or more procedures to the same runway cannot be distinguished by the radio navigation aid type only. The single letter suffix shall be used as follows: i. ii. iii. iv. v. vi. When two or more navigation aids of the same type are used to support different approaches to the same runway; When two or more missed approaches are associated with a common approach, each approach shall be identified by a single letter suffix; If different approach procedures using the same radio navigation type are provided for different aircraft categories; and If two or more arrivals are used to a common approach and are published on different charts, each approach shall be identified by a single letter suffix. If different DME is used for eg. VOR and ILS DME. If different DA are given. The one you use in this case will be dependent on what missed approach climb gradient you aircraft is capable of.

The Doppler Effect (or Doppler Shift) was discovered by Christian Doppler in 1842, is the change in frequency of a wave for an observer moving relative to its source. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

The relative changes in frequency can be explained as follows. When the source of the waves is moving toward the observer, each successive wave crest is emitted from a position closer to the observer than the previous wave. Therefore each wave takes slightly lesser time to reach the observer than the previous wave. Therefore the time between the arrivals of successive wave crests at the observer is reduced, causing an increase in the frequency. While they are travelling, the distance between successive wave fronts is reduced; so the waves "bunch together". Conversely, if the source of waves is moving away from the observer, each wave is emitted from a position farther from the observer than the previous wave, so the arrival time between successive waves is increased, reducing the frequency. The distance between successive wave fronts is increased, so the waves "spread out". For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source is relative to the medium in which the waves are transmitted. The total Doppler Effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in general relativity, only the relative difference in velocity between the observer and the source needs to be considered. Doppler Shift DS = 2 V Cos ɸ / Wavelength Where V is in Meters/Sec; DS and W/v is in Hz

EGPWS (Enhanced Ground Proximity Warning System) is actually the trade name that Honeywell uses for the "TAWS" system. TAWS stands for Terrain Awareness and Warning System. The main difference between GPWS and EGPWS is the introduction of a terrain data base and an interface to a source of position data, typically an FMS or an onboard GPS receiver. TAWS use these additional resources to produce FLTA (Forward Looking Terrain Avoidance) alerts and warnings, RTC (Reduced Terrain Clearance) alerts and warnings and PDA (Premature Descent along Final Approach Segment) alerts. The means of warning is aural and visual via the classic “Pull-Up” and “Glide-slope” annunciations, but the Class A variety of TAWS also must have a terrain display that provides the pilot with a visual “map” of the underlying terrain. The terrain display is color coded (red-amber-green) representing impact threats. The conventional GPWS could not detect flight into precipitous terrain (such as shear cliffs) effectively. It could obviously detect descent rates and closure to the ground, but could not predict precipitous rising terrain in the flight path ahead.

The Honeywell EGPWS system also offers obstacle alerting that warns of large towers and buildings that meet the warning criteria. This however is not a requirement of “TAWS”. Class A TAWS systems are required by aircraft operating in the "airline" category and some of the larger "commuter category" aircraft. Class B TAWS (which requires no radio altimeter interface or terrain display) is required by smaller (but not all) commercial aircraft.

A terrain conflict intruding into the caution ribbon activates EGPWS caution lights and the aural message. The caution alert is given typically 60 Second warning alert up to 8 nm look ahead of the terrain/obstacle conflict and is repeated every seven seconds as long as the conflict remains within the caution area. When the warning ribbon is intruded (typically 30 seconds prior to the terrain/obstacle conflict), EGPWS warning lights activate and the aural message “TERRAIN, TERRAIN, PULL UP” or “OBSTACLE, OBSTACLE, PULL UP” is enunciated with “PULL UP” repeating continuously while the conflict is within the warning area. (Remember EGPWS Alert at 60 seconds, 8nm every seven seconds, and warning at 30 seconds).

Windshear is defined as a sudden change of wind velocity and/or direction. Vertical windshear has variations of the wind component of 20 kt per 1000 ft to 30 kt per 1000 ft are typical values, but may reach up to 10 kt per 100 ft. Variations of horizontal wind component change in airspeed of 30 knots for light aircraft, and near 45 knots for airliners and may reach up to 100 kt per nautical mile.

