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Originally Posted by Soren So you don't think that a 6.7 G limit load factor at just 9,500 lbs is rather low ?? |
No, it is apparently higher than the standard British requirement for aircraft (5.33 gs, see below). Also, note the following F-16 g limits between normal and loaded. I cannot verify these numbers but they are typical and the source seems knowledgable.
F-16 g limits
maximum ordnance 20,450 lb (9276 kg) for 5-g maneuver limit or 11,950 lb (5421 kg) for 9-g maneuver limit.
You may also note below that the gs specified on the P-51D was per AAF standards. I suspect you would find similar charts with similar numbers on the P-38, P-47, et. al.
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Do you have any proof to back up this claim davparlr ?
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“A new, lightweight, NA-105 design was offered in January, 1943, and a July 20 contract was called for five prototypes. Using load factors reduced to British standards,…”. This was the criterion for the XP-51F. “The lessons learned from these machines were incorporated in the last production model, the P-51H, …”
American Combat Planes, Ray Wagner, 1968
P-51H
The original NA-73 had been built to the USAAF acceleration standard of 8.33 g (82 m/s²), which made it stronger but considerably heavier than if it had been designed for the British standard of 5.33 g (52 m/s²). Both the USAAF and the RAF was interested in lightening the plane to be more in line with the Spitfire, which was expected to boost its performance significantly.
P-51 Mustang - Wikipedia, the free encyclopedia
“The original NA-73 had been designed to higher load factors than the British Air Purchasing Commission had required. As a result, the structure of the Mustang was considerably heavier than that of the Spitfire, and it was felt that a considerable improvement in performance might be obtained if structural weight could be reduced. Edgar Schmued that traveled to England and had inspected the Supermarine factory, and he had also studied captured Messerchmitt and Focke-Wulf fighters. In January of 1943, North American Aviation suggested to the USAAF that they build a special lightweight version of the Mustang. It was agreed that a thorough redesign would be carried out, mainly to reduce weight but also to simplify systems, improve maintenance, and enhance performance without changing the engine. The new Mustang was to be designed to a combination of optimal British and American strength requirements, but mainly to those laid down in British Air Publication 970.
The project was given the company designation NA-105. Two prototypes were ordered under the designation XP-51F…”
North American XP-51F, G, J Mustang
[QUOTE}Dig deeper davparlr...[/quote]
I have not uncovered a significant problem with P-51 wings, but my knowledge is limited. However, pilot quickly identify aircraft that threaten their lives and react accordingly. I have never seen P-51 pilots complain about the safety of the planes, or scurry to get out of the P-51 to find another aircraft, or not want to be assigned to the P-51. The opposite is more the norm with pilots wanting to stay with, or be assigned to, the P-51.
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Well who wouldn't have with a 12 to 1 superiority in numbers ?
In any case 12 G was never reached by any fighter in WW2...
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No disagreement here.
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I can easily justify it - Speed is life. Just ask Spitfire pilots who served over the channel in 42.
Also just take look at the plane, its quite obvious that its design is purely and entirely speed orientated - the wing and horizontal stabilizer amongst other things having undergone major alterations compared to the B/C/D.
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While the design changes you mention are true, there is no evidence that the P-51H would be less capable in manuevering than the P-51D. It did possess a lower wing loading, higher power to weight ratio, and better climb capability than the P-51D. All which says it could be a formidable dogfigther.
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The chart above is the "Absolute" limit of the a/c at that specific setting, just like any other performance and endurance specification in the manual.
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This is not correct. The page you show is from a manual called T.O. No. 1F-51D-1, or the dash one, as called by pilots. It defines normal and emergency procedures for aircraft (an operators manual). The g levels noted are normal operating levels, not "absolute levels". The AF does not want pilots to operate the aircraft next to the "absolute" limit, which they would do if the absolute limits were provided to them. Typically, all limits in the manual have safety margins built in, be it gs or rpm or speed.
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Yeah and hadn't it been for all the delays caused by the RLM, the Ta-152 would've probably been in service with frontline units as early as June 1944.
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The NA-105 which led to the XP-51F,G, and H, was contracted for prototype development in July, 1943, with the XP-51F flying Feb. 14, 1944. I am sure that if there had been a need, the H could have been out much earlier.
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A) Addressed ? How ? We're talking WW2 fighters here davparlr, not Jet fighters.
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I believe your comment was about 1 to 1 thrust to weight ratio preventing the need for a high aspect wing. My comment was that 1 to 1 thrust to weight did not occur intil the F-15 came out in the early 70s. There were many aircraft before that without 1 to 1 thrust to weight and did not use high aspect ration wings.
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C) Perhaps not computer controlled but even soon after WW2, when jets appeared, different kinds of slats and various other high lift devices were being used on low AR a/c in order to reduce the huge drag penalty such a/c suffer from in maneuvers. Also worthy of note is the obsession with speed which occured in fighter design just after WW2, with wings on aircraft growing ever smaller, just for sake of extra speed - The MIG-21 and F-104 are clear examples of this, in an era where maneuverability took a back seat to pure speed.
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I don't really know enough about slat usage, especially manuevering slats, to argue this point.
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D) Indeed, but it is infact a huge reason to why the F-22 has such a low AR wing.
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This I disagree with this. The YF-23, which the technical preference of the AF, was faster, more stealty and met all the manuevering requirements of the proposal without thrust vectoring and it also has a very low wing ratio. And of course we could talk about he F-15, F-14, etc.
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E) 8 G's mentioned where ?? If you're talking about the P-51H it could most likely only take around 6 G before its wing starts dismantling itself from the fuselage. - not at all a pleasant thing.
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See comments on operational verses absolute gs and g levels of spitfire.
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Later high performance Spitfire's actually featured longer wings, either that or same span wings with different planforms and airfoils.
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Didn't do further research on this but I suspect no model of the Spitfire had a high aspect ratio wing.
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It takes both great wing and engine efficiency to reach the altitudes the Ta 152H did.
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Boy, the U-2 must be one hellacious dog fighter! Who needs the F-22. All you said is true about flying high but that doesn't translate into low altitude performance. There is always a trade-off between high and low altitude performance. Its really tough to made a airplane perform superlatively in both environments.
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And the Ta 152H-1 need not have feared the P-51H at any altitude..
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I have not seen any data you have submitted that supports that conclusion. All you have done is try to degrade the P-51H with marginal information. I have posted arguments with data that the P-51H configured equivalently with the Ta-152H-1 has a clear airspeed advantage, wing loading advantage, and power to weight advantage over the Ta-152H below 30,000 ft. I do understand, from other commenters that I feel are more open minded, that data exist that would strengthen you argument. I do hope it becomes available. Good data is always good to have.
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