Definitions and Calculations

Question 1

Design Limit Load

Answer 1

The DLL is the maximum load that can be applied to the structure repeatedly during normal operations without inducing excessive fatigue and the pilot must never deliberately exceed this value.

Question 2

Design Ultimate Load

Answer 2

• The DUL is the minimum load the structure must be able to absorb in an emergency (heavier than normal landing or flight in exceptional gusty wind conditions) without collapsing. In order to keep weight to a minimum the aircraft’s structure ismanufactured from materials that are just capable of absorbing the DUL.
  -Structure subject to loads in excess of the DUL is likely to suffer some permanent damage and
  may even collapse altogether.
  -As a safe guard, the aviation authorities impose a factor of safety of 50% to the DLL to produce
  a Design Ultimate Load (DUL).

Question 3

CG is -

Answer 3

The centre of gravity (CG) is:
 the point that the total weight of the aircraft is said to act through
 the point of balance
 that part of the aircraft that follows the flight path
 the point that the aircraft manoeuvres about in the air
 the point that the three axes of the aircraft pass through.

Question 4

A CG moving towards the nose of the aircraft will progressively ___ the stability and, at the same time, progressively _____ the manoeuvrability. Similarly, a CG moving aft towards the tail of the aircraft will _____ the manoeuvrability and _____ the stability.

Answer 4

A CG moving towards the nose of the aircraft will progressively increase the stability and, at the same time, progressively reduce the manoeuvrability. Similarly, a CG moving aft towards the tail of the aircraft will increase the manoeuvrability and decrease the stability.

Question 5

Too much stability increases ___________ and the work load on the pilot trying to overcome them. Too much manoeuvrability makes the aircraft _______ and ____________.

Answer 5

Too much stability increases the flying control stick forces and the work load on the pilot trying to overcome them. Too much manoeuvrability makes the aircraft unstable and difficult to control.

Question 6

If the Ac CG outside the forward limit:

Answer 6

A CG outside the forward limit:
 Drag increases, consequently, fuel consumption, range and endurance decrease. In order to keep the nose of the aircraft from pitching downwards the tail plane must produce a balancing down load – a bit like a see-saw. The resulting elevator deflection increasesdrag, which in turn increase fuel consumption and reduces range and endurance.
 The longitudinal stability is increased, resulting in higher control column forces during manoeuvres and a corresponding increase in pilot fatigue.
 The increase in tail down force is equivalent to an increase in weight; consequently the stall speed will increase. An increase in stall speed has a significant effect on other performance aspects of the aircraft: take-off and landing speeds will increase, the available speed range will reduce and the safety margin between low and high speed buffet will narrow.
 The ability to pitch the nose up or down will decrease because of the increased stability.
 Take-off speeds V1, VR, VMU will increase. On the ground the aeroplane rotates about the main wheels and uses the elevators to raise the nose for take-off. The CG, being ahead of the main wheels, produces a down force that the elevators, together with the speed of the airflow passing over them, must overcome. The more forward the CG the greater the down force and, for a particular elevator deflection, the greater the speed of the airflow required. The aircraft must accelerate for longer to produce the air speed
required.

Question 7

A CG is outside the aft limit:

Answer 7

A CG is outside the aft limit:
 Longitudinal stability is reduced and, if the CG is too far aft, the aircraft will become very unstable (like a bucking bronco). Stick forces in pitch will be light, leading to the possibility of over stressing the aircraft by applying excessive ‘g’.
 Recovering from a spin may be more difficult as a flat spin is more likely to develop.
 Range and endurance will probably decrease due to the extra drag caused by the extreme manoeuvres.
 Glide angle may be more difficult to sustain because of the tendency for the aircraft to pitch up.

