Propeller ID: 3.7m diameter 4-blader

[jasong]

Hi Everyone,

I'm trying to identify possible aircraft for a cut-down four-blader that has been sanded and revarnished (not by me) which make the hub stampings very difficult to read, but appear as follows:

AD 555
LEFT HAND
75HP RENAULT
D3744 P2680

The 75HP Renault does not appear to have been a widely-used engine, with scarce references mostly focussed on 70HP and 80HP Renault engines.

At 3.744 metres, it would have been a very impressive prop. Such a shame it's been cut down.

Any thoughts? I've attached a photo of the hub stampings. Unfortunately I don't have anything else to go on.

Cheers,

Jason

[Dbahnson]

"AD555" was a two bladed prop used for a Clerget engine, so that doesn't fit. I can't really read the stamped numbers. There is a listing for "AD 532" which is a left hand tractor 4-blade with a Renault 75HP engine for the BE2c. At this point I'm guessing that's the most likely match, although I don't have the data for the diameter and pitch on that model to see if it matches yours.

Stamped horsepower often doesn't match exactly what is now listed as horsepower for a specific engine.

[Bob Gardner]

Hello Jason,

Good to hear from you again!

Another possible interpretation of the remains of the markings on your hub is:
AD535
D2744
P2600

These data are for a Standard Prop (ie; authorised by the Air Board) for a 75hp Renault engine for the early BE2C.

AD indicates that it was originally a design of the Air Department of the RNAS, but still extant in the 1918 list of Air Board numbers that I have.

With kind regards,

Bob

[jasong]

Thanks Dave and Bob. Hope you're both well.

You could be right about it being 2.744m rather than 3.744m Bob, in which case a BE2c is a perfect fit. A four-blader that big would be extraordinary. It's just so difficult to read the stampings.

I really appreciate your insights and expertise.

Cheers,

Jason

[Bob Gardner]

I'm delighted to be of help, particularly to an Australian, and even to an American!

With kind regards,

Bob

[Bob Gardner]

Jason,

Remind me, for I grow ever more slow of brain. Did I send you a complete set of my books recently?

Were they up to scratch?

With kind regards,

Bob

[Dbahnson]

Another possible interpretation of the remains of the markings on your hub is:
AD535
D2744
P2600

These data are for a Standard Prop (ie; authorised by the Air Board) for a 75hp Renault engine for the early BE2C.

AD indicates that it was originally a design of the Air Department of the RNAS, but still extant in the 1918 list of Air Board numbers that I have.

With kind regards,

Bob

Bob, do you mean AD 532? I have that listed as a 4-blade LHT for a Renault, but I have AD 535 listed for a Fiat engine.

[Bob Gardner]

Greetings Dave,

Confusingly there are two entries for AD532 in the Air Board list of 1918 that I use.

Firstly, AD532 for a 75hp Renault for the BE2C aircraft. This is not listed as a Standard Prop

Secondly, AD532 is also listed for a 250hp FIAT fitted to the front nacelle of a R23 RN Airship.

Neither listing shows any dimensions, nor are they listed as Standard props. I assume this is a clerical error by an Air Board clerk, who may perhaps have been day-dreaming about his girl friend etc.

The drg number AD535 is much more convincing.

With kind regards,

Bob

[jasong]

Hi Bob,

Nothing wrong with your memory.

Yes, I did buy a set of books from you recently - I think I now have all of your propellor books. They are a great reference.

Cheers,

Jason

[Bob Gardner]

Thanks Jason,

Now that you have the reference books we can enrol you as a forum expert!

With kind regards,

Bob