Oil System

Question 1

Normal oil pressure range above 72% NG is ___

Answer 1

90-135 PSI (green range)

Question 2

Decrease in oil pressure below 90 PSI may indicate what?

Answer 2

Opening of the filter bypass as a result of a blocked oil filter

Question 3

What is the minimum oil pressure with a power setting below 36 TRQ PSI (normal oil temp)?

Answer 3

85 PSI.

Question 4

What is the maximum power setting at Oil Pressure 60 – 90 PSI?

Answer 4

23.9 TRQ PSI

Question 5

What should you do if Oil Pressure falls below 60 PSI?

Answer 5

Land ASAP

Question 6

What is the total oil system capacity?

Answer 6

3.6 US GAL / 13.6 litres

Question 7

What is the optimal oil temperature?

Answer 7

74 to 80 degrees. (or just 80, as that is the middle of the green on the LCD)

Question 8

What is normal oil temperature?

Answer 8

55 to 105 degrees (green arc).

Question 9

What is the minimum oil temperature for engine start?

Answer 9

-40 degrees.

Question 10

What is the minimum required oil temperature for takeoff?

Answer 10

10 degrees.

Question 11

What oil temperature range is allowed for no longer than 10 min?

Answer 11

105 degrees to 110 degrees.

Question 12

If the Oil is low, when will the Oil Qty CAWS come on?

Answer 12

60 seconds after shut down OR 60 seconds after turning on battery.

Question 13

Upper Oil Pressure transient range:

Answer 13

135 PSI to 200 PSI for 20 seconds.

Question 14

Lower Oil Pressure transient range:

Answer 14

40 PSI to 60 PSI for 20 seconds.

Question 15

What is MAX HOT and MAX COLD refer to regarding shot down time?

Answer 15

Max hot = within 30mins of shutdown

Max cold = 12hrs after shutdown

Question 16

What is the engine pressure system ran off?

Answer 16

The accessory gearbox.

Question 17

What could be a possible reason you are observing a drop in oil pressure?

Answer 17

Oil filter has become all or partially blocked, and it has now opened the oil by-pass valve.

NOTE: a check valve will permit 15 PSI of oil pressure through the oil filter

Question 18

What is the path of the oil system?

Answer 18

1. Oil tank screen
2. Oil pump
3. Pressure regulating valve (90-135)
4. Pressure relief valve
5. Oil filter (bypass valve)
6. Engine accessories
7. Scavenge pumps (gravity fed from engine accessories)
8. Oil strainer
9. Fuel exchanger (oil-to-fuel heat exchanger)
10. Back to tank