Study Questions Flashcards
How are the control surfaces mechanically operated?
Through a manual (unassisted) linkage ( standard bellcrank, push/pull rod, cable, pulley)
What type of trim tabs do the ailerons incorporate and where are the tabs located?
Trailing edge of left aileron. Electrically operated by an actuator consisting of a 28 VDC electric motor. On 47 the right trim tab is mechanically geared to the left trim tab.
How is elevator trim accomplished?
Electric trim motor. Moveable horizontal stabilizer.
How is rudder trim accomplished?
Electric trim control. Located on PCL.
Min prop clearance for nose tire inflated/deflated?
Inflated: 12.5 IN
Deflated: 1.9 IN
Min turn radius?
33ft 6 in
Steering range for nose gear?
With rudder 12 degrees. With brakes, 60 degrees.
How are flaps operated?
Controllable electric selector operating an electric motor, 0, 15, 30, 40.
What kind of flaps?
Fowler-type.
What will cause red flap CAWS to annunciations?
Flap asymmetry of 5 degrees, twist of 2 degrees, flexible shaft failure.
What type of gear? How is shock absorbed?
Tricycle retractable, hydraulically controlled and operated. Gear held in retracted position by hydraulic pressure. Lose pressure, gear will fall. Shock is absorbed through pistons in landing gear.
What kind of brakes?
Hydraulically actuated single disc brake on onboard side of each wheel. Separate from aircraft hydraulic system. Whoever applied most pressure will control brakes between the two pilots.
What kind of engine (model, turbine type, Hp)?
The engine is a Pratt and Whitney PT6A-67B. It is a lightweight, reverse-flow, free turbine, a compressor section having four axial stages and one centrifugal stage impeller, an annular reverse–flow combustion chamber. The engine is rated at 1600 SHP and is flat rated at 1200 shaft horsepower. Supplemental thrust in generated by engine exhaust (jet thrust) accounts for about 6% of total engine power.
How many fuel nozzles and when do they operate?
There are 14 duplex type nozzles, with each nozzle incorporating a primary and secondary valve. During engine start the primary flow begins as soon as there is fuel pressure with the secondary flow kicking in above approximately 45% Ng. Without the secondary flow, the engine may hang at 40-45% NGduring start. For operations from normal idle through max power, all 14 nozzles function with fuel coming from both the primary and secondary valves.
What is the maximum NG?
104% NG
What speed does the power turbine turn?
29,894 RPM, 100% NF
How is the power turbine speed reduced to propeller rotation speed?
The power turbine drives the propeller speed through a Reduction gearbox (RGB) at the front of the engine
When is selection of Beta or reverse range prohibited?
During flight and anytime the engine is shutdown. The PCL is mechanically–linked to propeller hub and will bend and break with no oil lubrication.
What is the minimum oil level for operation?
4 quarts low as indicated on the dipstick
What is the normal oil level to operate?
2 quarts below max hot
What critical element exists with regard to the oil dipstick (other than measuring oil level)?
The dipstick tube is a pressurized part of the oil system, so not properly securing the dipstick will result in oil loss and possible bearing/engine seizure.
Can engine oil brands be mixed?
No; the oil type which is the BP 2380 Green Can.
What is the oil capacity?
Total oil capacity is 14.5 US quarts
When do you check the oil?
MAX HOT (10mins after shutdown) MAX COLD (12hrs after shutdown)
What is the one memory item need for an ENG FIRE CAWS alert?
PULL the ECS SHUT OFF handle
What percentage of the engine intake air is used for combustion and what for cooling?
Approx. 20% of intake air is used for combustion, 80% for cooling.
How does the Air Induction System work?
The engine air inlet is located at the front of the engine under of the propeller spinner. Ram air entering the inlet flows through ducting and an inertial separator system and then enters the engine through a circular plenum chamber where it is directed to the compressor by guide vanes. The compressor air inlet incorporates a screen which will prevent entry of large articles, but does not filter the inlet air.
What is the inertial separator and when is it used?
The Inertial separator system is used to prevent intake of FOD (foreign objects)/ice. Used during all taxi operations, precipitation, and when in visible moisture at temps below 10° C.
How does the inertial separator work?
Intake air is forced to take a hard turn before entering the compressor section. When the inertial separator is opened, the momentum of the objects causes them to not make the turn with the air, and they pass straight through the inertial separator channel out the side of the engine cowling.
What are the elements of the compressor bleed system (with regard to compressor surge
control), and how does the system operate?
