I have 3 different propellers to test;

Lang LA10 66" diameter 28" pitch
Flottorp 6628 66" diameter 28" pitch
Sovereign Z5930 63" diameter 31" pitch

00:00 Intro and getting ready
00:45 Running through the propellors
02:51 Static Thrust measuring set up
06:39 First startup
09:19 First run with Lang LA10
10:07 Second run with Lang LA10
11:04 Changing the Propellor
12:41 Second Startup
14:10 First run with Sovereign Z5930
15:03 Second run with Sovereign Z5930
16:08 Cool down and debrief
18:44 Outro and clear up

My guess of 200 pounds was based on an old formula I found a while ago. Turns out it was fairly accurate! Static RPM and thrust are only a rough indication for a suitable propeller; the prop will unload as airspeed increases which is why the Sovereign prop coarser than the Lang was so good in flight (allegedly).

A shame the Flottorp didn't fit, I shall give it back the the owner as it's just on loan.

Music: 'Hammock Fight' by Kevin McLeod Copyright Free

#flying for fun #aeronca #aeroncac2 #aeroncac3 #aeronica #airknocker #flyingbathtub #douglasdc3 #douglas c47 #spitfire #hurricane #worldwar2 #ww2 #ww1 #airport #airstrip #automobileassociation #rac #aa #vintagesportscarclub #vintageaircraft #vintageaeroplane #vintageairplane #aeroplane #plane #flying #aerodrome #england #praga #oldengine #microlight #cornwall #thrustertst #vauxhall1440 #vauxhall #airplane #magneto #lathe