Tech Block 3

Question 1

1. When are reduced thrust take off’s used?

Answer 1

o There is a long runway available

o MTOW is low

Question 2

2. What are the 2 methods for reduced take offs?

Answer 2

Fixed derate (i.e 10%-20%) - For a given ambient condition, the thrust reduction achieved by selecting another certified takeoff rating that is lower than the maximum takeoff rating.

Assumed temperature - Based on a certified takeoff rating and ambient condition, the thrust reduction achieved by selecting the rated thrust for a temperature that is higher than the outside air temperature.

Question 3

3. Using an assumed temperature reduced thrust take off, what speed corrections are there?

Answer 3

o V1 is reduced to allow for slower acceleration but other speeds are the same for the actual TOW

Question 4

4. Factors that affect the engine thrust…

Answer 4

o Mass airflow increases…Thrust increases
o Temp increases…Thrust decreases
o Humidity increases…Thrust decreases
o Altitude increases..Pressure decreases…Thrust decreases

Question 5

5. What is ram effect?

Answer 5

As the aircraft increases speed the increase in density and mass flow through the engine results in an increase in thrust

Question 6

6. An increase in engine RPM results in…

Answer 6

o Higher mass air flow
o SFC decreases
o Higher temps
o Thrust output increases

Question 7

7. Two ways of measuring thrust are:

Answer 7

o	EPR (the ratio of inlet pressure and turbine exit pressure)
o	N1 (low pressure rotor speed)

Question 8

8. Engine bleed air has what effect:

Answer 8

o EPR decreases (engine pressure ratio)
o EGT increases
o Thrust decreases

Question 9

9. What is a compressor stall / surge?

Answer 9

A reverse flow of air through the engine caused by unstable air

Question 10

10. Reverse thrust is most efficient at…

Answer 10

o high speeds

Question 11

11. Documents required for international flight?

Answer 11

o	C of A
o	Aircraft F/Manual
o	Aircraft Registration
o	Flight Crew Licences
o	Valid Maint. Release
o	Load Sheet
o	Flight records
o	List of Crew & Passengers
o	Cargo bills of lading and manifests
o	List of disposable stores and spare parts
o	Route Guide

Question 12

12. What separation is provided by ATC between IFR & VFR traffic in Class “C” & “D” airspace?

Answer 12

o “C” IFR from IFR, VFR & SVFR
o “D” IFR from IFR, SVFR. IFR not from VFR, they are given traffic information.
o “E” IFR from IFR. IFR and VFR get traffic information. Shall not include control zones.

Question 13

13. When does the Runway Centreline Lights (RCLL) turn red?

Answer 13

o White to a point 914m from runway end.
o Alternate white &;a red between 914m & 300m.
o Red between 300m & the runway end.

Question 14

14. Definition of CAVOK?

Answer 14

o The term CAVOK is an acceptable contraction (meaning Ceiling and Visibility OK) for international use. It indicates that:
o No clouds exist below 5,000 feet or below the highest minimum sector altitude, whichever is greater, and no cumulonimbus are present.
o Visibility is 10 kilometres or more and,
o No precipitation, thunderstorms, sandstorm, dust storm, shallow fog, or low drifting dust, sand or snow is occurring.

Question 15

15. What are the classes of dangerous goods?

Answer 15

o Class 1 Explosives Every
o Class 2 Gasses Girl
o Class 3 Flammable Liquids Likes
o Class 4 Flammable Solids Sex
o Class 5 Oxidising Substances Orally
o Class 6 Poisonous / Infectious substances Plus
o Class 7 Radioactive substances Receiving
o Class 8 Corrosive agents Cum
o Class 9 Those that don’t fit above, eg magnetic materials

Question 16

16. If the static port blocks during the climb, what will the altimeter read?

Answer 16

o Whatever the reading was at the time of the blockage.

Question 17

17. What is the definition of Part 121?

Answer 17

o Pax configuration of more than 30 seats (excluding crew member seats)
o Payload capacity of more than 3410 Kg

Question 18

18. What is the purpose of Part 119?

Answer 18

o To prescribe the certification requirements for operators to perform Air Operations and the operating requirements for the continuation of this certification. Air Operations include Air Transport Operations (ATO) and Commercial Transport Operations (CTO).

Question 19

20. What is the purpose of Part 61?

Answer 19

o Prescribes the requirements to hold pilot licences and ratings; the prerequisites for those qualifications; and their privileges and limitations.

