Static thrust testing

[flyboykelly]

Has anyone done a static thrust test with an o-320 or O-360 powered rv. Data with a fixed pitch prop is Preferable.

Thanks!

[bruceg]

Cessna 170, 172 &175
MT Propeller Performance Test Results
Flight Resource, LLC for STC # SA02245CH
Engine: Lycoming 0-360-A1A, 180HP @ 2700 rpm
Ambient conditions: 1000 MSL and 75F aircraft at #2550 lbs
Propellers Tested:
MT MTV-15-B/210-58. 83? 2-blade composite prop. (Constant speed)
MT MTV-15-B/205-58. 80? 2-blade composite prop. (Constant speed)
McCauley 1A200DFA 82/42. 82? 2-blade aluminum prop. (Fixed pitch)
Hartzell HC-C2YK-1A 74? 2-blade aluminum prop. (Constant Speed)
Hartzell HC-C2YK-1BF 80? 2-blade aluminum prop. (Constant Speed)

Static Thrust (2700 rpm):
MT 2-blade 210 cm 806 pounds
MT 2-blade 205 cm 790 pounds
McCauley 2-blade (2450 RPM) 750 pounds
Hartzell 2 blade 74? long 625 pounds
Hartzell 2 blade 80? long 737 pounds

[Kyle Boatright]

Out of curiosity, what is the intended use of the static thrust info?

The reason I ask is that static thrust is important for helicopters, but doesn't translate well into our world of 50-225 mph airplanes.

[flyboykelly]

Bruce, thanks for the info!

Kyle, my application has nothing to compare to. So I'm gaining data to check that my propeller/engine combo are going to provide the needed performance before I attempt a takeoff.
The plan is to do a static thrust test at full power on my airplane. Then do the same on another lycoming powered rv. Then we are going to flight test that rv at the numbers of the radial powered airplane. This way I know the exact flight characteristics before I attempt a first flight.

[pierre smith]

Leland Snow used to test the P&W 1340 cu. in. engines on the Air Tractors, using a scale attached to a post embedded in concrete, in Olney Texas.

Be careful in doing this...it puts all that load on the fuselage skins and/or tailwheel attach fittings.

I'd run this idea by Van's first.

Good thinking though.

Best,

[DanH]

Small hydraulic cylinder and a pressure gauge. Dismantling the cylinder to measure the exact area of the piston allows converting PSI to force.



Brain, the RV8 can be restrained very well with a stout rope or strap yoke at the top of the gear legs. Make the yoke long enough to loop out past the tailwheel and drop it over the hitch ball on a full size pickup truck. Don't hold the brakes during the runup.

[Kahuna]

Originally Posted by Kyle Boatright

Out of curiosity, what is the intended use of the static thrust info?

The reason I ask is that static thrust is important for helicopters, but doesn't translate well into our world of 50-225 mph airplanes.

Kyle it actually translates pretty well. When we went to the composite Hartzell blades, we picked up ~150lbs of thrust. That translated to:
Shorter take off runs in the order of ~125'.
Higher vertical penetration
Longer tail stands
Better rotation on hammers and at slower speeds
Higher thrust at slower speeds creates wingman confidence in aerobatic maneuvers allowing for longer hang times.

Believe me when you get more static thrust from your plane you will feel it and see how it impacts your performance.