PT6A-42 Starter Limitations

[MikeOH58]

Limits are 40/60 -40/60 -40/30(minutes).

Does that mean you have up to 40 seconds per start cycle, or is a cycle met when 40 seconds has been achieved with starter engaged.

ie- First attempt you have starter on for 20 seconds. Does that constitute a full cycle for a 60 second cool off period?

 

[deadstick]

The POH has the following Caution:

"If no ITT rise is observed within 10 seconds after moving the condition lever to LOW IDLE, move the condition lever to FUEL CUT OFF. Allow 60 seconds for fuel to drain an starter to cool, then follow ENGINE CLEARING Procedure."

Since Beech mentioned the starter, I'd say that, regardless of whether you introduce fuel or not, the starter needs time to cool. If you have a fully charged, brand-spankin'-new battery, it could be stabilized and ready for fuel in 15 sec. That starter still got a bunch of amps.

The difference is that in the -10 this is written along the lines of "Starter engage time limits above do not apply to engine starting limitations should abort start procedures become necessary." This is not the case in the Beech manual. The Caution in ENGINE CLEARING is "Do not exceed the starter time limits."

Now stand at attention, and recite verbatim...

 

[Medpilot]

In the real world, most people don't use a timer after starter engagement. I'll start counting in my head and if I get a "no light" or "hung" start, then it's off to call a mechanic. If it doesn't light off on the first attempt then there's most likely something wrong.

 

[ppragman]

In the real world, most people don't use a timer after starter engagement. I'll start counting in my head and if I get a "no light" or "hung" start, then it's off to call a mechanic. If it doesn't light off on the first attempt then there's most likely something wrong.

Bingo. That's how we did it with the 1900. If it takes longer than about 20seconds to reach about 20%n1, there's a bigger problem.