NACA YP-47M Propeller Testing ...

[Mark Allen M]

"The appearance of the V-1 flying bomb, jet fighters such as the Messerschmitt Me 262, and rocket fighters such as the Messerschmitt Me 163 Komet led Republic to begin development of a high-speed variant of the Thunderbolt. Four P-47D-27-RE's were modified with a 2,800 hp R-2800-57C engine with a CH-5 supercharger and the dive brakes of the P-47D-30 as YP-47M's. An improved 13' Curtiss Electric C542S-B40 propeller was fitted, and changes were made to increase speed. These improvements raised the top speed to 473 mph. In September 1944, the last 130 aircraft from the original P-47D-30-RE order were converted into an order for a production version of the YP-47M as the P-47M-1-RE. Deliveries began in December 1944, though engine problems delayed their combat debut until a few weeks before the end of the war in Europe".

Yanks Air Museum's Thunderbolt is a YP-47M-1.
https://yanksair.org/exhibition/republi ... underbolt/

Below are propeller wind tunnel tests conducted on a YP-47M.










PROPELLER BLADES USED ON P-47 AIRPLANE DURING PROPELLER TESTS

[Mark Allen M]

P-47's Big radial engine.

[Noha307]

So, one of the cool things is that NASA has uploaded a bunch of old wartime reports to the NASA Technical Reports Server, or NTRS. When I saw this post I figured I'd give it a quick search for "YP-47M" and, lo and behold, there are indeed at least five propeller test reports available online:

• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading I: Aeroproducts H20C-162-X11M2 Four-Blade Propeller
• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading II: Curtiss 838-1C2-18R1 Four-Blade Propeller
• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading III - missing
• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading IV: Curtiss 732-1C2-0 Four-Blade Propeller
• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading V: Curtiss 836-14C2-18R1 Four-Blade Propeller
• Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading VI: Hamilton Standard 6507A-2 Four and Three-Blade Propellers

Mark, if you don't mind me asking, where specifically did you source these pictures from?

[quemerford]

Lovely shots Mark: many thanks for posting.

[Mark Allen M]

All the photos posted came from the National Archives.

[mike furline]

Mark, if you don't mind me asking, where specifically did you source these pictures from?

Record Group 255, lots of cool photos not just P-47's. https://catalog.archives.gov/search?q=p ... Number=255

https://catalog.archives.gov/id/354761740
https://catalog.archives.gov/id/354767424

[Mark Allen M]

Yep! He’s found them. A bit tricky to dig them up at first. Had to put some real basic words in the search box. But plenty of very interesting NACA stuff in there.

[mike furline]

Yep! He’s found them. A bit tricky to dig them up at first. Had to put some real basic words in the search box. But plenty of very interesting NACA stuff in there.

Oh geez, I've had them for months.

[Mark Allen M]

Yep! He’s found them. A bit tricky to dig them up at first. Had to put some real basic words in the search box. But plenty of very interesting NACA stuff in there.

Oh geez, I've had them for months.

Calm down! That was mean’t to explain how I found them. Had nothing to do with how you searched for them.

[quemerford]

Well my dad found them first!

[marine air]

There's one YP-47M-1 owned and displayed at Yanks Air Museum. It was once restored to flying condition and is in nice shape.

[quemerford]

There's one YP-47M-1 owned and displayed at Yanks Air Museum. It was once restored to flying condition and is in nice shape.

There's a link to YAM in Mark's post.