Piston VS Turboprop Engine Lag!!! Aviation and Pilot Training

[davidbadt]

Whole engine is a turbo but it still spools quicker than most boosted civics😂

[tywheeler]

Half the training planes i flew had a delay and a backfire… so we’re good :)

[theslayeroforyx]

A little fact about the PT6 engine is that because it’s a free turbine you can hold the propeller if you start the engine and don’t add fuel. Same thing cannot be said for the TPE-331 because if you try to hold the propeller as you start a Garrett the torque will lift you off your feet.

[stevep]

That simple demonstration with explanation was invaluable!

[mountainmikeoutdoors]

I generally bring the torque back to the bottom of the green line to start configuring for landing. 200lbs is my personal minimum. That delay is different for each engine when your TT is 63, 000 hours. I brought it all the way to flight idle in a descent once and then brought it back up to low cruise. It took one engine 6 seconds and another 3. Weirdest yaw of my life. So I just keep em a little spooled so I don't have to deal with that.

[dieselyeti]

King Air pilot here. It's not a big deal.

[Tom-muzy]

The delay is more caused by the fuel control than the free turbine. The second valve in the FCU opens wider as the air pressure P3 rises. This slows the addition of more fuel fuel to prevent temperature spikes. You can see the smooth gradual increase in fuel flow and N1 and therefor the air that drives the prop section, during the start sequence and when going from idle to full power.

[Cleetustwatwaffle]

Had the same engine in our DHC-2T on floats. Lovely setup especially for tight docking situations.

[CallsignMunch]

Wait till you see how long it is in jets! Big part of the transition from Turbo-Props is the being ahead of the power.

[michaelmcdonald]

Sounds like my Audi. Three to four seconds after I am out in the damn intersection the turbo decides to spool up! Be safe out there.

[doodskie]

Still less delay than my diesel truck's boost lol

[michaelhenry]

My man explaining the basics of a turbo that's been known for 30 years

[Hossman]

You are sort of correct. The free turbine assembly of the PT6 is not a contributer of lag.

[riverwildcat]

This delay keeps the turbine blades in the combustion chamber from melting from the surge of fuel and heat. Cool intake air requires a few seconds to arrive in the middle inferno.

[Account]

This is exactly the tip I got when I was right seating on a PC-12. Honestly it wasn't a big deal since most of the pistons I fly are either clapped-out sh**boxes with engines that want to sputter on every occasion or those with those annoying Vernier throttles that you have to twist like mad to move an inch.

[ghost_fpv]

That spool up is dangerously seductive and never gets old with the C90 I fly. Happy flying dude!

[nastygollum]

Congratulations on your transition. So brave.

[truevegas]

As a MFSF2020 PIC, I thank you for this information 👨‍✈️

[CKILBY-zufq]

IN street racers, they use nitrous oxide to cause the turbo to spin faster with a burst of nitrous. This lessons the turbo lag. Peace.

[snoopyfix]

Love your content man. I'm a ppl right now. I appreciate any info you give. 👍👍