Supplementary Procedures
The following procedures cover situations outside normal operation: recovering a propeller that is not on the start locks, starting an engine manually, and testing the Negative Torque System (NTS).
Unfeathering Procedure
The propeller must be on the start locks before engine start, otherwise engine damage may result. If the propeller is feathered — for example, when the previous shutdown was not completed with the Power Levers in reverse — use the unfeathering pump to return it to the start locks.
| # | Item | Action |
|---|---|---|
| 1 | RPM Lever | TAXI |
| 2 | Power Lever | GROUND IDLE |
| 3 | FUNCTION SELECT Switch | HOLD TO UNFEATH |
| 4 | Power Lever | REVERSE |
| 5 | Propeller | CHECK UNFEATHERED / ON START LOCKS |
| 6 | FUNCTION SELECT Switch | RELEASE TO NORM |
| 7 | Power Lever | GROUND IDLE |
Watch the blades move out of feather. You should hear the unfeathering pump running and the start locks engaging as the blades reach the locked position.
The unfeathering pump is limited to a duty cycle of 1 minute ON, 3 minutes OFF. If the pump runs out of oil during this procedure, crank the engine with the starter to scavenge oil from the gearbox back to the oil tank, then try again.
Manual Ground Start
A manual ground start is used when the Auto Start / SRL system is inoperative, when an RPM speed switch is suspect, or when residual EGT is high. Ignition and fuel priming are controlled by the pilot instead of the start computer.
Complete the Before Starting Engines checklist first. Park into wind if possible to reduce starting loads and EGT rise.
| # | Item | Action |
|---|---|---|
| 1 | RPM Lever | TAXI |
| 2 | Power Lever | GROUND IDLE |
| 3 | Propeller | CLEAR / ON START LOCKS |
| 4 | SRL & LIMITER CMPTR Switch | AS REQUIRED |
| 5 | SRL & START COMPUTER Warning Light | CHECK |
| 6 | FUEL Switch | OPEN |
| 7 | Fuel Booster Pumps | TEST / NORMAL ON |
| 8 | FUNCTION SELECT Switch | HOLD TO CRANK |
| 9 | RPM Indicator | MONITOR |
| 10 | MANUAL IGN Pushbutton | PRESS AS REQUIRED |
| 11 | PRIME Switch | AS REQUIRED |
| 12 | Fuel Flow Indicator | RISING AT 10–12% RPM |
| 13 | EGT Indicator | OBSERVE LIGHT-OFF AT 14–20% RPM |
| 14 | Oil Pressure Indicator | CHECK |
| 15 | EGT Indicator | MONITOR |
| 16 | MANUAL IGN Pushbutton | RELEASE AT 60% RPM |
| 17 | FUNCTION SELECT Switch | RELEASE AT 60% RPM |
| 18 | RPM Indicator | MONITOR — STABILIZED AT 65 ±1% |
| 19 | EGT Indicator | CHECK STABILIZED |
| 20 | SRL & LIMITER CMPTR Switch | AS REQUIRED |
| 21 | Oil Pressure Indicator | CHECK |
| 22 | EXT POWER Switch | AS REQUIRED |
| 23 | RPM Lever | AS REQUIRED |
| 24 | SRL & START COMPUTER Warning Light | CHECK OUT ABOVE 80% RPM |
| 25 | GENERATOR Switch | RESET / ON |
| 26 | Warning Panel | SCAN |
Notes on the steps:
- Step 3: if the propeller is feathered, carry out the Unfeathering Procedure first.
- Steps 4 and 20: set the SRL & LIMITER CMPTR switch to OFF if an RPM speed switch is suspect, or to SRL if the SRL / Auto Start computer is inoperative. After the start, set it to OFF if the computer is inoperative, otherwise to BOTH.
- Step 5: the warning light should be on unless the SRL & LIMITER CMPTR switch is OFF.
- Step 7: switch on the AUX pump and check fuel pressure and its green light, then switch it off. Repeat with the NORMAL pump and leave it on. The FUEL PRESSURE warning light should go out.
- Step 10: press MANUAL IGN at 15% RPM if residual EGT is above 200°C, otherwise at 10–12% RPM.
- Step 11: if the SRL / Auto Start computer is inoperative, hold the PRIME switch until light-off and use it as needed to keep the engine accelerating.
- Step 15: observe the EGT limit of 770°C (1 second maximum).
- Step 22: during GPU starts, set EXT POWER to OFF before completing steps 23 to 25.
- Step 23: during battery starts, advance the RPM Lever above 80% RPM before switching on the generator.
- Step 25: during battery starts, wait until the ammeter reads below 80 A before starting the other engine.
Abort the start if light-off (a rapid EGT rise) does not occur within about 10 seconds of reaching 10% RPM, if there is no oil pressure within 10 seconds of light-off, or if the SRL & START COMPUTER light stays on after 60% RPM.
NTS Test Procedure
The Negative Torque System limits the torque the propeller can drive back into the engine when windmilling, preventing high drag. Test it on the first engine start of the day, or before a planned engine shutdown for training. The test can be done while starting or while cranking the engine.
Do not take off if the NTS does not test correctly.
| # | Item | Action |
|---|---|---|
| 1 | Power Lever | FLIGHT IDLE |
| 2 | NTS CHECK Switch | HOLD TO ON |
| 3 | NTS CHECK Light | CHECK ON |
| 4 | Power Lever | GROUND IDLE |
| 5 | NTS CHECK Light | CHECK OUT |
| 6 | Power Lever | FLIGHT IDLE |
| 7 | NTS CHECK Light | CHECK ON |
| 8 | Engine | START OR CRANK AS REQUIRED |
| 9 | NTS CHECK Light | CHECK OUT |
| 10 | RPM Indicator | MONITOR |
| 11 | NTS CHECK Light | CHECK ON |
| 12 | NTS CHECK Switch | RELEASE |
| 13 | NTS CHECK Light | CHECK OUT |
Notes on the steps:
- Steps 1–7 check the NTS lockout valve.
- Step 8: to crank without starting, hold the FUNCTION SELECT switch to CRANK.
- Step 9: the light goes out as the engine begins to rotate, showing that the NTS has sensed negative torque and moved the feathering valve.
- Steps 10–11: the light comes back on once the engine passes 25% RPM.