Aviation Knowledge

Question 1

The only time you are ensured of getting magnetic winds from a weather report is:

Answer 1

From the airfield tower controller and ATIS. All other reports or forecasts (METARS or TAFs) and PIREPs use true winds for reporting.

Question 2

How could you tell the difference between true north and magnetic north?

Answer 2

The magnetic declination at any particular place can be measured directly by reference to the celestial poles—the points in the heavens around which the stars appear to revolve, which mark the direction of true north and true south.

Question 3

What affects the speed of sound?

Why?

Answer 3

In our atmosphere the speed of sound is only affected by temperature. As the temperature increases the speed of sound increases. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly.

Question 4

If an aircraft moves much slower than the speed of sound, conditions are said to be:

Answer 4

Subsonic

Question 5

If an aircraft moves near the speed of sound, conditions are said to be:

Answer 5

Transonic

Question 6

For aircraft speeds greater than the speed of sound, conditions are said to be:

Answer 6

Supersonic

Question 7

For high supersonic speeds, 3 < M < 5, aerodynamic heating becomes very important. If the aircraft moves more than five times the speed of sound, conditions are said to be:

Answer 7

Hypersonic, M > 5, and the high energy involved under these conditions has significant effects on the air itself.

Question 8

Why may a roll to the left occur when you apply left rudder?

Answer 8

The right wing has more surface area into the wind creating more lift.

Question 9

In a multi engine airplane during single engine operations which engine should be into the wind during landing?

Answer 9

Land the good engine into the wind. Helps counteract crosswind weather vaning.

Question 10

What is a constant speed drive?

When are they used?

Answer 10

A constant speed drive (CSD) is a mechanical gearbox that takes an input shaft rotating at a wide range of speeds, delivering this power to an output shaft that rotates at a constant speed, despite the varying input. They are used to drive mechanisms, typically electrical generators, that require a constant input speed.

Question 11

What is a GCU and what does it do?

Answer 11

Generator Control Unit. Monitors voltage and frequencies and keeps the generator connected to the the bus.

Question 12

Dehaveland Comet design flaw:

Answer 12

Metal fatigue

Question 13

What is a compressor stall?

When is it likely to occur?

Answer 13

A compressor stall is a local disruption of the airflow in a gas turbine or turbocharger compressor. It is related to compressor surge which is a complete disruption of the flow through the compressor and compressor surge; or pressure surge, is a complete breakdown in compression resulting in a reversal of flow and the violent expulsion of previously compressed air out through the engine intake, due to the compressor’s inability to continue working against the already-compressed air behind it.
More likely to occur at low airspeed and high power.

Question 14

What are some pros and cons of a Centrifugal flow compressor?

Answer 14

Pros:
Centrifugal compressors are used throughout industry because they have fewer rubbing parts, are relatively energy efficient, and give higher airflow than a similarly sized reciprocating compressor.
They are often used in small gas turbine engines like APUs because the equivalent flow axial compressor will be less efficient. Further, they offer the advantages of simplicity of manufacturing and relatively low cost. This is due to requiring fewer stages to achieve the same pressure rise.

Cons:
They cannot achieve the high compression ratio of reciprocating compressors without multiple stages. There are few one-stage centrifugal compressors capable of pressure ratios over 10:1, due to stress considerations which severely limit the compressor’s safety, durability and life expectancy. They are impractical, compared to axial compressors, for use in large gas turbine engines propelling large aircraft, due to the resulting weight and stress, and to the frontal area presented by the diffuser.

Question 15

Axial flow compressor:

Answer 15

Axial flow compressors produce a continuous flow of compressed gas, and have the benefits of high efficiency and large mass flow rate, particularly in relation to their size and cross-section. They do, however, require several rows of airfoils to achieve a large pressure rise, making them complex and expensive relative to other designs (e.g. centrifugal compressors).

Question 16

What keeps the generator spinning at a constant rate?

Answer 16

Constant Speed Drive

Question 17

What could cause a hung start?

Answer 17

Insufficient airflow due to high altitude or hot day low-density air
Inefficient compression
Low starter rpms

Question 18

Runway edge lights are what color?

