M FARMAN Wooden propeller

[pmdec]

No, I don't think that would make sense because sooner or later someone would put the right number on an airplane without looking at the thread direction. It obviously would be discovered when it was started (but likely sooner) as the plane backed up as soon the throttle was advanced.

Using a different drawing number makes much more sense, even if it's just the next in number sequence.

Hi,
I think the same.
But each of those two pics shows a RHP prop:
https://pbs.twimg.com/media/C-C5pD_XoAAmKDP.jpg
https://upload.wikimedia.org/wikiped...thorn_MF11.jpg
The Utahraptor prop seems to be stamped:
IPC
DG 2303
HP 80 REN
M FARMAN
B 24722
and the IPC 2303 in books is reported as a LHP for M Farman fitted with a 80 HP Renault...

So ... ???

Regards,
PM

[Dbahnson]

It's a mystery to me, PM. Both of the two propellers I owned are stamped for the Bristol F2b with a Rolls Royce engine and both have the same diameter and pitch stamped on them. One is left hand and one is right hand and I know it's not a reversed photo because I had them side-by-side at one point and they were clearly opposite rotation.

How do you tell the direction of rotation in those photos? I can't see it clearly enough to know . . .

[pmdec]

.../...
How do you tell the direction of rotation in those photos? I can't see it clearly enough to know . . .

Hi, it is more an impression that a certitude, but:
- it seems that the straight edge is going to the farther side of the hub, so it is the trailing edge,
- from their shape, the 3 props visible on the pics are probably all Chauvière which had straight and aligned trailing edges and convexe leading edges. So they are clockwise rotating when viewing from the rear.

I don't think there were straight leading edge and convexe trailing edge props fitted on Farman in this era: the only props whith this shape I know about are French "Rapid" and "Ratier" propellers and:
- Rapid were no more made after 1914,
- Ratier didn't made any prop for Farman.

Look at the pic showing a Chauvière and a Ratier (exactly the same shape that Rapid): On the pic, they are rotating the same way because the Chauvière has it front side shown (it is a RHT) and the Ratier has its rear side shown (it is a LHP).

Regards,
PM