PHI GOM S-92A - POWER TRAIN Flashcards
S-92 Power Train
What angle is the main rotor mast tilted?
5° forward tilt.
What sub assemblies make up the Main Transmission Assembly?
Main module
2 input modules
2 accessory modules
The input modules reduce high-speed shaft RPM from ______ to ______ RPM.
About 22,000 RPM from the HSS to 7,500 RPM input to the maintrasmission.
What is the oil capacity of the MGB?
10.5 gallons
How is the MGB system oil cooled?
External cooler radiator and blower assembly.
Below what temperature will MGB oil bypass the cooler?
55°C
MTM 63-35
How many times does the fuzz burn attempt to clear the chip before turining on the CHIP light?
6 pulses.
If the chip is 45 ohms the light will illuminate
Where are the Nr sensors located?
Where does each of the two Nr sensor’s information go?
1 and #2 Accessory Module.
DCU (for PFD display)
AVC
What condition will illuminate an MGB OIL HOT caution?
Oil temperatures above 130°C.
How many chip detectors are monitored by the chip detector processor?
9 total (2)1 in each input module (2)1 in each accessory module 1 in the main module 1 in the IGB 1 in the TGB (2)1 each engine
What is the function of the chip detector processor?
Monitors all 7 power train chip detectors,
commands or disables ‘fuzz-burn’, and
sends information to the DCU for chip caution segments.
Under what circumstance will fuzz burn be disabled?
Oil temperatures above 130°C. (140 for TGB)
What accessories may be affected by overheating MGB oil?
AC Generators may fail since they are dependent on MGB oil for cooling.
What limitations exist when starting the engines with the rotor brake engaged?
Minimum 450 p.s.i. at the rotor brake.
When engines are started and brake released,
1 minute at idle required for even heating of the power turbine blades (to prevent turbine rub).
What conditions will cause a ROTOR BRAKE caution to illuminate when WOW?
Rotor brake proximity switches indicate the piston is still engaged
OR
>8+/-2 P.S.I. measured at the pressure switch.
What conditions will cause a ROTOR BRAKE caution to illuminate when in flight?
Rotor brake proximity switches indicate the piston is still engaged
AND
>8+/-2 P.S.I. measured at the pressure switch.
In flight, BOTH conditions must be true so that it is not likely that the caution is a false indication.
If a TGB CHIP and TGB HOT caution are illuminated, the pilot should land as soon as practical, possible, or immediately?
Immediately
Where is the freewheeling unit located?
Input module
MGB OUT WARNING illuminates and “GEAR BOX OUT” audio when?
less than 5P.S.I. at the input manifold
AND below 24 P.S.I. at the last jet.
MGB PRES WARNING illuminates and “GEAR BOX PRESSURE” audio when?
less than 35P.S.I. at the input manifold
AND below 24 P.S.I. at the last jet.
MGB PRESS Caution illuminates?
less than 45P.S.I. at the input manifold
OR below 24 P.S.I. at the last jet.