Question 8

What is the effect of CG movement on the various performance parameters of an ac

Answer 8

CG ON FWD LIMIT CG ON AFT LIMIT
STABILITY ↑ STABILITY ↓
STICK FORCES ↑ STICK FORCES ↓
MANOEUVRABILITY ↓ MANOEUVRABILITY ↑
DRAG ↑ DRAG ↓
VS (STALLING SPEED) ↑ VS ↓
VR (ROTATION SPEED) ↑ VR ↓
RANGE ↓ RANGE ↑
FUEL CONSUMPTION ↑ FUEL CONSUMPTION ↓
ABILITY TO ACHIEVE ABILITY TO ACHIEVE
1. CLIMB GRADIENT ↓ CLIMB GRADIENT ↑
2. GLIDE SLOPE ↓ GLIDE SLOPE ↑

Question 9

Datum

Answer 9

Datum
A point along the longitudinal axis (centre line) of the aeroplane (or it extension) designated by the manufacturer as the zero or reference point from which all balance arms begin.

Question 10

Balance Arm

Answer 10

Balance Arm
The distance from the aircraft’s Datum to the CG position or centroid of a body of mass.For the purposes of calculations, all balance arms ahead of (in front of) the datum are given a negative (-) prefix and those behind (aft of) the datum are given a positive (+) prefix.

Question 11

The Maximum Zero Fuel Mass

Answer 11

The maximum stress in the wing roots occurs when the wing fuel tanks are empty. To ensure that the wings don’t fold up permanently above the aircraft as the fuel is consumed a maximum zero fuel mass is imposed on the structure by the manufacturer.

Question 12

The operating mass of an aircraft is:
a. The dry operating mass plus the take-off fuel mass
b. The empty mass plus the take-off fuel mass
c. The empty mass plus crew, crew baggage and catering
d. The empty mass plus the trip fuel mass

Answer 12

A

Question 14

What effect has a centre of gravity close to the forward limit?
a. A better rate of climb capability
b. A reduction in the specific fuel consumption
c. A reduce rate of climb for a particular flight path
d. A decreased induced drag

Answer 14

C

Question 15

The DOM of an aeroplane is:
a. TOM minus Operating Mass
b. LM plus Trip Fuel
c. Useful Load minus Operating Mass
d. TOM minus Useful Load

Answer 15

D

Question 16

The Traffic Load of an aeroplane is:
a. TOM minus Operating Mass
b. LM plus Trip Fuel
c. Useful Load minus Operating Mass
d. TOM minus Useful Load.

Answer 16

A

Question 17

MINIMUM EQUIPMENT LIST

Answer 17

The MEL defines, amongst other things, the minimum level of serviceable usable equipment the aircraft must have prior to flight.

Question 18

Who’s responsibility is it that the ac has sufficient fuel ?

Answer 18

It is the commander of the aeroplane’s responsibility to ensure that there is sufficient fuel on board the aeroplane to safely complete the intended flight and to land with not less than a specified level of fuel remaining in the tanks – irrespective of delays and diversions.

Question 19

Give the calculation of Fuel while planning a flight

Answer 19

–2% of the tank left empty for venting
–START AND TAXI FUEL
Extended Twin Operations (ETOPs) for example
–TRIP FUEL -Sufficient for flight from airfield ‘a’ to airfield ‘b’ together with enough extra fuel to allow for bad weather on route and/or landing delays at airfield ‘b’.
–ALTERNATE FUEL (Usually 3% to 5% of the trip fuel). Sufficient to allow for a diversion from airfield ‘b’ to a planned diversion airfield ‘c’.
–FINAL RESERVE (Absolute emergency use only)
–CAPTAIN’S DISCRETION
Economic or other reasons

Question 20

Find the mass of 50 Imperial gallons of AVGAS with a specific gravity of 0.72.

Answer 20

Mass = 50 x 10 x 0.72 = 360 lb

Question 21

For 50 US gallons this would be:

Answer 21

Mass = 50 ÷ 1.2 x 10 x 0.72 = 300 lb

Question 22

Find the mass of 2250 litres of fuel with a density of 0.82.

Answer 22

Mass = 2250 x 0.82 = 1845 kg.

Question 23

You require 63,000 kg of fuel for your flight, the aircraft currently has 12,000 kg indicated on the gauges. How many US gallons of fuel do you request if the density is 0.81.

Answer 23

16660 US gallons

Question 24

The refueller has metered 4596 Imperial Gallons; your fuel gauges indicated 5,600 lbs
before refuelling. What should it indicate now? The fuel density is 0.79.

