Rotax 912… Beautiful Sound

[Piper J3]

A private airstrip near me is used by a radio control flying club. I was asked to fly the runway so the guys could get idea of speed for comparison. I didn’t look at IAS, but I guess probably 120 knots... A short video was taken with a cell phone, and what surprises me, is the sound of the engine. I expected the usual Rotax gearbox clatter but sounds more like a Rolls Royce Merlin…

Lodi AAGMC.mp4

drive.google.com

 

[pstraub]

A private airstrip near me is used by a radio control flying club. I was asked to fly the runway so the guys could get idea of speed for comparison. I didn’t look at IAS, but I guess probably 120 knots... A short video was taken with a cell phone, and what surprises me, is the sound of the engine. I expected the usual Rotax gearbox clatter but sounds more like a Rolls Royce Merlin…

Lodi AAGMC.mp4

drive.google.com

Sounds very healthy Jim, thanks for posting!!

 

[bobg56]

I agree, I had a cell phone video of a fly over that I did and to me it had that RR sound as well.

 

[wsquare]

The gear box "clatter" occurs mainly at idle / low rpm. When the gear box "dogs" are banging into each other, as the prop momentum and engine torque dynamics/harmonics are interacting in an inefficient manner. Once the dogs are loaded, due to application of throttle, and increasing rpm, the gear box runs quieter.

 

[NinerBikes]

Most of the noise you'll hear on passing by is from the prop doing 2100 -2200 rpm. This was taken by the wife with me flying over at about 2000 AGL at about 113 kts and 5250 rpm. You'll probably need ear buds to hear it clearly.