Caravan AD... Ouch!

That's why even though you can add fuel at the minimum Ng/N1/whatever your manufacturer calls it, sometimes it's a good idea to let the ITT/ /T6/whatever your manufacturer calls it come down before you add fuel again on a quick turn. That "whump" noise if you add at exactly 12% Ng with a hot motor on a quick turn can't be good for the hot section.
"Whump" noises are generally bad in aviation...in my experience.
 
We teach separator open after start, closed before takeoff, open after landing, and closed before shutdown. And of course the typical in-flight stuff.

I've got a realllllllllllly cool story about shutting down with the separator open and a tailwind with a full EPA can and getting to meet the Portland Airport Fire Department.
:)
 
We teach separator open after start, closed before takeoff, open after landing, and closed before shutdown. And of course the typical in-flight stuff.

I've got a realllllllllllly cool story about shutting down with the separator open and a tailwind with a full EPA can and getting to meet the Portland Airport Fire Department.
:)
EPA can? Real engines burn that shizzle in a pre-shutdown burst of power, noise, and beta.
 
We have ours open any time we're on the ground.


Yea 99.9% of the time I do as well, but on those sub 45 minute turns when the OAT is above 30C with no wind, the ITT can be in the low 200s before you even hit the starter. That extra airflow with the door closed keeps a warm start from being a "Start counting when the temp hits 860" start.
 
We hook up the Garrett start pack to our one pratt van and it starts nice and cool, and then proceed to curse at it for being a dog trying to climb out.
 
That's what I do, at least - I generally like to see cooler than 150° but that's just me.
THIS!
Yea 99.9% of the time I do as well, but on those sub 45 minute turns when the OAT is above 30C with no wind, the ITT can be in the low 200s before you even hit the starter. That extra airflow with the door closed keeps a warm start from being a "Start counting when the temp hits 860" start.
On days like these I always hand turn the prop for about a minute right after shutdown. You can literally drop the ITT a couple of hundred degrees! One quick spin after taking off the prop tie down (if installed) or hopping in for the start will reduce it by about 80 degrees. Doing this, rarely have I seen my ITT get close to the 800 mark.......
 
THIS!

On days like these I always hand turn the prop for about a minute right after shutdown. You can literally drop the ITT a couple of hundred degrees! One quick spin after taking off the prop tie down (if installed) or hopping in for the start will reduce it by about 80 degrees. Doing this, rarely have I seen my ITT get close to the 800 mark.......
Doesn't Pratt recommend against that since you're not running the oil pump when turning just the power turbine? Though I doubt you're turning fast enough to hurt anything, I'm pretty sure that's the whole reason for the prop tiedowns.
 
Doesn't Pratt recommend against that since you're not running the oil pump when turning just the power turbine? Though I doubt you're turning fast enough to hurt anything, I'm pretty sure that's the whole reason for the prop tiedowns.
Never heard of this, you might be right. However, in a hot/warm engine there is enough oil in the prop section if that is a concern. You would be surprised at the reduction in ITT though.
The reason for the prop tie down is so someone doesn't get hit while walking by on a windy day or so the prop doesn't hit the tug.
 
Turning the prop on a free turbine isn't going to cool anything. Where it is hot is the part that isn't connected to the prop. On a honeywell/garret it is almost mandatory especially in the summer in Texas.
 
THIS!

On days like these I always hand turn the prop for about a minute right after shutdown. You can literally drop the ITT a couple of hundred degrees! One quick spin after taking off the prop tie down (if installed) or hopping in for the start will reduce it by about 80 degrees. Doing this, rarely have I seen my ITT get close to the 800 mark.......
The ITT probe is directly above the split between the power turbines and the compresssor turbines, so I don't see how you would see any change by spinning the prop.

PT6-1.jpg
 
The ITT probe is directly above the split between the power turbines and the compresssor turbines, so I don't see how you would see any change by spinning the prop.

PT6-1.jpg
Try it and see. Have someone turn the prop while you sit in the cockpit and watch the gauge. Turning the prop will draw cool air through the engine.....seriously...it works!
 
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