Lockheed XPB-3 / XFM-2 Long-Range, Multi-Place Escort Fighter

[Pioneer]

Lockheed XPB-3 / XFM-2 Long-Range, Multi-Place Escort Fighter


Hello gents

I was reading about the Bell XFM-1 Airacuda ‘Long-range, Multi-place Escort Fighter’ design. In the text it said that Lockheed also submitted a design to the 1936 USAAC requirement. Lockheed’s design was the XPB-3 / XFM-2.
I have not been able to find anything on this design in books or on the web!
Does anyone know or have anything on it in the way of specs /tech data, drawings, 3-view drawings???

Regards
Pioneer

 

[elmayerle]

There was an article on the Neptune that had a few pictures of the XPB-3/XFM-2 mockup showing nose similarities to the Neptune. I believe the article was in an old issue of Wings/Airpower.

 

[lark]

Lockheed was awarded a study contract for a multiplace fighter
with designation XFM-2 and based on the Electra transport.
More conventional than the Bell XFM-1 design Lockheed's entry was also powered by two Allison turbosupercharged V-1710
tractor engines.
The mockup mounted a 37mm cannon in a nose turret and a
second one in a top turret.

So far : "Cobra! Bell Aircraft Corporation 1934-1946"
Birch Matthews - Schiffer

(no 3-views)

 

[Jos Heyman]

There was an article on the Neptune that had a few pictures of the XPB-3/XFM-2 mockup showing nose similarities to the Neptune. I believe the article was in an old issue of Wings/Airpower.

OK, so it took a while, but I only just stumbled on this yesterday in a search.
The article was in Airpower of March 1989, Vol. 19, no. 2, page 16. Scan attached courtesy my friend John Lewis.

 

[Stargazer]

Oh, I remember that article now.
Did you notice how the captions consistently get the designation XFM-2 wrong? They keep calling it an "AFM-2" which of course in totally wrong. The Lockheed Model 11 was the FM-2 (Fighter Multiplace, Type 2) just as the Bell Airacuda was the XFM-1 (Fighter Multiplace, Type 1).

 

[XP67_Moonbat]

Seems as good a place as any for this. From War Eagle Air Museum, here's the current newsletter with a feature article on the Bell XFM-1 Airacuda:
http://www.war-eagles-air-museum.com/newsletters/weam_newsletter_2011-4.pdf

The XFM-2 does get a mention in the article.

 

[airman]

The history of XFM-2 , later, prototype of Loocked Harpoon seems similar to Dornier 29 ( bi-engine fighter project of Luftwaffe) produced later like Do-17z

 

[lark]

In fact the PV-2 Harpoon stemmed from the PV-1 Ventura of which it was a much modified
successor. Both planes found their origings in the Lockheed Model 18.

The Dornier 29 project (1934 ) was a competitor of the Me 110. A zerstörer type aircraft.
Not quite a long-range fighter.

The American long range multi seat fighter concept was in fact a class on it's own.
One of the earliest proposals for this idea was a variant of the Martin B-10 designed +-1934.
But this concept remained on the drawing board.

To my chagrin I found no further info about the Martin proposal.

 

[Jos Heyman]

How far do you take these relationships? As we all well know, Lockheed liked the multiple fin design and took it from the Electra 10 all the way to the Super Constellation. With a little bit of imagination you can see in tyhe FM-2 (or Lockheed 11) an embryo of the Constellation. Just makes me wonder how many other designs like that- that we have not discovered yet - there were.

 

[Stargazer]

With a little bit of imagination you can see in the FM-2 (or Lockheed 11) an embryo of the Constellation.

Quite definitely. The Model 11 very much prefigures the later Model 44 Excalibur, which itself was the first step towards the Constellation.

 

[overscan (PaulMM)]

XPB-3 was the early designation (Pursuit, Biplace) for CP 604 designs which was altered to XFM-1/-2 (Fighter, Multiplace) before production.

 

[hesham]

From Aerei Nella Story 4-5/2009.

 

[hesham]

There was an article on the Neptune that had a few pictures of the XPB-3/XFM-2 mockup showing nose similarities to the Neptune. I believe the article was in an old issue of Wings/Airpower.

OK, so it took a while, but I only just stumbled on this yesterday in a search.
The article was in Airpower of March 1989, Vol. 19, no. 2, page 16. Scan attached courtesy my friend John Lewis.

A clearer view to it,

please can anyone make a 3-view to it,or tell us where to get like this,in
any source ?,and thanks.

 

[jcf]

Drawings from Lockheed reports:
No. 101, Preliminary Specification, March 1936.
No. 812, Wind Tunnel Tests of a One Eleventh Scale Model of Lockheed XFM-2, Feb 1936.
No. 817, Analysis of Armament, March 1936.

 

[jcf]

Wing airfoil sections:
Root NACA 23016, Tip NACA 23008

Wing Dimensions
Area: 781.3 sq. ft.
Span: 954" (79' 4")
Root chord: 186.1"
Tip chord: 53"
Taper ratio: 3.51
Incidence: +2°
Dihedral: 6° 15' (at chord line)
Sweepback (L.E.): 5°
Max. rib spacing: 18"
Shear web/spar locations:
front SW 7% of chord, main spar 33 1/3%, rear SW 73% (bottom contour).

 

[jcf]

Horizontal Tail Surfaces
Area: 163.6 sq. ft.
Span: 336" (28')
Max. Chord: 90"
Normal setting: +3°

Vertical Tail Surfaces
Fin: 33.6 sq.ft (total), normal setting 0°.
Rudder: 35.6 sq. ft. (total), angular movement of 35° right and left.
Mounted 144" outboard of aircraft centerline

 

[jcf]

Fuselage
Max. height: 98.5"
Max. width: 83.25"

Nacelles
Mounted on the wing leading edge, 107"either side from the centerline of the aircraft.

Alighting Gear
Main: tread 214" (17' 10"); 45" diameter 15.00 X 16 tires and wheels.
Nose: 32" diameter 11.00 X 12 tire and wheel.

 

[jcf]

Report No. 817, Armament Analysis

 

[Antonio]

Exceptional contribution. Many thanks sir.

 

[jcf]

Exceptional contribution. Many thanks sir.

You're welcome.

 

[hesham]

Brilliant,thank you dear Jcf.

 

[lark]

Fuselage
Max. height: 98.5"
Max. width: 83.25"

Nacelles
Mounted on the wing leading edge, 107"either side from the centerline of the aircraft.

Alighting Gear
Main: tread 214" (17' 10"); 45" diameter 15.00 X 16 tires and wheels.
Nose: 32" diameter 11.00 X 12 tire and wheel.

After years of searching ,at last an answer...
Thanks so much JCF

 

[lark]

After years of searching , at last an answer
Thanks so much JCF

 

[Aeroweanie]

Wing airfoil sections:
Root NACA 23016, Tip NACA 23008

Wing Dimensions
Area: 781.3 sq. ft.
Span: 954" (79' 4")
Root chord: 186.1"
Tip chord: 53"
Taper ratio: 3.51
Incidence: +2°
Dihedral: 6° 15' (at chord line)
Sweepback (L.E.): 5°
Max. rib spacing: 18"
Shear web/spar locations:
front SW 7% of chord, main spar 33 1/3%, rear SW 73% (bottom contour).

Can you also upload a copy of No. 812, Wind Tunnel Tests of a One Eleventh Scale Model of Lockheed XFM-2, Feb 1936?