P51/P80 aerodynamic test

Are those ‘sideways’ models on little turntables? Something to do with pitch? Very interesting – can anyone point me at the story behind these, Please?

Thanks,

Matt

Thanks John!

Well I live and learn. Would still be interested in what they were up to – beyond putting these in high velocity zones. As I say, what you”d demonstrate about a full size aircraft would limited, to say the least.

Please can you pass on the source of these? I am putting together a book on aerodynamic history and if these whole-aircraft (as opposed to semi span) tests are explained anywhere it would be of great interest to me.

Thanks again – and the OP and Sabrejet. I stand corrected – but baffled. The horizontally mounted one bottom left makes sense, but the sideways P-80 still doesn’t.

A few more related photos:

Sorry, I had seen the half model and wing sections before, and read a lot of the reports and memoranda arising from the work. With respect I do know about this research, my first post even describes it. I hadn’t come across full models before, and was/am dubious as to the value of such an arrangement bearing in mind the asymmetry that would be the immediate effect of anchoring the model by one distorted wing tip (as opposed to the thrust axis) in a flow of widely differing velocities spanwise across the model. A semi-span would appear much more useful.

When you add that the model appears illuminated differently to everything around it, you can see why I was and still am a bit suspicious as to whether a spot of creativity hasn’t crept into what has become the record. It won’t be the first time. Of course, if you can point me at the research papers, they are nearly all on line these days.. not being ‘funny’, genuinely interested ( this is my ‘thing’).

Yeah, there is no photoshop about it. The NACA used a number of Mustangs, for several years even after WWII, testing numerous experimental wing airfoils and aircraft designs, including that of the Bell X-1.

The Mustangs still flying today that served with the NACA (forerunner to NASA) are the Cavalier-prototype P-51D-5-NA 44-13257 (N51DL) owned by the Lindsay family, the P-51D-25-NT 44-84864 (N4223A) owned by the Coutches family, the P-51D-25-NT 44-84900 (N51YZ) owned by Bill Allmon, and the P-51H-5-NA 44-64415 (N49WB) owned by the Whittington family. Both the XP-82 under restoration to fly by Tom Reilly and the F-82E under restoration to fly by Pat Harker, are also both former NACA birds.

Bill Allmon’s P-51D is the only one flying today in its original NACA markings (NACA 127) and is filled with original NACA modifications and equipment. Pat Harker’s F-82E will also be finished in its original NACA markings when completed.

The Lindsay family Cavalier Mustang, 44-13257 (N51DL), was one of the earliest P-51D’s produced, and became NACA 108. The NACA was the first to design/develop the taller extended tail fin cap, which was fitted to all of their D-models (as well as at least one B-model that they had). With 44-13257 having had this modification, and being used as the prototype by Trans-Florida Aviation, the original NACA extended tail fin cap was copied and used on their Cavalier Mustangs. (The NACA would also influence the incorporation of a taller tail fin cap on the P-51H.)

The P-51D-5-NA 44-14017 that was used by the Navy for Mustang carrier trials in November 1944 also went to the NACA, following the trials, and became NACA 102.

I think the P-51 (not ‘P51’) concerned is still airworthy Stateside. Other pictures (many tests done on this P-51D) are around of similar tests on the same aircraft, using full model, half model, and various wing forms.

Nothing fake about any of it.

Not convinced.. yet. Semispans were flown, yes – as here; http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050019378.pdf

Perhaps original???
http://www.sim-outhouse.com/sohforums/showthread.php?55310-New-P-51D-Mustang-Little-Friends/page8

Photoshopped, but whoever did it forgot the shadows – on the top half of the model, but underneath everything else. It will be a picture from the NACA experiment where they placed a small vertical aerofoil, essentially a ‘vane’ at a point above the wing known to go locally supersonic, to see how it behaved. A simple way to explore areas over Mach 1 with a readily available subsonic vehicle. The small foil has been replaced in the image with a P-80. Not sure why.