FLYBOYJ
"THE GREAT GAZOO"
Not nitpicking but you did have Composite Groups in the AAF during WW2 where several different types of aircraft were operated at the squadron level within the group.
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
one Group would NOT fly mixed aircraft for long due to the two logistics chains.
Not nitpicking but you did have Composite Groups in the AAF during WW2 where several different types of aircraft were operated at the squadron level within the group.
Greg - composite groups were operated in one form or another throughout the war. I believe there were 8 or 9 of them, the most famous was the 509th Composite group, operated Silverplate B-29s and C-54s. The 342nd Composite Group operated for over 2 years and operated at least 4 different types of aircraft. 342nd Composite Group (USAAF). Composite groups operated in the post war and I believe there were a few operated during the Korean War.Hi guys,
I'm sure the composite groups were operated but, as stated above, not for long periods.
Hi,
So, that seems like a deliberate decision to operate a composite group for a specific reason, not an across-the-board haphazard mix of aircraft. I'm sure heavy bombers take many heavy spare parts and having some tramspoprts makes keeping everything running a LOT easier than waiting for somebody else to fly them in.
When I was in the Air Force at Ellsworth in South Dakota, we had a B-52 wing, but we also operated KC-135s and had two semi-permanent T-33s. The B-52 and KC-135 mix makes good sense, and the T-33s were not really often-used, but enough to see them every once in a while.
I'm not too sure about the mixed operation being difficult. Here is a clip of the Planes of Fame Airshow in 2012 with two P-51s (Merlin variety) and our P-38. They didn't seem to have any trouble. Two four-bladed Merlins and two three-bladed Allisons together. Of course, they weren't in a combat situation, either. But Steve Hinton (in the P-38) wasn't babying the Allisons.
I have seen I said in here that there is no way the XP-39 went 390 mph, but have seen no proof of same except for some various quoting of poorly-documented wind tunnel testing done on the machine either before or after the turbocharger was deleted. The posters don't bother to say. There is, however, some considerable second-tier sources that say otherwise.
There is a digitized NACA report (Engineer in Charge: A History of Langley Aeronautical Laboratory 1917 – 1958) which states that the XP-39 DID achieve 390 mph using 1,150 hp @ 20,000 feet. But, it did so at a gross weight of 5,550 lbs at takeoff.
URL: Engineer in charge .
.
It would be SO easy to position your static ports in spots that are low pressure areas at max speed AOA to gain optimistic airspeed readings. While this wouldn't survive rigorous testing (NACA), it could be used to favourably impress potential buyers evaluation pilots. Just the sort of stunt Larry Bell would be attracted to.in this time period it was quite common for manufacturers (and governments) to exaggerate performance claims.
Hi Old Jim,
Very true. The wartime "experts" never flew the plane with the ammunition completely expended.
They did the test in a wind tunnel after the war (in the 19770s) and it did, in fact, tumble.
A link: 20-Foot Spin Tunnel (645) Models and Tests N-Z - NasaCRgis
I was one of the participants in the 1970s P-39 tumbling study. And yes it was totally an unofficial and unfunded test. But now everyone involved is either retired or passed on, so no one can get in trouble, but it can be good lesson on how sometimes historic research gets done. At the time I was an aerodynamics engineer at Beech Aircraft involved in new aircraft development and as part of my job I did both flight testing and wind tunnel testing including many spin tunnel tests at Langley. I studied aviation history both as a hobby and to gain knowledge and data for my vocation of engineering. A friend of mine, who was also an aeronautical engineer and history buff, had been doing research on the P-39 stories of tumbling. He had gone thru the old Wright Field reports and noted that they had seen no tendency of the aircraft to tumble, but he also noted that the flight testing was all done with an equivalent full mass of ammunition in the nose and full fuel. He had interviewed several P-39 combat veterans and they had indicated to him that the tumbling occurred on the return from combat missions when the ammunition had been expended and fuel burned off. He asked me if I had at looked at the NACA P-39 spin tunnel test data? I told him yes, but only from the point of view of the effect of the door opening and of the pilot escape path. But I also informed him I had a spin tunnel test to do at NASA Langley in a few weeks and would ask see the P-39 test data while I was there. My NASA friends pulled the P-39 test file for me and the NACA spin tunnel test had been done at a request from the AAF which called out the test requirements. The AAF had only requested testing at full gross weight and that was all that was done. There was no sign of tumbling seen. Now one has to remember that in WWII the Langley tunnels were running 7 days a week, three shifts a day, so there was little time was for exploring outside the formal test request. During a coffee break in the spin tunnel conference room, I brought up the P-39 tumbling. The NASA engineers got interested and also read the file. Now in the 1970's, the offices, hallways, and conference room in the spin tunnel building all had old spin tunnel models hanging from the ceilings. Now it just so happened one of the models hanging in the conference room was the P-39. Also Jim Bowman, head of the spin tunnel at that time was in on the coffee break and mentioned that in WWII he had been an apprentice in the model shop where the P-39 model was constructed. Well as you probably know engineers and wind tunnel technicians are nothing but over aged little boys, thus a plan was formed to refurbish the P-39 model and test it in those other flight conditions. Of course this was all done on lunch hours and coffee breaks! A few check points were made at the gross weight loadings which repeated the original WWII tests. The model was then reballasted to simulate no nose ammunition and low fuel and retested. And with this loading the P-39 model would sometimes tumble.
As for the comment about what it doesn't show (not yours, Biff), what it clearly tells me is the dissimilar aircraft have no problems flying formation. Our fighters cruise to airshows and other public displays together routinely in formation, and they don't have any trouble. We have even had a P-47, P-38, and P-51 information with an F-22, and THEY didn't have any trouble with it, either.