A REAL Mystery Plane Quiz

[JDK]

G'day folks,
Just found this picture on the NACA Langly pages (picture No.16) of 'Flying Boat Construction'.

The question is which flying boat? It's intreaguing, and I've a guess, but over to the site gurus...

http://grin.hq.nasa.gov/BROWSE/naca-larc_2.html

[seacue]

It looks like the wing for a model of the Boeing 314.

Probably being built for a model to be tested in Langley's very large low-speed wind tunnel.

There is a beautiful model of the 314 hanging in an American Airlines area at the Miami airport.

SC

[tharg]

Chaps...
Hate to disagree but the Boing 314 was developed in 1938 so unlikely NACA doing wind-tunnel testing in "circa 1944" unless Mr Boing was redesigning wing (possible nevertheless). Moreover, all snaps of 314 seem to display distinctly rounded wingtip - not squared-off shape shown in pic. Now, early Martin Mars seem to have said squared-off tip but photos are pretty hazy (and Mars was in development stage around '44). Will attempt to check old copies of JAWA to confirm.

[JDK]

Thanks Guys,
My guess was (IF it was a machine which got built!) it could only be the Mars, but it's still not quite right to me in some ways.

Shoul've said on my original post I wasn't being clever about this being a 'real mystery' Mr Seacue - just that I didn't know what it woz!

Cheers

James K

[Aerohack]

It all hangs on the accuracy or otherwise of the caption. If 'circa 1944' is right then it's probably too late for the Mars, which had been flying as a prototype since July 1942. The wing planform looks very much like that of the Convair 117/R3Y Tradewind, but the timescale and nacelle shape don't fit.

[Lu Zuckerman]

To: seacue

Bob Lanthier constructed the Boeing 314 model in Miami airport. He also constructed a model of a Douglas DC, 2/3 that is suspended in the airport not too far from the B-314. Bob also constructs full-scale replicas of famous WW 2 aircraft to include the Mosquito, the Spitfire and the Hurricane as well as other full-scale replicas of US aircraft from that same period.

:E :E

[Iron City]

So if it is 1944 (clothing of workers looks anbout right for that) and it isn't a Martin Mars could it be a Mariner or Marlin from Martin ? Being that Langley is closer to Martin's Baltimore home, hon, I'd bet on Martin product rather than Convair/Consolidated that would be tested at Ames.

[Tonkenna]

Don't know what the ac is, but the young lady was a bit ofa looker:)

Sorry thats very shallow

Tonks :)

[tharg]

Unless me sources are wrong, the Mariner and Marlin were twins so that puts them out of the frame. The Consolidated Vultee PB2Y-3 Coronado was briefly in the frame but, again, the timescale was wrong (entered service in 1938) and a three view drawing revealed the wing to be all wrong.
Mr A/hack - you are quite right in that the Mars had been flying since 1942 as a single prototype but, in Jan 1945, USN ordered an "improved version" which differed from the prototype in having a revised, longer hull and replaced the twin fins with a single 44ft high fin. When USN scaled down its order from 20 to 6 copies, (delivered in July 1945) Glenn Martin tried to push the monster as a cargo/passenger aircraft and also proposed a landplane using the Mars engines and wing.
The structural changes for the USN's 1945 copies would have changed the aerodynamics of the beast. I'm guessing here, but testing the new configuration for lateral control/rudder efficiency could be what they were setting up to put through the wind tunnel. So, my money's still on the Mars, chaps: the timing is close(-ish) "circa 1944" is pretty vague; and there were new bits to be checked and/or Martin might have been testing the "seaplane wing" for use on his landplane transport.

[Aerohack]

I have to agree that the wing planform and nacelle configuration is about right for the Martin XPB2M-1 Mars prototype or the final JRM-1 Mars, save for the tip, which appears not rounded enough. The XPB2M-1 seems to have had a Hoerner-style tip, which could look like that from the underside, I suppose. On the other hand, if that blueprint on the table is of the same aircraft, then the fin configuration doesn't fit either prototype or production Mars. It could have been an interim design. But it is not unlike the fin of the Hughes HK-1 ('Spruce Goose') and that wing shape is right. Hughes's chief designer Rae Hopper and aerdynamicist Carl Babbenger worked out of an office at NACA Langley in late 1943 while drawing up the HK-1's configuration. They tested hull shapes in the Hydrodynamics Dept's towing basin and wings in the low-turbulence wind-tunnel there. This one has only four nacelles, though...

[tharg]

Mr A/hack - I am not worthy! You have an eye for the shape of an aeroplane, sir and it is VERY perceptive. To test your ideas about the "Spruce Goose" I scanned in three-views of both JRM-1 Mars and Hughes HK-1 Hercules. Ran them into Photoshop and used Transform functions to match the perspective of original NACA photo and see how close each one came to the blueprint on bench (the presence of which I missed entirely - 2 out of 10 must try harder). The HK-1 matches almost every line - chine of hull, rear step, wing and fin profile. Cannot make the Mars match anywhere near that good. The rounded/squared-off wingtip is, I think, not a factor since, from study of many snaps of the Mars, the airfoil (Sp?) profile makes it seem both flat and round depending on the angle of photo.

So early design study for HK-1 I reckon it is - before the decision to fit her with eight monstrous four-row P&W Wasp radials, but after Mr Kaiser (the 'K' in HK-1) in 1941 switched his allegiance from Glenn Martin (wanting to build hundreds of Mars, which GM did not fancy at all) to Mr HH (wanting to build hundreds of Spruce - Spreece? - Geese). A curious hybrid of Mars and Goose… Moose maybe? Only anomaly/unknown factor remaining is whether the timing works. But your info on Hughes' designers Babbinger and Hopper working out of NACA seem to tie that up as well.

So, to quote Christopher Plummer's character in Guy Hamilton's Battle of Britain fillum, (on Ch5 next Thurs BTW), I reckon it's a case of,. "Foxtrot leader… break it off. Home… and tea. Well done everybody…"

Next..?
;)

[Aerohack]

Holmes and Watson, eh tharg? Nice work!

[JDK]

Well, chaps, a fine hypothesis. Also extras points for Tharg scanning in the profiles etc - I didn't think anyone would go to such lengths! I am honoured. Looks like Mr Seacue (and my humble self) will have to come up with harder brain teasers in future. Still there's lots of great questions out there.

Indeed "Time for tea..." (I always felt very sorry for the poor leader of those Heinkels with no 109s to help. Still that's what you get when you go round invading Poland...)

Cheers
James