A damaging downburst wind produced from a severe thunderstorm, that covers an area less than 4 kms. Microburst last for less than 5 minutes. Normally, microburst are the strongest downburst wind, and are capable of immense destruction. They should be thought of and treated no differently than tornadoes.

The windshear warning is based on the assessment of aircraft performance (flight parameters and accelerations). The windshear warning is generated whenever the energy level of the aircraft falls below a predetermined threshold. The windshear warning system associated to the Speed Reference System (SRS) mode of the flight guidance constitute the Reactive Windshear Systems (RWS), since both components react instantaneously to the current variations of aircraft parameters. To complement the reactive windshear system and provide an early warning of potential windshear activity, some weather radars feature the capability to detect windshear areas ahead of the aircraft. This equipment is referred to as a Predictive Windshear System (PWS). PWS provides typically a one-minute advance warning.

An RWS works on the principle of comparison between inertial and aerodynamic data through Speed Reference System (SRS) whereas a PWS works with the help of Doppler Weather Radar.

FANS (Future Area Navigation Systems) is a concept made by ICAO to use the Airspace more efficiently by developing the operational concepts for the future of Air Traffic Management. Operationally speaking, the biggest change provided by FANS is the way pilot and controllers communicate. In addition to the classical VHF and HF voice, and to the more recent satellite voice, digital CPDLC (Controller Pilot Data Link Communications) expands the set of communication means between pilots and controllers. FANS routes or air spaces are associated with a given RNP (Required Navigation Performance) value. This RNP is a statement on the navigation performance accuracy necessary for operation in this air space. CPDLC is a powerful tool to sustain data link communications between a pilot and the controller of the relevant flight region. It is particularly adapted to such areas where voice communications are difficult (e.g. HF voice over oceans or remote part of the world), and became very convenient to alleviate congested VHF of some dense continental airspaces when utilized for routine dialogue (e.g. frequency transfer).

ADS stands for Automatic Dependent Surveillance. Two kinds of ADS exist: 1) ADS-Broadcast (ADS-B) 2) ADS-Contract (ADS-C) These two kinds of ADS are quite different, as they do not rely on the same system. ADS- Contract is quite similar to CPDLC as it requires the establishment of a connection between the aircraft and the ATC centre. As per CPDLC, a notification should have been performed prior to ADS-C operations. Through this data link, the ADS-C application reports data requested in a contract established between the airborne system and the ATC ground system. Considering the range of ADS-C and ADS-B, they are expected to complement each other for a complete coverage during a transoceanic flight for instance when the aircraft is out of VHF coverage, ADS-C makes the link between the aircraft and the ATC centre. When in VHF coverage, ADS-B makes the link with any ATC centre or aircraft in the vicinity, equipped with an ADS-B receiver. ADS-B is a radically new technology that is redefining Air Traffic Management today. Already proven and certified as a viable low cost replacement for conventional radar, ADS-B allows pilots and air traffic controllers to “see” and control aircraft with more precision, and over a far larger percentage of the earth's surface, than has ever been possible before. ADS-B uses a combination of satellites, transmitters, and receivers to provide both flight crews and ground control personnel with very specific information about the location and speed of airplanes in the area.

They are differential GPS systems. The Wide Area Augmentation System (WAAS) is an air navigation aid developed by the FAA to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity, and availability during the en-route navigation using LORAN-C transmitters. WAAS uses a network of ground-based reference stations to measure small variations in the GPS satellites signals. Measurements from the reference stations are routed to master stations, which send the correction messages to geostationary WAAS satellites in a timely manner (every 5 seconds or better). Those satellites broadcast the correction messages back to Earth, where WAAS-enabled GPS receivers use the corrections while computing their positions to improve accuracy. ICAO calls this type of system a Satellite Based Augmentation System (SBAS). Europe and Asia are developing their own SBASs, the Indian GPS Aided Geo Augmented Navigation (GAGAN) and the European Geostationary Navigation Overlay Service (EGNOS). Chinese GPS system which is named Beidou was operational in December 2012 and has 16 operational satellites. It plans to provide global coverage from 2020.