Answer 24

41908 lb

Question 25

If the mass of 6000 US gallons of fuel is 16780 kg, what is its S.G?

Answer 25

0.74

Question 26

The refuel bowser delivers 10,000 litres of fuel which is incorrectly entered on the aircraft load sheet as 10,000 kgs of fuel. Is the aircraft heavier or lighter than the take-off mass recorded on the Load Sheet and how would this effect the range? (Take the SG of the fuel as 0.75) a. Heavier and would decrease the range. b. Heavier and would increase the range c. Lighter and would decrease the range d. Lighter and would increase the range

Answer 26

Lighter by 2500 kg

Question 27

Define the useful load: a. traffic load plus dry operating mass b. traffic load plus usable fuel mass c. dry operating mass plus usable fuel load d. that part of the traffic load which generates revenue

Answer 27

A

Question 28

Determine the position of the CG as a percentage of the MAC given that the balance arm of the CG is 724 and the MAC balance arms are 517 to 1706. a. 14.2 % b. 15.3 % c. 16.3 % d. 17.4 %

Answer 28

D

Question 29

The distance from the datum to the CG is: a. the index b. the moment c. the balance arm d. the station

Answer 29

C

Question 30

Using CAP696, MRJT, fig 4.9. What is the balance arm, the maximum compartment load and the running load for the most aft compartment of the fwd cargo hold? a. 421.5 cm 3305 kg 13.12 kg per inch b. 1046.5 inches 711 kg 7.18 kg per kg c. 421.5 inches 2059 kg 13.12 kg per inch d. 1046.5 m 711 kg 7.18 kg per in

Answer 30

C

Question 31

Using CAP 696, fig 4.-12. Assuming the fuel index moves minus 5.7 from the ZFM index, what is the take-off CG as a percentage of the MAC? a. 20.1 % b. 19.1 % c. 23.0 % d. 18.2 %

Answer 31

A

Question 32

For a conventional light aeroplane with a tricycle undercarriage configuration, the higher the take-off mass: 1. Stick forces at rotation will increase 2. Range will decrease but endurance will increase 3. Gliding range will reduce 4. Stalling speed will increase a. all statements are correct b. Statement 3 only is correct c. Statements 1 and 4 only are correct d. Statement 4 only is correct

Answer 32

C

Question 33

Due to a mistake in the load sheet the aeroplane is 1000 kg heavier than you believe it to be. As a consequence: a. V1 will be later b. VMU will be later c. VR will be later d. V1, VMU, VR will all occur earlier

Answer 33

B

Question 34

If the aeroplane was neutrally stable this would suggest that: a. the CG is forward b. the CG is in mid range c. the CG is on the rear limit d. the CG is behind the rear limit

Answer 34

D

Question 35

Use CAP 696, MRJT as appropriate. Prior to departure a MRJT is loaded with maximum fuel of 20100 ltr at an SG of 0.78. Calculate the maximum allowable traffic load that can be carried given the following data: PLTOM 6,200 kg PLLM 54,200 kg DOM 34,930 kg Taxi fuel 250 kg Trip fuel 9,250 kg Contingency and holding fuel 850 kg Alternate fuel 700 kg a. 13,092 kg b. 12,442 kg c. 16,370 kg d. 16,842 kg

Answer 35

B

Question 36

The CG position is: a. set by the pilot b. set by the manufacturer c. able to exist within a range d. fixed

Answer 36

C

Question 37

If the maximum structural landing mass is exceeded: a. The aircraft will be unable to get airborne b. The undercarriage could collapse on landing c. No damage will occur providing the aircraft is within the regulated landing mass. d. No damage will occur providing the aircraft is within the performance limited landing mass.