Question 20

21. What is the purpose of Part 91?

Answer 20

o Part 91 is an important rule as it forms the basis of general operating and flight rules for the New Zealand aviation environment. The requirements ensure that the safe operation of aircraft is possible with the minimum endangerment to persons and property.

Question 21

22. What is the critical engine on a propeller aircraft?

Answer 21

o On a propeller aircraft with conventionally rotating propellers, the critical engine is the left outboard engine, conversely with propellers rotating anti-clockwise, the outboard right engine would be critical. Counta/contra-rotating propellers do not have a critical engine.
o With conventionally rotating propellers, the down-going blade on each engine has a greater angle of attack producing more lift (thrust) thus offsetting the thrust line on each engine to the right. The right engine (on conventionally rotating propellers) has a greater arm to the C of G causing greater yaw, making the left engine critical.

Question 22

23. How does crosswind affect the critical engine?

Answer 22

o On a propeller driven aircraft, a crosswind from the opposite side to the critical engine will assist the situation because the yaw required to offset that which is produced by the failure of the critical engine will be assisted by the effect of the crosswind (weathercocking).
o The reverse situation will make matters worse. Crosswind from the same side as the critical engine will require even more demand from the rudder. The yaw produced by the failure of the critical engine will be compounded by the effect of the aircraft weathercocking.

Question 23

25. What is ETP and what is the formula?

Answer 23

o Equi time point – a point enroute where it will take the same time to go back as it will to carry on
o Dist to ETP = Total Distance x GS home
/ (G/S onward + G/S home)
o With a tailwind out ETP will move closer to departure.
o ETP moves into wind

Question 24

26. What is PNR and what is the formula?

Answer 24

Point of no return – a point which is based on fuel (endurance) at which you have the fuel to return if req’d
PNR Formula

Time to PNR (min.s) =

Endurance (min.s) x G/S home
G/S out + G/S home

Dist to PNR =

Endurance (hrs(decimals)) x G/S out x G/S home
G/S out + G/S home

Question 25

27. What is the formula for Equivalent Still Air Distance?

Answer 25

ESAD = Dist x TAS G/S The distance the aircraft has flown through the air.

Question 26

28. What is the formula for Gross fuel flow?

Answer 26

GFF = Fuel Flow (kg/hr) | G/S (nm/hr) = kg/gnm

Question 27

29. What is endurance?

Answer 27

o With endurance we need to fly as long as possible for a given amount of fuel. To use the least amount of fuel we need to use the least amount of thrust therefore we must fly at the speed for MIN DRAG. This is found at the bottom of the TOTAL DRAG vs IAS curve. o Since the thrust, and hence the consumption, should be the same at the same indicated speed at any height, it should not matter at what height we fly for endurance. Actually, when engine efficiency is taken into account, there are advantages in flying high (engine operating at design speeds and also the thermal efficiency, compressor efficiency, and the pressure ratio is better at higher altitudes). o Fuel Consumption with increase in Alt remains Constant, However in practise fuel consumption decreases with altitude. o In summary, for Endurance fly at speed for min drag as high as possible.

Question 28

30. Explain Range?

Answer 28

For maximum range we need to cover the maximum distance for a given amount of fuel. If we look at the TOTAL DRAG vs IAS curve once again then it can be seen that a very large increase in IAS can be achieved with a comparably small increase in total drag by drawing a line at a tangent to the curve. This is the speed for Maximum Range. At this speed it is the least amount of power for the a/c to achieve the highest TAS this also equates to min drag and max lift/drag ratio. The effect, on range, of an increase in weight requires in increase in speed for a constant angle of attack. Increase in headwind results increase in mach no. Aircraft will then be subjected to the headwind for a shorter period of time.

Question 29

31. If you were loading an airplane to obtain max range, would you load it with a forward or aft CoG?

Answer 29

o It would be best to load it with an aft C of G as this would require an upward force from the tailplane (or less of a downward force required from the tailplane) which acts in the same direction as lift and hence opposes some of the aircraft’s weight. Less lift from the mainplane means less drag therefore less thrust is required, less thrust means reduced fuel flow and hence more range can be obtained for the amount of fuel on board.

Question 30

32. Compare speed for Range Vs Endurance?

Answer 30

Speed for max endurance will always be lower than speed for max range. Max range is greatest distance covered for the amount of fuel used. SAR = TAS / GFC (gross fuel consumption) Tangent to the power req curve. Best range TAS INCREASES with altitude not IAS. Reduce weight to increase range. Max endurance is to remain in the air for the greatest amount of time for least amount of fuel. Min drag speed. Best at SL (less power) for piston engine. High for turbines. Increase in weight, reduces endurance.

