Oil System Flashcards
Engine oil pressure decreased to 25 psi with the throttle in the idle position. What action if any must the pilot take?
None…… pressure at idle is minimum 20 to 30 psi., 30 to 100 is normal, 100 to 120 is a 5 minute limit, and 120 is maximum.
Where can you find a list of approved oil for the Engines, APU and transmission?
(RFM page 1-19)
How is engine oil cooled during engine operation?
Fuel to oil heat exchange (liquid to liquid cooler)
IPS discharge air passing over the scroll vanes
Describe the transmission lubrication system.
Dual pumps mounted on the front of the MGB
MGB oil cooler- External to the MGB, radiator and a blower driven by the tail rotor drive shaft
Bypass valve provides control by the pilot to bypass the oil cooler
Oil filter has a bypass indicator
If one of the transmission oil pumps fails, what transmission oil pressure would you expect to see?
Pressure fluctuations between 5 and 25 PSI.
With a failure of one of the transmission oil pumps, what CAS lights will the pilot immediately see?
- MGB OIL PRES warning illuminates when oil pressure at the manifold falls below 35 psi and pressure at the last “jet” falls below 24 psi.
- MGB OIL PRES caution illuminates in flight when gearbox pressure at the manifold falls below 45 psi or pressure at the “last jet” falls below 24 psi
What is the immediate pilot action when the MGB OIL PRES light illuminates?
Select MGB OIL BYP within 5 seconds.
With the MGB OIL PRES warning or the MGB OIL PRES or MGB OIL HOT caution illuminated what symptoms of an imminent gearbox failure would change the landing criteria from Land as soon as Possible to Land immediately?
MGB oil pressure below 5 psi
Increased power required at constant collective setting and airspeed Yaw kicks
Unusual noise or vibrations
Loss of two hydraulic pumps
When would the TGB or IGB OIL LEVEL caution illuminate?
Oil level 66% of full as measured by a liquid optical sensor in the GB Rotor not turning since DCU power up or has been stopped (NR<10%) for 2 minutes
Aircraft on the ground (wow)
Engine NG at 0%
When conducting a cold weather start (temperature below 0 C) you note the oil pressure exceeds the maximum pressure (120 psi red line). What are the pilot actions?
Run the engine at ground idle until oil pressure is within normal operating limits. It may take as long as 6 minutes before pressure will return to the normal operating range