How far are they spaced?

Answer 18

White lights, except on instrument runways yellow replaces white on the last 2,000’ or half the runway length. 200’ apart not more than 10’ from the edge of the pavement. Green and red at the beginning and end of the runway.

Question 19

Centerline lights are what color and how far apart?

Answer 19

White until the last 3,000’ of the runway. White lights alternate with red for the next 2,000’ and are red the last 1,000’. They are spaced 50’ apart.

Question 20

Touchdown zone length:
Touchdown zone markings spacing and length:
Touchdown zone elevation:
Touchdown zone lights length:

Answer 20

Touchdown zone is defined as the first 3,000’ of runway beginning at the threshold.
Touchdown zone markings provide distance information in 500’ increments approximately 75’ long.
Touchdown zone elevation is the highest elevation in the first 3,000’ of the landing surface.
Touchdown zone lights start 100’ beyond the landing threshold and extend 3,000’ or first half of runway.

Question 21

Threshold markings are how long starting when?

Answer 21

150’ long starting at 20’ from the end of the runway.

Question 22

If you see yellow chevrons (»»»»>) as part of airport markings what does this mean?

Answer 22

Used to show pavement areas aligned with the runway that are unusable for taxi, takeoff and landing.

Question 23

Centerline markings are how long and spaced apart?

Answer 23

120’ long with 80’ gaps.

Question 24

What does ADIZ stand for?

Answer 24

Air Defense Identification Zone (ADIZ) is airspace over in which the identification, location, and control of civil aircraft is required in the interest of national security.

Question 25

QNE:
QNH:
QFE:

Answer 25

QNE = EASY, always 29.92
QNH = HARD, as in the ground is very hard...so set your altimeter properly
QFE = simply field elevation

Question 26

The terms Transition Altitude and Transition Level when do you change from QNH to QNE?

Answer 26

Going up through TA (“A” points up) and going down through Transition LeVel (“V” points down).

QNE = EASY, always 29.92
QNH = HARD, as in the ground is very hard...so set your altimeter properly
QFE = simply field elevation

Question 27

QFE reads what at the reference datum?

Answer 27

QFE is the barometric altimeter setting that causes an altimeter to read zero when at the reference datum of a particular airfield (in practice, the reference datum is either an airfield center or a runway threshold). In ISA temperature conditions the altimeter will read height above the airfield/runway threshold in the vicinity of the airfield. Skydivers use this method.

Question 28

Maximum Takeoff thrust (MTO):

Answer 28

This is the maximum thrust that the engine can deliver for 5 minutes in the take-off envelope of the aircraft. Peak thrust is usually achieved when the engine is static, however the most demanding condition for a modern turbofan engine is end-of-runway or lift-off conditions, typically at about 0.25Mn. This condition usually generates the highest stresses and temperatures in the engine, hence use of this rating is only permitted for up to 5 minutes of operation.

Question 29

Maximum Continuous thrust (MCT):

Answer 29

Outside the MTO flight envelope, the MCT rating defines the maximum thrust that can be demanded by the pilot from the engine. As such, it has particular significance with respect to engine failure in flight.

Question 30

When is an approach considered a circling approach?
How much obstacle clearance does it provide?
What is the radius (NM) of each approach category (A-E)?

Answer 30

When an approach requires more than 30° turn.
It only provides 300' of obstacle clearance.
A: 1.3
B: 1.5
C: 1.7
D: 2.3
E: 4.5
(1.Odd number 3, 5, 7 then 2.Odd 3, 5)

Question 31

Where does the fire bottle spray the agent in the event of an engine fire?

Answer 31

In the engine bay or compartment, not in the combustion section.

Question 32

What converts AC to DC power?

Answer 32

Transformer rectifier

Question 33

How are batteries effected when connected in series and parallel?

Answer 33

Series: Adds voltage but not amperage
Parallel: Adds amperage but not voltage
(Bigger bat when in the world series, amped to be parallel with your friend)

Question 34

What are the meanings of the colored disks on a fire extinguisher?

