Engine Limitations

Question 1

Minimum Battery Voltage for GPU Start

Answer 1

20 V

Necessary to ensure enough power will be available for the explosive squib in the event of an engine fire.

Question 2

Minimum Battery Voltage for Battery Start

Answer 2

23 V

Necessary to ensure enough power will be available for the explosive squib in the event of an engine fire.

Question 3

Starter Temp Limit

Answer 3

1000 C for a maximum of 5 seconds

Question 4

Maximum amount of time the starter may be engaged for before ignition occurs?

Answer 4

Maximum of 20 seconds. If ignition occurs before this, there are no limits on how long the starter may be engaged for.

Question 5

Assuming the first engine start was aborted, how long must the starter be allowed to cool down before attempting a second start?

Answer 5

30 seconds of cool down time following the first start.

Cool down time begins once the starter is turned off.

The starter may be engaged again for 20 seconds following the cool down period.

If fuel was introduced during the previous aborted start attempt, the starter should be motored for a maximum of 20 seconds before attempting to start again. Following engine clearing, the starter should be allowed to cool down for 60 seconds before attempting to restart the engine.

Question 6

Following a second attempted start of the engine, or clearing, how long must the starter be allowed to cool down before attempting a third start?

Answer 6

60 seconds

Question 7

Cool down time required after an aborted third start attempt?

Answer 7

5 minutes.

Question 8

Cool down time required following a normal start?

Answer 8

5 minutes

Question 9

Minimum oil pressure required for operation?

Answer 9

90 psi is undesirable, and requires that torque be limited to 2000ft-lbs. This is because the torque-meter recieves its information from oil pressure, and a low oil indication will cause incorrect readings on the torque-meter. 2000ft-lbs ensures the pilot will not exceed 3750ft-lbs of torque.

60 psi is considered unsafe.

Question 10

Takeoff ITT and Torque limitations?

Answer 10

3950ft-lbs of torque and maximum ITT of 800 C, whichever occurs first. For a maximum of 5 minutes.

Props should be set at 1700RPM

Question 11

Max. Continuous Power Setting?

Answer 11

3750 ft-lbs of torque and ITT of 780C, whichever occurs first.

Props should be set at 1700RPM

Question 12

Cruise Climb and Max Cruise Setting?

Answer 12

3750ft-lbs of torque and ITT of 760C, whichever occurs first.

Props should be set to 1700RPM.

Question 13

Transient power limitations

Answer 13

5000ft-lbs of torque and ITT of 870C, 1870RPM

limited to 20 seconds.