Prog 1 Excel Tester.xlsm - Propeller System Flashcards
On Engine NO. 1 & 4, the NTS system is activated by what SHP:
-150 to -500 SHP
On Engine NO. 2&3, the NTS system is activated by what SHP:
-100 to -500 SHP
Normal RPM Limits
96.3-99.1%
- What is the Sequencing priority for the autofx system?
4-1-3-2
At what time does the Back-up valve open?
When Coord. Is below 28º
Offspeed Propellers – (Overspeed or Underspeed)
An RPM indication in excess of 1 per cent above or below normal governing RPM and detected audibly is considered an offspeed. This malfunction may be caused by the SYNC system or the propeller governing system.
Fx Valve/NTS Check Light (Cause)
Cause: Fx valve is functioning properly during an inflight restart. Light is on steady when e-handle is pulled
What requirements are necessary to activate the (TSS) autofeather system?
- System must be armed (switch on );
- power lever greater than 60 deg coord;
- THRUST drops below 500 lbs
- no feather buttons in
Stby Prop Pump 2 output
40qt/min
What does ‘Prepare for Pitchlock’ mean?
It means increase airspeed and altitude to that required to safely make your destination in anticipation of the propeller pitchlocking
The inner shaft on the torquemeter is connected to both the power section & the RGB, while the outer shaft is connected only to the pwr section. Why?
The inner shaft is connected at both ends, and is twisted when pwr is applied. The outer shaft is connected at only one end and is not twisted. The deflection between the 2 shafts gives us a SHP reading
List 2 ways that pitchlock can be actuated.
- Loss of controlling prop fluid pressure;
- Overspeed of 103.5 % rpm
What are the two main categories of propeller malfunctions?
Featherable and Non-Featherable
In flight the beta follow up system acts to(x3):
1.acts as a low pitch stop above 72 Deg Coord;
2.prevent overspeed in response to rapid power lever movement;
Airstart speeds if range is critical
A maximum of 345 KIAS at sea level, reducing 6 KIAS/1000 feet, should be used if range is critical.
What are the rpm limits for low rpm?
71.0 - 73.8 %
At what RPM does the pitchlock system engage?
103.5%
Mechanical Methods to Feather prop x2
- Negative Torque System;
- E-Handle
What is the danger associated with the prolonged operation of a decoupled propeller with the power section shutdown?
The RGB could be starved of oil in as little as 30 minutes, resulting in a fire or possible prop separation
Auxiliary Fx pump Normal Power Sources
(AC) 3 Phase AC Power Bus = B A A B;
(DC) Control DC Power Mon EX EX Mon;
Alter AC Power Bus A 1 & 4
BETA Light
indicates the B/A is less than 10 degrees or less ; serves as a visual confirmation that the B/A is decreasing as the power levers are retarded towards reverse.
What is the danger associated with E-handling a pitchlocked propeller?
Without enough controlling fluid to fx the prop the teeth will disengage momentarily allowing CTM to drive the prop to a finer blade angle. This reduces max possible airspeed and altitude and therefore range.
What are the 2 purposes of the interconnecting structure?
- transmits pwr from the engine to the RGB
- aligns & supports the engine & the RGB
Why does pitch lock stop at 57º BA?
To allow for feathering
CHIPS light
indicates that metal particles are flowing through the oil system of either the RGB or the Engine or both.
Which component is used to electrically actuate the three methods of electrically feathering the prop
Feather Valve Solenoid
What are the 2 subsections of the prop control assembly & where are they located?
- valve housing - at the top
- pump housing - at the bottom
38.In the flight range, the RPM is controlled by:
Prop Governor
PCO for __ seconds before air start allows the feather pump to _________________________and verifies operation of the ___________________________
PCO for 10 seconds before air start allows the feather pump to re-pressurize the prop Dome and verifies operation of the Feather Solenoid Valve
all four AutoFx Lights illuminated (Cause)
AutoFx is armed in all Four engines.