Answer 37

B

Question 38

Use CAP 696, MRJT as appropriate. Prior to departure a MRJT is loaded with maximum fuel of 20100 ltr at an SG of 0.78. Calculate the maximum allowable traffic load that can be carried given the following data: PLTOM 6,200 kg PLLM 54,200 kg DOM 34,930 kg Taxi fuel 250 kg Trip fuel 9,250 kg Contingency and holding fuel 850 kg Alternate fuel 700 kg a. 13,092 kg b. 12,442 kg c. 16,370 kg d. 16,842 kg

Answer 38

B

Question 39

Which of the following would not affect the CG? a. Cabin crew members performing their normal duties. b. Fuel usage c. Stabilator trim setting d. Mass added or removed at the neutral point

Answer 39

C

Question 40

Using the data for the MRJT in CAP 696, what is the CG as a percentage of the MAC if the CG is 650 inches from the datum. a. 17.03% b. 18.14% c. 19.25% d. 20.36%

Answer 40

B

Question 41

The CG datum has to be along the longitudinal axis: a. between the nose and the tail. b. between the leading and trailing edge of the MAC. c. but does not have to be between the nose and the tail. d. at the fire

Answer 41

C

Question 42

The CG is : a. the point on the aircraft where the datum is located. b. the point on the aircraft at which gravity appears to act. c. the point on the aircraft from where the dihedral angle is measured. d. the point on the aircraft where the lift acts through.

Answer 42

B

Question 43

The aircraft basic mass and CG position is found on : a. the weighing schedule and the aeroplane must be re-weighed if equipment change causes a change in mass or balance b. On the loading manifest and is DOM – traffic load. c. On the loading manifest and is ZFM – useful load d. On the weighing schedule and is adjusted to take account of any mass changes.

Answer 43

A

Question 44

When determining the mass of fuel/oil and the value of the SG is not known, the value to use is: a. determined by the operator (and laid down in the aeroplane OPS Manual. A pilot simply has to look it up) b. set out in JAR OPS Section 1 c. determined by the aviation authority d. determined by the pilot

Answer 44

A

Question 45

In mass and balance terms, what is an index? a. A cut down version of a force b. A moment divided by a constant c. A moment divided by a mass d. A mass divided by a moment

Answer 45

B

Question 46

Standard masses for baggage can be used when: a. 9 seats or more b. 20 seats or more c. 30 seats or more d. less than 30 seats

Answer 46

B

Question 47

What is the zero fuel mass? a. MTOM minus fuel to destination minus fuel to alternative airfield. b. Maximum allowable mass of the aircraft with no usable fuel on board. c. Operating mass minus the fuel load. d. Actual loaded mass of the aircraft with no usable fuel on board.

Answer 47

D

Question 48

If an aeroplane comes into lands below its MSLM but above the PLLM for the arrival airfield: 1. Airframe structural damage will occur. 2. Tyre temperature limits could be exceeded. 3. It might not have sufficient runway length in which to stop safely. 4 A go-around might not be achievable. 5. Brake fade could occur.. a. All the answers are correct b. 3 and 4 only are correct c. 2, 3, 4 and 5 only are correct d. 1, 3, 4 and 5 only are correct

Answer 48

C

Question 49

A twin engine aeroplane of mass 2500 kg is in balanced level flight. The CG limits are 82 in to 95 in from the nose position of the aeroplane and the CG is approximately mid range. A passenger of mass 85 kg, moves from the front seat 85.5 inches aft of the nose to the rear seat157.6 inches from the nose. What is the new CG position approximately? a. 2.5 inches b. 87.5 inches c. 91 inches d. 92.5 inches

Answer 49

C

Question 50

What is the CG as a percentage of the MAC of the fully loaded aircraft? BEM 12,000 kg Arm 3 m CG 25% MAC MAC 2 m Item Balance arm Front seats 2.5 m Rear seats 3 m Fuel @ 0.74 410 Ltr Fuel arm 2.5 m Rear seats Empty Pilot 80 kg Front seat Pax 80 kg a. 16% b. 19% c. 21% d. 24%

Answer 50

D

Question 51

The maximum aircraft mass excluding all usable fuel is: a. fixed and listed in the aircraft’s Operations Manual b. variable and is set by the payload for the trip. c. fixed by the physical size of the fuselage and cargo holds. d. variable and depends on the actual fuel load for the trip.