Answer 34

Red disk ruptured or missing: Thermal discharge

Yellow disk ruptured: Intentional discharge

Question 35

When do you need to slow down for holding?

Answer 35

3 minutes prior to fix.

MHA - 6000’ MSL: 200 KIAS
6001’ - 14,000’ MSL: 230 KIAS (210 where published)
14,000’ MSL + : 265 KIAS

Question 36

What are the holding speeds and altitudes?

Answer 36

MHA - 6000’ MSL: 200 KIAS
6001’ - 14,000’ MSL: 230 KIAS (210 where published)
14,000’ MSL + : 265 KIAS

Question 37

What are the leg lengths in a holding pattern?

Answer 37

At or below 14,000’ MSL: 1 minute inbound

Above 14,000’ MSL: 1.5 minutes inbound

Question 38

What altitude would you use 1.5 minutes inbound for holding?

Answer 38

Above 14,000’ MSL

Question 39

What factors should you consider when avoiding hydroplaning?

Answer 39

Touchdown speed should be as slow as safely possible.
After the nosewheel is lowered to the runway, moderate braking should be applied.
If hydroplaning is suspected, the nose should be raised and aerodynamic drag used to decelerate to a point where the brakes do become effective.
Proper braking technique is essential. The brakes should be applied firmly until reaching a point just short of a skid. At the first sign of a skid, the pilot should release brake pressure and allow the wheels to spin up.

Remember: In a crosswind, if hydroplaning should occur, the crosswind will cause the airplane to simultaneously weathervane into the wind as well as slide downwind.

Question 40

Describe dynamic hydroplaning:

Answer 40

Dynamic hydroplaning is a relatively high-speed phenomenon that occurs when there is a film of water on the runway that is at least one-tenth inch deep.
As the speed of the airplane and the depth of the water increase, the water layer builds up an increasing resistance to displacement, resulting in the formation of a wedge of water beneath the tire.
When the water pressure equals the weight of the airplane, the tire is lifted off the runway surface and stops rotating. Directional control and braking is lost. Dynamic hydroplaning is often affected by tire inflation pressure.

Question 41

Describe reverted rubber hydroplaning:

Answer 41

Reverted rubber (steam) hydroplaning occurs during heavy braking that results in a prolonged locked-wheel skid. Only a thin film of water on the runway is required to facilitate this type of hydroplaning.
The tire skidding generates enough heat to cause the rubber in contact with the runway to revert to its original uncured state (think ‘melting’). The reverted rubber acts as a seal between the tire and the runway, and delays water exit from the tire footprint area. The water heats and is converted to steam which supports the tire off the runway. Reverted rubber hydroplaning frequently follows dynamic hydroplaning, during which time the pilot may have the brakes locked in an attempt to slow the airplane. Eventually the airplane slows enough to where the tires make contact with the runway surface and the airplane begins to skid.
The remedy for this type of hydroplane is for the pilot to release the brakes and allow the wheels to spin up and apply moderate braking.
It can persist to very slow ground speed (20 knots or less).

Question 42

Describe viscous hydroplaning:

Answer 42

Viscous hydroplaning is due to the viscous properties of water. A thin film of fluid no more than one thousandth of an inch in depth is all that is needed.
The tire cannot penetrate the fluid and the tire rolls on top of the film. This can occur at a much lower speed than dynamic hydroplane, but requires a smooth or smooth acting surface such as asphalt or a touchdown area coated with the accumulated rubber of past landings. Such a surface can have the same friction coefficient as wet ice.
And although this kind of hydroplaning may seem as ‘vicious’ as a mad dog when you encounter it, please remember it is pronounced like “vis-kus”.

Question 43

After going missed approach at what airspeed would you climb out is diverting?

Answer 43

L/D Max or Max range

Question 44

Compare flying an approach to a narrower / wider than normal runway:

Answer 44

Narrower runway = feel higher so may fly a lower approach

Wider runway = feel lower so may fly a higher approach

Question 45

How far above and around should you avoid a thunderstorm?

Answer 45

20 NM around on the upwind side. 1,000’ above for every 10 kts of wind at that altitude.