Compressor bleed valve system operates between 86-92% Ng to prevent the axial compressor from overloading the centrifugal compressor at low RPM (the axial compressor is much more efficient at lower RPMs). The valve is located between the second and third axial stage (P2.5). P3 (3rd stage axial) air is conditioned (depressurized) into Px, which acts against the bypass valve to close the spring loaded valve as engine speed (and P3 pressure) increases. The spring loaded valve opens when engine speed comes below 92%, until it is fully opened at 86%. Also, some of the heated P2.5 air that is ducted out of the compressor section can be routed to the cabin and defroster for climate control during ground operations.
What is the path of fuel through the fuel system?
Main Tanks - Transfer Jet Pump - Collector Tank[boost pump] - delivery jet pump - maintenance shutoff valve - fuel filter (bypass) - air separator - low pressure switch - cabin firewall shutoff - engine driven low pressure pump (bypass) - fuel/oil heat exchanger - engine driven high pressure pump - filter (bypass) - FCU [PCL, MOR, Condition lever] - Fuel Flow Transducer - Fuel Flow divider (dump valve/EPA can) - 14 duplex nozzles.
What will happen if the ejector fuel pump fails?
When low fuel pressure is sensed (below 2.0 psi) and the Boost Pump switch is in the NORM position; the electric (fuel) boost pump will automatically engage (the FUEL PRESS annunciator will illuminate).
How is freezing of water in the fuel prevented?
By an oil to fuel heat exchanger, which routes hot oil into the exchanger via a heat sensing mechanical bypass valve.
What will occur if there is a blockage in the fuel filter?
A red button will extend above the top of the fuel filter facing the bay door, indicating the filter is being bypassed. This has a preset to open at a pressure of 8 PSI. Maintenance will reset the button once the issue is resolved.
What happens to the excess fuel in the system when the fuel condition lever is moved to cutoff?
Both the primary and secondary fuel distribution manifolds close, and the P3 air forces the fuel into the combustion chamber where it is burned off.
What are the electrical sources?
A 24VDC, 24V / 42 amp-hour lead acid battery; 28VDC, 300–amp starter/generator; 115 amp standby alternator.
Where and how is ITT measured?
ITT is measured between the power and compressor turbines with a resistance thermocouple ITT sensor. (T-5)
At what measured tank level do the FUEL LOW lights come on?
When the respective tank runs to below approximately 20 gallons. 2 per tank, low point of the main tanks, and the high point of the collector tank
What are the starter time limits?
Sequence, 60 seconds off, sequence, 60 seconds off, then sequence followed by 30 minutes off.
What minimum battery voltage is required for a battery start, and a GPU start?
24 volts for battery (fully charged battery), and 1000 amps with GPU.
What is the approximate Ng for engine start?
Stabilized at or above 13% Ng
What is the function of the FCU (Fuel control unit)?
The FCU determines the correct fuel schedule to produce desired engine power in response to the Power Control Level (PCL) and Condition lever movement during normal operations, or MANUAL OVERRIDE (MOR) lever movement during emergency operations.
What does a red annunciator lamp indicate?
A hazardous condition requiring immediate corrective action
What does a yellow lamp indicate?
A cautionary condition exists which requires either attention or action as able
What does a green lamp indicate?
A normal or safe condition or operation of equipment
What does the DAY/NIGHT switch do?
It connects the variable intensity dimming for all the Green and some of the Amber annunciator lights to the ENG INST rheostat when operated in the NIGHT setting.
What doors are annunciated as open with a DOOR WARNING light?
The passenger and cargo doors only
What do the turbine guide vanes do?
They ensure that the exhaust gasses impinge the turbine blades at the optimal angle in order to capture the maximum amount of energy.
What is the normal engine rpm/Ng speed?
1200 rpm at the propeller and 101.6% or 33,000 rpm in the gas generator
How does the FCU (through power control manipulation) control fuel flow?
FCU-Power levers act upon a pneumatic bellows which only increase or decrease the amount of fuel flow at a given rate (prevents runaway in the fuel supply delta for the turbine engine). P3 air acts upon the Ng governor (which conditions the P3 air to Py pressure) and the bellows to increase (or decrease) fuel flow as the power setting is altered, allowing P3 pressure to change, changing Py and pressure on the bellows.
How does the Manual Override Lever operate?
In the event of a pneumatic FCU failure the MOR is used to mechanically control the fuel supply to the engine. Be careful with the lever, as it can overstress the engine if power changes are made to rapidly.
If you accidentally move the condition lever to cutoff when on the ground, what action should
you take?
Do not attempt to reintroduce fuel as this could lead to an engine overheat. You should dry motor the engine to cool it down prior to attempting a normal start.
