GScholz more ont turbo props:

[Straiga]

The more rice you feed the hamster the faster it goes!

OK!

The less rice the slower it goes!

OK! again

So whats that got to do with anything.

Straiga

[Cobra412]

No offense Straiga but your full of bs with this statement.

 

If you shoved the throttles full forward you would spike the temps first, and probably would have a great bang due to compressor stall. Turbines engines are never cramed full throttle while sitting on the runway with no airflow across the airframe.

Especially considering we do throttle snaps in the hush house from idle to burner on the F-15s with Pratt & Whitney F-100-PW-100 motors to ensure the EEC is properly trimmed.  We do the checks step by step per the technical orders for trimming the motor.  Last time I checked these are turbine engines with the throttles being crammed to burner.  Granted we do each engine seperately but that's purely due to the fact the hold back tool and arresting hook can't handle both engines in AB at the same time.

If a motor isn't trimmed properly then yes it will have a compressor stall when snapping from idle to burner.  That's why we do these checks to ensure the motors won't stall if the engines are slammed from idle to mil or burner in any situation.  I know our aircrews also walk up purely so that if in the event of a compressor stall during take off it will happen early and not during the red zone of take off.  If the plane were to have a compressor stall in this zone the aircraft would come smashing back down to the runway.

Simple fact is if you have a compressor stall because of snapping the motor from idle to burner it's due to an improperly trimmed motor or a faulty Electronic Engine Control.  Newer turbine engines like the Pratt & Whitney F-100-PW-220 or 229 don't have many issues with this due to the Digital Electronic Engine Control and the PS2 probe that monitors airflow down the intake.  These motors can auto trim the motor through the DEEC which drops the compressor stall incidents to a minimum.  Typically you'll see stall stagnations which majority of the time are pilot induced failures.  They'll yank and bank and forget to input throttles and stall the motor in the process.

[hacksaw1]

In the late '70s I had a turn-up license for the GE J-79 for my squadron's F-4s. Once the engine is started, oil pressure and temp stable, there weren't limitations that I recall on how fast you move the throttles, or how far while on the ground, as far as the engine itself was concerned. Also, runups to 90 percent were standard max on the flightline for maintenance. And the pilots would hold mil at the end of the runway, release brakes and go to burner immediately, before there was any significant airspeed.
--- Maintenance war story alert ----
Once electric shop needed fuel tanks completely empty to recal the fuel gauges. The jet mech was burning off the bird's remaining fuel on the flight line, chocks on the main wheels and ONE tie down chain at an angle on the nose wheel. The jet mech got impatient and went beyond 90 percent, (they said he was nibbling burner), the plane was already light from practically no fuel. The plane jumps chocks, the tie down chain on the nose swings the nose around long enough to keep it from crashing into the hangar,  then breaks, and the plane "taxies" at 100 percent several dozen yards across turf till it sinks enough to stop it. The jet mech would-be pilot was passed out in the seat. Dang, plane went hard down for a long time till they magnifluxed the LG.

Another strange maintenance story to make you marvel. Hyd leak somewhere inside the extremely long intake throat of an F-8 Crusader. Hyd shop couldn't find the leak on the outside, whether the plane was turning or not, or on the inside when not turning. So, they asked for a volunteer to "dive the intake" while the bird was turning. They tied a rope on the guy, taped his aural protectors on his head and sent him down the intake of the turning bird. And, he found the leak. Crazy Marines.