View Full Version : PT6 Engine care..

25th Mar 2009, 15:08
Hi Guys,

I would appreciate your inputs on pilot engine care, especially on the PT6 range for B1900's.

Currently we advise our crew to do:

1. Bleeds off, Environ off t/o
2. Reduce pwr t/o - runway permitting
3. Start into wind
4. 2 min idle before shutdown
5. Start with ITT below 200 deg C on through flights.
6. Good Bat V

Any other tips will be appreciated:ok:

25th Mar 2009, 15:19
All of that is good, just remember to stay within flight manual parameters

25th Mar 2009, 17:52
At first glance it sounds a little overboard. But with the temperatures you guys see down there I can see why you wouldn't want the flowpacks on until after takeoff anyway.

How do you figure out a safe power setting for the reduced power takeoffs?

We run our PT-6s consistently at redlines and almost always get over 10 000 hours between overhauls.

2 minute idle is an excellent rule.

25th Mar 2009, 18:29
The numbers are good. Max motor for start before introducing fuel is important (rather than introducing at minimum %ng). Cool down with bleeds off, of course.

Ground power is always preferred on the starts; you'll get higher max motor, and cooler starts.

26th Mar 2009, 03:44
V1.Ooops has some very interesting stats about multiple fatal accidents in DHC-6 (PT6 powered) - 7 out of the last 10 would have been avoided if the pilots had used full takeoff power as specified in the POH for takeoff. Bending an airframe will cost far more than trying to get a bit more life out of the engine will save.

My gospel tips:

Don't exceed any limits in the POH - particularly climb torque and cruise torque limits. Some of these figures may be buried in the performance section of the POH.
Do compressor washes religously if operating in salt laden air. In Aus CASA define salt laden air as within a set distance of the coast below 10,000 feet, if flown there a daily ct wash is required. (The distance doesn't affect me as I fly C208 amphib seaplanes off salt water.)
Use the inertial separator when FOD is a possibility.
Engage brain before touching the condition lever.
Minimum 1 minute idle AFTER ITT/T5 has stabalised before shutdown.Some other things that I beleive will help:

On the surface move the power lever slowly when coming off idle to reduce the temperature spike, however in flight move the lever as quickly as is appropriate for the situation.
Once clear of obstructions reduce power to keep ITT/T5 below cruise limits.
Avoid unecessary starts - get a fuel truck to bring fuel to you rather than taxying to the bowser, use hot turn procedures if safe and operator procedures are in place.
Introduce the fuel as the Ng approaches it peak - any earlier and the start will be hotter, any later and there is unecessary wear on the starter system and less energy in the battery.
Avoid depleting the battery before start, use external power if available.
Minimise bleed and accessory loads for take off.
Use reduced power takeoffs to reduce ITT/Ng only if safe. If no reduced power take off charts are available select a high ambient temperature that has a torque limit for takeoff - if you use this torque as the takeoff setting the performance charts will be conservative - they take into account this reduced power setting as well as air density.Well that's my $0.02 anyway.

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