Please help!

[pmdec]

Hi,

Somebody sent me pics of a prop found in Algeria. From the size and shape, I do think it is post WW2, probably from the 50' for a small aircraft fitted with a 90 to 120 HP engine.
I can't see any marking but the owner told me he can read on a blade root:
DES 401
SER 9541
ATO 710
So, I think it is not French but probably English or American.

I have found this post on the forum with "same kind" of markings and a compatible shape: http://woodenpropeller.com/forumvB/s...ead.php?t=1802 but the tips are cut so it is impossible to telle if the sheatings have the same shape.
By the way, what is the meaning of the letters ATO?

Diameter: 177 cm (69.7")

Regards,
PM

[Dbahnson]

I think the letters are "ATC", not "ATO" and are standard markings on U.S. built propellers. It stands for "Approved Type Certificate", and sometimes is just abbreviated "TC" followed by a number. I won't be at my other house until tomorrow but I'll see if I can match it to a known design at that time.

Any chance that the "401" is actually "491". If so it would match the Gardner propeller you linked above, and would appear on this page.

I should have some more information about that Type Certificate tomorrow. I suspect that the design applies to a number of different aircraft, mostly WW2 era trainers.

[Dbahnson]

PM,

Here's a scan of the propeller listings for U.S. manufactured props, so I think yours is Gardner model number 491. The footnote indicates that the type certificate expired in March 1957, which at least implies that it was manufactured some time before that date.

[pmdec]

Hi,

A big THANK YOU from the prop owner. All seems right with the 491: Here are some dimensions the owner sent me:
Diameter 177 cm = 69-11/16" vs 69-8/16" diff 3/16"
Hub thickness : 84 mm = 3-15/16" exact
Bolt circle : 110 mm = 4-21/64" vs 4-24/64" diff 3/16".

A pity the prop has been stripped and "protected"...

Regards,
PM

[Dbahnson]

A pity the prop has been stripped and "protected"...

Regards,
PM

Yeah, as always you wish that no one ever tried to "improve" them, but in this case I think even in original condition this one wouldn't be worth all that much anyway. It's just not that particularly rare or unusual, even in original condition.