CH47 Powertrain Flashcards
How many transmissions? Name each.
- Forward, Aft. Combining, No1 and No2 engine
How are the transmissions connected?
By two engine driven drive shafts and nine synchronizing shafts.
What are the seven transmission pressure low cautions?
ENG1, ENG2, FWD, COMB, AFT. AUX pressure for FWD, COMB, AFT XSMNS. And AFT SHAFT.
XSMN Caution will illuminate at? PSI
Below 20 PSI
COMB AUX OIL Pressure low caution illuminates at?
Below 10 PSI
What are the oil hot cautions? What Temp?
ENG1/2, FWD, COMB, AFT.
Greater than 140.
What are the transmission chip cautions?
FWD, COMB, AFT, No1, No2, AFT vertical shaft.
When does the chip caution illuminate?
When ferrous material has bridged the gap on the chip detector.
What are the debris screen cautions?
FWD, COMB (LH and RH), AFT, No1, No2 engine transmissions.
When will the transmission pressure high caution illuminate?
Above 90 PSI
At what temp will the ENG XMSN warning illuminate?
190
What does the maintenance panel show?
For each transmission it shows chips, debris, main pressure low, aux pressure low, temp high faults.
What is 1? What is 2?
Draft shaft assembly.
1. Synchronizing shaft
2. Flex couplings. Stainless steel.
Name each and what they do.
- Elastomer shock mount. Reduces vibrations.
- Zerk fitting. Grease fitting. Layered for strength and flexibility.
- Bearing housing
4.Flex couplings.
What is this and what does it do?
Buzz burn off module. Can burn off particles .002 inch in size. Burns faster than caution illuminates. If can’t burn off particle, CHIP will illuminate.
When do you check the COMB XSMN oil level?
Within 30 minutes of shutdown. If shutdown for more than 30 operate rotors for min 5 minutes to verify oil level.
ENG XSMN OIL TEMPS (NORMAL AND HOT CAUTION)
Green is 140 and below. Oil hot caution is above 140.
ID 1 and 2
COMB XSMN OIL PUMPS. Left pump provides main lubrication to COMB XSMN & No 1 engine and right pump provides aux lube for COMB transmissions and No 2 eng XSMN. The engine transmissions do not have aux lubrication systems.
What does this area house and what does the filter button indicate?
Engine transmission filter housing. Button shows the filter bypass visual indicator.
Identify 1/2, 3 and 4
1/2: No 1 and No 2 engine transmission oil cooler. 3: Cooling fan. 4: Oil cooler temp/pressure bypass valve.
How is oil cooled in the engine transmission oil cooler?
A fan which pulls air through the coolers. The fan is powered by a vertical shaft driven by an aux gear in the comb transmission.
Identify 1, 2, 3, 4
1/2: Engine transmission inlet screen housing
3/4: 20 PSI pressure switch
What are these? What pressure is normal? What pressure is high?
Engine transmission pressure transducer. Normal is equal to or greater than 20. High is greater than 90 PSI.
What does the COMB XSMN do?
Combines the power of the engines and transmits it at reduced shaft speed to FWD and AFT transmissions.
When do you check the oil level of the FWD and AFT transmisssions?
After 30 minutes from shutdown
What is this? What does it do?
COMB transmission inlet screen. It filters oil prior to going to the transmission gears and bearings.
What is this and what does it do?
COMB transmission main oil pressure switch. If pressure drops below 20 PSI it illuminates the COMB XSMN PRESS LO
What is this?
COMB transmission chip detector
What is this?
Debris screen/ chip detector assembly. Contains electromesh sensor.
What is this?
Main oil filter. The main lubrication system circulates cooling oil through the two AC generators on the aft transmission
What is this?
Oil pressure transducer for for aft transmission.