NTS Check Light Indicates:
NTS has occurred; will remain steady on
Takeoff RPM limits to allow for an over/undershoot
96-106%. Stable within 10 seconds.
What components comprise the interconnecting structure between the power unit and the RGB (x3)?
a. the torquemeter
b. 2x tie struts
c. Safety Coupler
When OAT is LESS THAN -10 degree C (x3)
- conduct normal engine starts
- monitor engine oil temp until 40 deg
- do not move power levers from start position until engine oil temp is 40 deg C
Power Levers are restricted from being retarded into the ground range in flight by two means
- A physical Ramp in the Power Level Quadrant
- The Flight Idle Stop
What items make-up the Prop Governor? (x4)
- Fly weights
- Pilot valve
- Servo valve (spool
- Speeder springer
What are the rpm limits for normal rpm?
96.3 - 99.1 %
When power levers are below 28 deg coord & blade angle is above 10 deg, a pitchlock reset solenoid allows up to _____ rpm, to avoid pitchlock when the power lever is retarded very rapidly into ground range and the blade angle decrease is slow
109 % rpm
The safety coupler will disconnect the engine from the prop in cases of extreme drag when ______ SHP is reached.
-1700
What is the 45-deg airstart protection system?
A backup for a failed NTS during in-flight unfeather operations. At 45 deg B/A, the feather solenoid valve is energized and de-energized cyclically to optimize the airstart blade angle.
When is the 45 deg airstart protection available? (x3)
Feather Button held in the UNFTHR position
Pressure Cutout Overide (PCO) button not depressed
Blade angle less than 45 degrees
How can you tell if a propeller is pitchlocked or not?
RPM will follow power lever movement
When would you ‘Prepare for Pitchlock’?
When you are faced with a propeller malfunction not adequately covered by one of the Propeller Procedures or at any time you believe there is a possibility a propeller might pitchlock.
Electrical functions of E-handle (2F BEO)
(F) Feather valve solenoid (actuates
(F) FCU (shuts off fuel
(B) Bleed air shutoff valve (Closes
(E) EDC (dump) Firewall shutoff valve(Close
(O) Oil tank Shutoff Valve (Close)
In the ground operating range, blade angle is controlled by _______.
Power lever(Coord) position
Fx Cutout Switch cam in the beta shaft prevents px surges from terminating the fx process until
B/A reaches 74 Deg or more
What is the definition of an RPM fluctuation?
An RPM Fluctuation is a sustained cyclic RPM oscillation which can be detected audibly and is possibly followed by corresponding fluctuations of TIT, SHP, or fuel flow.
Mechanical Functions of the E-handle (3F Gen)
(F) FCU (shutoff
(F) Fx Valve (mechanically moves it to the Fx position
(F) Fuel Tank Emergency Shutoff Valve (closes
(GEN) Generator Cooling Air Shutoff Valve (Closes)
Max reverse is equal to what coordinator position ? What blade angle?
0 degrees coord / - 13 degree blade angle
Outside the range of pitchlock allows for what?
Unfeathering ( Pitchlock cammed out in the ground range)
normal rpm Limits (Ground):
96.3 - 99.1 %
What are the Prop Fx Pump power sources?
B-A-A-B
Alt A for 1 and 4
Mon-Ex-Ex-Mon
What 2 features are available with the sync servo switch in the normal (on) position? (x2)
- Anticipation circuitry - limits rpm transients caused by rapid power lever movement
- Speed derivative circuitry - limits rpm transients caused by changes in power plant load
Explain the ASR relationship?
TAS + SHP = Inverse relationship
TAS + RPM = Positive relationship
What is purpose of the RGB?
Coverts the engine high rpm low torque energy, to low rpm high torque energy that can be used by the prop
What is the minimum blade angle for Beta follow-up at 90º Coord
22.5 º
The prop’s response to an overspeed condition is to ( increase / decrease ) blade angle.
Increase