Answer 51

A

Question 52

Just prior to take-off, a baggage handler put an extra box of significant mass into the hold without recording it in the LMC’s. What are the effects of this action? The aeroplane has a normal, tricycle undercarriage. 1. VMC will increase if the extra load is forward of the datum. 2. Stick forces in flight will decrease if the extra load is behind the datum. 3. Stick forces at VR will increase if the box is forward of the main wheels 4. VMU will occur later 5. The safe stopping distance will increase. a. 3, 4 and 5 only b. 2, 3 and 4 only c. 1 and 5 only d. all the above

Answer 52

A

Question 53

What is the maximum take-off mass given: MSTOM 43,000 kg MSLM 35,000 kg PLLM 33,000 kg MZFM 31,000 kg DOM 19,000 kg Total Fuel capacity 12,500 kg Maximum Trip Fuel 9,000 kg Contingency fuel 1000 kg Alternate fuel 500 kg Final reserve fuel 400 kg a. 43,000 kg b. 42,000 kg c. 41,000 kg d. 40,000 kg

Answer 53

B

Question 54

What is the maximum mass an aeroplane can be loaded to before it moves under its own power? a. Maximum Structural Ramp mass b. Maximum Structural take-off mass c. Maximum Regulated Ramp Mass d. Maximum Regulated Take-off mass

Answer 54

A

Question 55

The weight of an aircraft in all flight conditions acts: a. parallel to the CG b. at right angles to the aeroplane’s flight path c. always through the MAC d. vertically downwards

Answer 55

D

Question 56

With reference to MRJT Load and trim sheet (CAP696 Pg 31). If the DOM is 35000 kg and the CG is 14%, what is the D.O.I? a. 41.5 b. 33 c. 40 d. 30

Answer 56

C

Question 57

If the CG moves rearwards during flight: a. range will decrease b. range will increase c. stability will increase d. range will remain the same but stalling speed will decrease

Answer 57

B

Question 58

The CG of an aeroplane is situated at 115.8 arm and the mass is 4750 kg. A weight of 160 kg is moved from a hold situated at 80 arm to a hold at 120 arm. What would be the new CG arm?. a. 117.14 b. 118.33 c. 118.50 d. 120.01

Answer 58

A

Question 59

What is the effect of moving the CG from the front to the rear limit at constant altitude, CAS and temperature? a. Reduced optimum cruise range b. Reduced cruise range c. Increased cruise range d. Increased stall speed.

Answer 59

A

Question 60

The baggage compartment floor-loading limit is 650 kg/m2. What is the maximum mass of baggage that can be placed in the baggage compartment on a pallet of dimensions 0.8m by 0.8m. The pallet has a mass of 6 kg? a. 416 kg b. 1,015 kg c. 650 kg d. 410 kg

Answer 60

D

Question 61

An aeroplane of 110,000kg has its CG at 22.6m aft of the datum. The CG limits are 18m to 22m aft of the datum. How much mass must be removed from a hold 30m aft of the datum to bring the CG to its mid point? a. 26,800 kg b. 28,600 kg c. 86,200 kg d. 62,800 kg

Answer 61

B

Question 62

Where does the mass act through when the aircraft is stationary on the ground? a. The centre of gravity b. The main wheels c. It doesn’t act through anywhere. d. The aerodynamic centre

Answer 62

A

Question 63

If an aircraft is weighed prior to entry into service who is responsible for doing the re-weigh to prepare the plane for operations? a. The manufacturer. b. The operator c. The pilot d. The flight engineer.

Answer 63

B

Question 64

of 165000 kg (790 kg/m3). What is the specific gravity of the fuel and approximately how much more fuel could be taken up given that mass limits would not be exceeded? a. 0.73 46,053 gallons b. 0.81 3,940 gallons c. 0.72 46,000 gallons d. 0.79 3,946 gallons

Answer 64

D

Question 65

Define Balance Arm : a. BA = Mass / Moment b. BA = Moment / Mass c. BA = Mass / Distance d. BA = Moment / Distance

Answer 65

C

Question 66

You have been given 16500 litres of fuel at SG 0.78 but written down is 16500 kg. As a result you will experience : a. heavier stick forces at rotation and improved climb performance. b. heavier stick forces on rotation and distance to take-off increases. c. lighter stick forces on rotation and calculated V1 will be too high. d. lighter stick forces on rotation and V2 will be too low.

Answer 66

C