Question 31

33. What sort of C of G changes occur on long flights?

Answer 31

o For a swept wing aircraft, as fuel is burnt off, the C of G moves forward. A consequence of a forward C of G is that the tailplane must then produce a compensating downwards balancing force which effectively increases the weight to be supported by the wing resulting in a higher stall speed at a constant weight. o An aft C of G is the best for fuel consumption as there is less downward push applied to the tailplane, effectively reducing weight, resulting in a lower stall speed. o A forward C of G is the most stable-stability of the aircraft is increased and the static and manoeuvre margins are large.

Question 32

34. How does cruise speed vary with fuel burn?

Answer 32

o Cruise speed reduces with gross weight due to fuel burn – less weight requires less lift resulting in less drag, therefore thrust can be reduced.

Question 33

35. What happens to SFC as altitude is gained?

Answer 33

o It decreases

Question 34

36. What effect happens if the aircraft is flown past the optimum flight level?

Answer 34

SFC increases as excessive drag results from an increased AoA which is required to create enough lift to support the aircraft. (The optimum altitude occurs at the optimum angle of attack for least thrust greatest TAS)

Question 35

37. Optimum altitude is a function of...

Answer 35

o SFC and TAS

Question 36

38. Does temperature affect optimum flight level?

Answer 36

o No as it has an equal effect on fuel flow and TAS

Question 37

39. Specific air range formula is...

Answer 37

``` o SAR = TAS o GFC (gross fuel comsumption) ```

Question 38

40. Long range cruise is...

Answer 38

o Flight at an optimum flight level, the airspeed is slightly higher than that at max range cruise as it is proportional to A/C weight. The range is reduced by 1 – 2 % of the max range cruise. For 'Max Range Cruise' cost index is zero, otherwise for a slightly higher fuel burn the long range cruise gives faster speed and better stability in average conditions.

Question 39

41. How does stall speed vary with C of G?

Answer 39

o A forward C of G increases stall speed. | o An aft C of G decreases stall speed

Question 40

42. Factors affecting the stall speed?

Answer 40

``` o Weight o Power o Flap o Loading o Ice/damage ```

Question 41

43. How does VMCA vary with C of G?

Answer 41

o As the C of G moves forward, the arm to the rudder increases, increasing its effectiveness. The opposite occurs as the C of G moves rearward. o Therefore: A forward C of G decreases Vmca, o and an aft C of G increases Vmca

Question 42

44. What is the function of an Inverter?

Answer 42

o Convert DC to AC

Question 43

45. What is the function of a Rectifier?

Answer 43

o Convert AC to DC

Question 44

46. What do CSD's do (Constant Speed Drives)..?

Answer 44

o A CSD runs off the accessory case and drives the AC generator at a constant RPM regardless of engine RPM. CSDs ensure that all generators are producing acceptable outputs of constant frequency, voltage, and phase, and allows each generator to be paralleled and to share the aircraft’s electrical load.

Question 45

47. What is RVSM?

Answer 45

Reduced Vertical Separation Minimum. In the late 1950s it was recognised that, as a result of the reduction in accuracy of the pressure-sensing capability of barometric altimeters with increasing altitude, there was a need above FL290 to increase the prescribed vertical separation of 1000ft. FL290 was chosen mainly as a result of the operational ceiling of aircraft at that time. Up to FL410 inclusive. Over time, air data computers (ADCs) combined with altimeters have become more accurate and autopilots more adept at maintaining a set level

Question 46

48. Name the 5 main modes of GPWS

Answer 46

o 1-Excessive rate of descent SINK RATE o 2-Excessive terrain closure TERRAIN PULL UP o 3-Excessive altitude loss after take off DON'T SINK o 4-Aircraft too low without gear or flap (shallow flight path) TOO LOW GEAR/TERRAIN/FLAP o 5-ILS deviation (1.3 dots below glide-slope) GLIDESLOPE o 6-Advisory callouts

Question 47

49. What are the inputs to GPWS?

Answer 47

``` o Radio altimeter o ILS receiver o Barometric pressure sensing o Flap & gear position o Airspeed ```

Question 48

50. What is the operating envelope of GPWS?

Answer 48

o 2450ft AGL to 30ft AGL (radio altimeter)