Identity of Prop (boss)

[Tony Kearns]

Good evening all,
A visitor to the Irish Air Corps Museum and Heritage Centre showed us details of a boss which he has (it always makes me sad when the propeller is cut to the boss) It has listed the following on the side :
27.5 Rolls Royce (or it may be 275)
D280, P3600, AB 686 RH and with 2751 on the front.
Any help is much appreciated.

Regards
Tony Kearns

[Dbahnson]

It's not listed in my reference material, but drawing AB 685 had two versions with slightly different diameter and pitch used on a DH4 with the Rolls Royce Eagle and Eagle 8 engine. Both were 4 bladed left hand tractor versions, so it's possible that this was a right hand version of one of those. Is it 4 blade or two?

[Tony Kearns]

Great many thanks. The owner states it is a two blade, but he did not bring it into the museum.
It was found at Ballincollig, Co. Cork, there was a barracks and a landing field nearby used by the RFC/RAF during the war of independence. I was not aware that DH4 was used during that period but it seems to fit. I am hoping that the boss would be donated to the museum and then we can photograph it .
Thanks as always for your help now and on previous occasions.
Regards
Tony K

[Bob Gardner]

Greetings Tony,

Good to hear from you again.

I have added several more lines of data about AB686 to my database. I add them constantly, with much of the info coming from this website. AB685 and AB686 appear to be identical. The eight props I have recorded had diameters from 2800mm to 2900mm and pitches from 3340-3600mm. Two of the eight were made by Boulton Paul. They were all four bladed.

If you have several wooden props in your museum, could you send me a list of the data on them, so I might add them to my databases? I would be most grateful.

With kind regards,

Bob