Static Engine Thrust

[HercFan]

Does anyone have numbers for the test stand maximum static thrust for the various engine and prop combinations used on the Herc over the years? I'm interested in doing some theoretical comparitive takeoff performance calculations for the standard USAF Herc models A,B,E,H,and J. The method I'm using is based on some simplified thrust-to-weight equations and works better with actual test stand results than by using the handbook spec figures for shp and torque. Am particularly interested in the A,E,&H all of which I flew. Thanks

[herkman]

We were always taught that the T56 had 1,000 lbs of thrust at take off.

Not bad when you consider that our primary jet trainer could only come up with 3200lbs at maximum power.

Regards

Col

[Wombat]

The National Museum of the USAF quotes 800lbs tailpipe thrust with a max operating altitude of 55,000ft for the -7 series. You can check their blurb out of their site under T56. Turbo-props are optimized to provide drive shaft torque in lieu of thrust. An Allison engineer I did some work with some years ago said the turbine actually supplies about 9,000 shaft hp at the turbine coupling shaft front coupling and losing the rest to driving the compressor and reduction gearbox. He also said the unshrouded thrust was about 1,000lbs with about 200 lbs being lost due to the downward angling of the tailpipe. AC-130 crews will tell you there is a noticable increase in fuel burn due to the IR shrouds sometimes fitted over the tailpipes.

[victorp1]

The T56-A-15 with OAT 15 degrees C, sea level, no bleed, and zero knots airspeed:

Prop thrust 8900 pounds

TIT 1077°

Torque 21,160 inch pounds

Fuel flow 2460 PPH

This may help you.

Vic

[SEFEGeorge]

I seem to recall that the -1-1 listed the engine performance based on a 95% engine.