Thrust And Hp

[Scotty 1]

Hi All

 

A mate wanted to know how much HP an auto conversion was putting out. Without a chassis dyno, hard to say. So we hooked a digital scale to the tail wheel on mine, tied it off to his Land Rover and then ran it to figures from the manual for the 912 uls.

 

Power RPM HP What it pulled

 

55% 4300 50 137 kg

 

65% 4800 60 175 kg

 

75% 5000 68 198 kg

 

max cont 5500 90 237 kg ( prop set to 5400 static)

 

We then used those figures as a guide and then ran his through the rev range. Lets just say he is not a happy chappy.

 

As this was only a guide we didn't worry about rolling resistance or get too tecnical as both plane are in the same weight bracket.

 

Anyone else done anything like this? Doesn't seem like enough thrust to keep 600kg in the air but as I can fly around 4000 RPM @ 60 knots (or slower if all is ok) in mine it must be.

 

Cheers Scotty