ACCESS: Top Secret
- Jan 22, 2006
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Curtiss Light Bomber Proposal P-517 & P-517A. Report No. 21203. March 30,1946
They seem to look a lot like scaled up Blackhawk designs. Any info on the engines and location of the engines?pometablava said:Curtiss Light Bomber Proposal P-517 & P-517A. Report No. 21203. March 30,1946
Any ideas what competition this was meant for?
In 1945, the US Army Air Forces issued a requirement for a light bomber aircraft. In February of 1946, a design competition was announced based on the USAAF requirements.
On April 1, 1946, the Glenn L. Martin Company of Baltimore, Maryland proposed a straight-winged, six-seat attack bomber powered by two TG-110 turboprops and two I-40 turbojets. The aircraft promised a maximum speed of 505 mph, a cruising speed of 325 mph, and a combat radius of 800 miles. The Martin design won the competition, and was assigned the designation XA-45 in the attack series.
In the spring of 1946, the USAAF revised its requirement, calling for an aircraft with better performance for all-weather, close-support bombing. The revised characteristics called for a redesignation of the Martin design as XB-51. A fixed-price letter contract issued on May 23, 1946 called for two XB-51s, to be accompanied by wind tunnel models and mockups.
The military characteristics specified in 1945 and 1946 were revised yet again in early 1947. The XB-51 was now pictured as a low-altitude attack aircraft and the combat radius requirement was reduced.
seems to be a single jet engined design with some auxiliary rocket?
Didn't one of the iterations for the B-47 have a similar engine arrangement?
pometablava said:Well, I there was one iteration with engines in the back, right after the cockpit but I have nothing similar to this Curtiss design in my B-47 archive.
Possibly Evan or Orionblamblam can give some ideas?
As for my last post, please ignore my reference to the XB-51 and different design teams within Martin. I mentally swapped Martin for Curtiss when thinking of the designs. Duh, this is a Curtiss proposal model...
pometablava said:Thanks for the Model 448 drawing Scott, but the mistery is still unsolved. That Curtiss design has a unique engine layout ...
taildragger said:For a while in the late 40's there was enthusiasm, in the US industry anyway, for extremely small diameter jet engines that would be used in large numbers in aircraft. They would have given designers more freedom in installation (albeit with some added complexity) and overcome the low engine reliability of the day but, as I recall, the main motivation was a belief that microjets would be inherently more efficient for geometrical reasons. The reasoning seemed flawed to me but apparently elements of the industry bought into it - for a while.
Jemiba said:I think it's this:
Good find, the engines seem to be further aft, than in the model.