The Local Area Augmentation System (LAAS) is an all-weather aircraft landing system based on real-time differential correction of the GPS signal. Local reference receivers located around the airport send data to a central location at the airport. This data is used to formulate a correction message, which is then transmitted to users via a VHF Data Link during the approach procedures. A receiver on an aircraft uses this information to correct GPS signals, which then provides a standard ILS-style display to use while flying a precision approach. ICAO calls this type of system a Ground Based Augmentation System (GBAS). This information is used to create an ILS-type display for aircraft approach and landing purposes.

LAAS mitigates GPS threats in the Local Area to a much greater accuracy than WAAS and therefore provides a higher level of service not attainable by WAAS. LAAS's VHF uplink signal is currently slated to share the frequency band from 108 MHz to 118 MHz with existing ILS localizer and VOR navigational aids. LAAS utilizes a Time Division Multiple Access (TDMA) Technology in servicing the entire airport with a single frequency allocation. With future replacement of ILS, LAAS will reduce the congested VHF NAV band. One of the primary benefits of LAAS is that a single installation at a major airport can be used for multiple precision approaches within the local area. This represents a significant cost savings in maintenance and upkeep of the existing ILS equipment. Another benefit is the potential for approaches that are not straight-in. Aircraft equipped with LAAS technology can utilize curved or complex approaches such that they could be flown on to avoid obstacles or to decrease noise levels in areas surrounding an airport. This technology shares similar characteristics with the older Microwave Landing System (MLS) Approaches, commonly seen in Europe. Both systems allow lower visibility requirements on complex approaches that traditional Wide Area Augmentation Systems (WAAS) and Instrument Landing Systems (ILS) could not allow. (Remember LAAS uses Time Division Multiple Access (TDMA) Technology).

GNSS Landing System is a Precision instrument approach.

An augmentation system in which the user receives augmentation information directly from a ground-based transmitter.

The GPS Aided Geo Augmented Navigation (GAGAN) is a planned implementation of a regional Satellite Based Augmentation System (SBAS) by the Indian government. It is a system to improve the accuracy of a GNSS receiver by providing reference signals. The project involves establishment of 15 Indian Reference Stations, 03 Indian Navigation Land Uplink Stations, 03 Indian Mission Control Centers and installation of all associated software and communication links. GAGAN is planned to get into operation by the year 2014. It will be able to help pilots to navigate in the Indian airspace by an accuracy of 3 meters. This will be helpful for landing aircraft in tough weather and terrain like Mangalore and Leh. The project is being implemented in three phases through 2008 by the Airport Authority of India with the help of the Indian Space Research Organization's (ISRO) technology and space support. US defense contractor Raytheon is the technology partner to build the system. The space component will become available after the GAGAN payload on the GSAT-8 communication satellite, which was launched recently, is switched on. This payload was also on the GSAT-4 satellite that was lost when the Geosynchronous Satellite Launch Vehicle (GSLV) failed during launch in April 2010.

To begin implementing a satellite-based augmentation system over the Indian airspace, Wide Area Augmentation System (WAAS) codes for L1 frequency and L5 frequency were obtained from the United States Air Force and U.S Department of Defense on November 2001 and March 2005. The system will use eight reference stations located in Delhi, Guwahati, Kolkata, Ahmedabad, Thiruvananthapuram, Bangalore, Jammu and Port Blair, and a Master Control Center at Bangalore.

ATPL VIVA QUESTIONS: MISCELLANEOUS

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Guwhati Approach Plates Patna Approach Plates Cochin Approach Plates – RNAV

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Seasons Equinox Convergency CA Lambert properties Mercator advantages MOCA MORA RVSM RVSM Outer marker symbol Schular tuning; first and second integration NDB Property NDB Principle INS/IRS Accelerometer IRS Fixed with aircraft? Enroute RNP 5 & 10 Precision RNAV + or – 1NM

1/60 Height = Angle X Range X 101 = 3 10 100 10 nm away from the airfield calculate aircraft height Height = 200 ft; Range 10000 ft Height = Angle X Range X 101 % = Height (NM) / Range * 100 ROD = angle X GS X 100/60 % = ROD/GS * 6080 Distance = Speed * Time

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