Aviation Knowledge Flashcards
(45 cards)
The only time you are ensured of getting magnetic winds from a weather report is:
From the airfield tower controller and ATIS. All other reports or forecasts (METARS or TAFs) and PIREPs use true winds for reporting.
How could you tell the difference between true north and magnetic north?
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.
What affects the speed of sound?
Why?
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.
If an aircraft moves much slower than the speed of sound, conditions are said to be:
Subsonic
If an aircraft moves near the speed of sound, conditions are said to be:
Transonic
For aircraft speeds greater than the speed of sound, conditions are said to be:
Supersonic
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:
Hypersonic, M > 5, and the high energy involved under these conditions has significant effects on the air itself.
Why may a roll to the left occur when you apply left rudder?
The right wing has more surface area into the wind creating more lift.
In a multi engine airplane during single engine operations which engine should be into the wind during landing?
Land the good engine into the wind. Helps counteract crosswind weather vaning.
What is a constant speed drive?
When are they used?
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.
What is a GCU and what does it do?
Generator Control Unit. Monitors voltage and frequencies and keeps the generator connected to the the bus.
Dehaveland Comet design flaw:
Metal fatigue
What is a compressor stall?
When is it likely to occur?
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.
What are some pros and cons of a Centrifugal flow compressor?
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.
Axial flow compressor:
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).
What keeps the generator spinning at a constant rate?
Constant Speed Drive
What could cause a hung start?
Insufficient airflow due to high altitude or hot day low-density air
Inefficient compression
Low starter rpms
Runway edge lights are what color?
How far are they spaced?
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.
Centerline lights are what color and how far apart?
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.
Touchdown zone length:
Touchdown zone markings spacing and length:
Touchdown zone elevation:
Touchdown zone lights length:
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.
Threshold markings are how long starting when?
150’ long starting at 20’ from the end of the runway.
If you see yellow chevrons (»»»»>) as part of airport markings what does this mean?
Used to show pavement areas aligned with the runway that are unusable for taxi, takeoff and landing.
Centerline markings are how long and spaced apart?
120’ long with 80’ gaps.
What does ADIZ stand for?
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.
