No, not a monoplane.

Lawson C-2 or L-4 perhaps

Not either of those.

Clue 3. Water cooled V12 engine.

Thanks for the clues. I believe the American Built DH4 was fitted with the Liberty Engine which was a water cooled V12.

Loening OA-1A ??

It's not the best of photos to pick up clues from, is it?

Looking at the control column, there appears to be a bicycle type brake lever attached to it which might support MReyn24050's suggestion of a DH4 as they had them.

And are those two round objects in the lower right of the picture part of an early oxygen supply system?

Did the Mail Carriers have to fly that high to avoid mountainous terrain?

Not a DH4 or a Loening OA-1A .

Agreed, the pic could be better but is the best my scanner can reproduce.

Clue 4. Engine is a 435hp Curtiss, and the aircraft is made by a company name starts with B.

then perhaps it is a Boeing PW-9, which had a Curtiss D-12 engine 435 H.P.

It is the Boeing PW-9.

That was a difficult one Henry. The only cockpit photograph of that aircraft I have seen is in the Putnam's Book on Boeing Aircraft and to be honest it looked nothing like that. Without your clues I would have been lost.

Here is a nice easy one. A little small, for which I apologise, but then you do not want it too easy.

http://i25.photobucket.com/albums/c6...t/cockpit5.jpg

MReyn24050: I scanned that cockpit view from Year by Year: 75 years Of Boeing History: 1916-1991.
Compiled and published by Boeing.

Henry

Please, I was not doubting you for one minute. The photograph in the Putnam book was no better than the one you scanned and did not show the area your picture did. It did state however that the main intrument panel was very narrow. It was an interesting challenge.

Has to be the `Gladiator`..............

Well done Sycamore. Said it was easy. Over to you for the next one.

If I may interrupt....

http://i20.photobucket.com/albums/b2...r/P9270240.jpg

Pitts S-1 G-AZPH ??

:mad: me that was quick!!

Yes its a Pitts. I don't know the reg. but its hanging up, inverted, from the ceiling in the Science Museum.

G-AZPH Pitts Special
http://aeroflt.users.netlink.co.uk/m...Museum%208.jpg

Next up then ....

http://img.photobucket.com/albums/v2...ying/pilot.jpg

Spaceship One. Pilot is Dave Binnie, I think.