All-metal version of Bristol F2b...

[Lufbery]

All,

According to Jane's Fighting Aircraft of World War I (a 1990 reprint of an original 1919 publication), Bristol created a all-metal version of the F2b fighter. I don't have the book with me right now (I'm at work), but I think it was called the MRI. The wings were slightly larger and unstaggered, and there were various other small changes to the standard F2b design, but the biggest is that the entire plane was made of metal -- no wood or fabric at all. The interesting thing is that metal the plane was only 50 lbs. heavier than the wood and fabric version. Performance was slightly different, but that seemed to be more a matter of different engines (and probably even different propeller pitch) than differences in the structure.

So, I have two questions:

(1) Has anyone else heard about this plane? If so, are there more pictures available than just the side view in the Jane's book?

(2) Why is it that the all-metal version is only slightly heavier than the wood and fabric version? I'd think the weight difference would be much more than 50 lbs.

Regards,

To question (1)

There´s quite some information available on this plane. Good information for example in:

Jack M. Bruce, Warplanes of the first World War, Fighters vol 1, MacDonald, London 1965, p 107 to 110

Also the same authors " British Aeroplanes 1914-1918" by Putnam

Barnes, CH: Bristol Aircraft since 1910, Putnam, London 1964/1988

Photos and 3views of this aircraft at least in the Barnes and the Bruce "Fighters" book.

And the aircraft was conceptually similar, but not really a metal version of the F 2B. First flew with wooden wings BTW.

To question (2)

Not so strange. Look also on the Junkers D I, which used a rather complex structure, but (at 835 kg) was around 20 kg/40 lb lighter than the similar in concept Fokker V 21/23 monoplanes.

A metal structure, if carefully laid out, is not necessarily heavier. That´s a tendency you can already find in the very early metal designs. BTW, according to the Barnes book, the MR 1 was actually also marginally lighter than an F 2B with the same powerplant (1700 vs. 1740 lb).

Volker

And just to add one more point, the wings actually were fabric covered both in the early wooden and later metal version, while the fuselage was trulay an all metal affair

Volker

[Lufbery]

And just to add one more point, the wings actually were fabric covered both in the early wooden and later metal version, while the fuselage was trulay an all metal affair

Aha! That might explain why some of the extra weight that I was expecting wasn't there.

Thanks for the info and the references. I'm going to see if I can get my local library to find copies. BTW, did the lower wing carry through under the fuselage like on the F2B?

Regards,