Technical Interview 12 Flashcards
How is the start generated in the Seneca?
Note: make sure to be able to answer this question for your own previous aircraft type
Battery power to the starter motors.
If the yaw damper fails and the aircraft experiences Dutch roll, how can the pilot stabilize the aircraft?
Apply opposite aileron to the direction of the roll.
Tell me about the last aircraft you flew in.
Note: this question was asked to a candidate with previous Seneca experience, make sure to be able to answer this question for your previous aircraft type.
Example answer for a candidate with previous Seneca experience:
Weights:
Max all up weight – take off 4570lbs
Max all up weight – landing 4340lbs
Empty weight - 2830lbs
Usefull load - 1740lbs
Speeds:
Clean stall 66kts with flaps 60kts
Vyse 89kts
Cruise 140kts gear raising 107kts – lowering 129kts.
Vne 195
The 6 cyclinder teledyne continental turbo- charged, fuel injected engines provide 200 hp at 2575.
Left engine rotated clockwise and right anti clockwise.
No critical engine, RayGay turbo’s 42” MAP, 40” limit at lower levels, cowl flaps provide cooling and has 3 positions, open mid and closed.
Avgas 100/130
Props 2 or 3 blade, constant speed, hydraulically actuated, fully feathering.
Oil keeps props at fine pitch, gas and air keep the rpm towards feather. Takes 6 seconds to feather and must happen before locks engage at 800 rpm.
Limit load factor 3.8G
Fuel 2 x 54 (64US) gallons tanks 8 quarts oil max 6 Min
Retractable gear – hydraulic pumps – electrically driven. 6-7 seconds transit
Nose gear has 27 degrees castor.
Main wheels 55psi, nose wheel 31psi
Cable operated controls, all moving stabilator with anti servo tab which acts as a trim.
Frise ailerons and differential ailerons, up more than down.
Manual flaps, 3 settings, 10, 25, 40 degrees.
4.5” – 5.2” hg suction – AH, DI.
Heated lift deflectors and stall warners, anti ice.
If turboprops are more efficient aircraft, why do they not climb that high?
Jet engines are designed to achieve their best specific fuel consumption at high rpm, which can only be achieved at high altitudes where the air density is low.
Thrust produced will be low enough to equal the required cruising thrust. Also high altitude gives the best operating conditions for the airframe i.e. minimum drag during the cruise.
Turboprops need relatively dense air for the propellers to work efficiently and at high altitude the density would be too low.
Is the landing gear in the Seneca electrically or hydraulically operated?
Note: make sure to be able to answer this question for your own previous aircraft type
Hydraulically driven by 2 electric pumps with a 7 second transit.
What are the advantages of fuel injection vs carb?
The following are advantages of using fuel injection:
- Reduction in evaporative icing
- Better fuel flow
- Faster throttle response
- Precise control of mixture
- Better fuel distribution
- Easier cold weather starts
The following are disadvantages of using fuel injection:
- Difficulty in starting a hot engine
- Vapor locks during ground operations on hot days
- Problems associated with restarting an engine that quits because of fuel starvation
Is carburettor heat an electrical system?
No, you mechanically change a valve that changes the air intake to air that runs past the exhaust manifold and is therefore heated.
When using carburettor heating a warm air is routed into the engine intake manifold instead of the cold outside air - this of course reduces the density of the air and its mass for a given volume - basically the same effect as increasing altitude → mixture will get richer (too much fuel mass for the air mass) and the engine performance decreases due to the lower air density.
How do the pneumatic de-icing devices on the Seneca work?
Note: make sure to be able to answer this question for your own previous aircraft type
Boots on the leading edges inflate (6 seconds) to break the ice dissipating it into the airflow.
Powered by the gyro pressure system.
What is the advantage of a variable pitch propeller? Why not have a fixed propeller?
A variable pitch propeller provides an optimum angle of attack for the propeller blades for a longer range which reduces fuel usage, fixed pitch propellers only have a certain rpm.
Why don’t you use carb heat on the ground for long periods?
Use of the heat control on the ground should be kept to a minimum as the intake air is not filtered when carburettor heat is selected “hot” and consequently dust and dirt may be fed into the induction system causing additional wear on pistons and cylinders.
What will happen if the primer of your engine/fuel system kept operating?
The engine will flood with fuel.
Where the brakes and gear hydraulically operated on the Seneca?
Note: make sure to be able to answer this question for your own previous aircraft type
Only hydraulic gear.
Where does the wing stall first on a DA42?
Note: make sure to be able to answer this question for your own previous aircraft type
At the wing root.
What is induced drag?
Induced drag is a by-product of lift and exists only if lift exists.
What is profile drag?
Profile drag, also known as pressure drag or form drag, is the drag caused by the separation of the boundary layer from a surface and the wake created by that separation.
It is primarily dependent upon the shape of the object and increases directly with speed as the faster an aircraft moves the more air molecules collide with it.
