North American Aviation XP-51F - "Mishandled Menace"

Would you like to see the North American Aviation XP-51F in game?
  • Yes, as a tech tree vehicle
  • Yes, as a premium vehicle
  • Yes, as an event vehicle
  • Yes, as a squadron vehicle
  • No, I would not like to see the XP-51F in game.

0 voters

If you support the addition of the XP-51F, would you also like to see it for the U.S. tech tree?
  • Yes, I would
  • No, I would not
  • I voted no on the first question

0 voters

XP-51F s/n 43-43334 is seen here in British markings with drop tanks and .50 caliber machine guns installed. Its position next to its sibling, XP-51F s/n 43-43333, and the Mustangs in the background imply the aircraft is still in the United States, which makes the new camouflage scheme somewhat puzzling. By the time it had been transferred to Britain, the XP-51F appears to have lost its armament.


Introduction

      The story of the North American Aviation P-51 Mustang is a story of collaboration between the United States and United Kingdom, producing one of the most vital fighters for Allied operations in Europe and arguably the best fighter of World War II. The P-51D (Mustang Mk.IV) has cemented itself as a legendary aircraft, but even its designers recognized that it had room for improvement. The continuation of the Mustang saga began with the “Lightweight Mustangs” - the NA-105 prototype aircraft. As the Mustang had begun, so too would it evolve, with collaboration between NAA and Supermarine producing the fastest Mustang variants ever. The ancestor to the P-51H was trialed not only by the USAF but by the Royal Air Force in the form of both the XP-51F and XP-51G. This is the story of how the Mustang reached its zenith - and why the RAF wasn’t interested in it at all.


TL;DR

  • High performance redesign of the venerable P-51
  • Lighter weight and aerodynamic redesigns provide increased performance
  • Reduced armament akin to the P-51C but with less ammo
  • Lower wing loading for more agility
  • Superior stalling characteristics
  • Large, high mounted canopy for better visibility


History

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      The history of the P-51 as a whole has further reading readily available, so its genesis does not require too much examination. The Mustang arose from Britain’s purchasing requirements for a new American fighter to supplement British equipment. Outsourcing production in this way would allow the RAF to take advantage of America’s excellent industry while being able to commit their home factories to existing designs like the Spitfire and Hurricane. However, none of the currently available (in the late 30’s) aircraft met British standards. Reluctantly, the British decided to buy some P-40 Tomahawks, but because Curtiss-Wright was using all of its production, they tried to source some license-built versions from North American Aviation. Instead, NAA promised a new fighter aircraft which could outperform the P-40, and after some back and forth on the design details, the P-51 was born.


One of the XP-51s (Mustang Mk.I) retained by the USAAC for evaluation. Original disinterest in the P-51 from the United States would give way to mass production once British cooperation bore fruit.


      The Mustang came into an element of its own once Rolls-Royce engineers installed Merlin 65 engines with two-stage supercharger to the five Mustang X prototypes, while NAA for their part installed Packard V-1650-3s (Merlin 61s) in two XP-51Bs. At altitude, the aircraft delivered speed improvements of around 50 miles per hour. Between the excellent high altitude performance and its very good fuel capacity, the USAAF became very interested in the Packard Merlin-powered Mustangs, producing the P-51B, then C, and eventually D variant which had a V-1650-7. However, the Mustang lineage underwent an interesting split even before the XP-51B had left the ground.

      The question that prompted the beginning of the “Lightweight Mustang” was simple: why is the Mustang so much heavier than the Spitfire? Despite occupying similar footprints in terms of size, the Mustang was 1,500 pounds heavier empty and the disparity was even larger loaded (due to the Mustang’s greater fuel capacity). When the Spitfire was already struggling to deal with the Focke-Wulf Fw 190, the heavier and less maneuverable Mustang would surely fare no better. Edgar Schmeud, the Mustang’s chief designer, got the idea to create a new Mustang that weighed less while also investigating new engines to produce more power. The combined effect of both of these ideas would be a significant improvement in performance. Upon putting forward a proposal for a new design, known by the company code NA-105, Schmeud secured a contract from the USAF for five prototypes.


This chart shows projected performance for the XP-51F based on P-51B flight data. The top speed improvements compared to the P-51B were already good, but the rate of climb and maneuverability enhancements were where the XP-51F would really shine.


      The NA-105 would be produced in three versions: the XP-51F, XP-51G, and XP-51J, the latter of which was added later on to test an Allison engine. In order to prepare for production, the NAA design team first had to figure out how to save weight in the first place. To this end, Schmeud visited Supermarine in Britain to examine the Spitfire for inspiration. After Supermarine had weighed the individual parts for the Spitfire, their findings were interesting - because British standards did not require the same structural rigidity as American aircraft, the components weighed less. Other weight savings were introduced by using new aluminum alloy for the plane’s skin, incorporating plastic components, using a thinner wing with redesigned shape, removing the fuselage fuel tank (though the wing fuel tanks were slightly increased in response) and lightening the ammo load to just 250 rounds per gun. In all, despite appearances, the NA-105 might as well have been a new aircraft. These changes resulted in a plane which, while still heavier than the Spitfire, was much closer to its weight than before, with an empty weight in the 5,700 pound range.


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The first XP-51F, s/n 43-43332, was unarmed. The aircraft’s new cradle made the engine bay look markedly different. While extremely difficult to distinguish, it would appear this aircraft used the V-1650-3 rather than the V-1650-7 as some would purport. To an extent, the aircraft was designed to British specifications, though in the end, Britain would not place a production order for any of the lightweight Mustang lineage.


      Like the Mustang itself, the XP-51F had a rather quick turnaround time. From the approval of the contract in mid-1943, it only took 7 months for the first XP-51F to get off the ground in February of 1944. Due to its significant weight reductions compared to the P-51D, the XP-51F handily outpaced it, achieving a maximum level speed of 466 mph (750 km/h) compared to the P-51D’s 440 mph (708 km/h) despite using a much weaker V-1650-3 compared to the D model’s V-1650-7. In addition, the rate of climb was superior, with a time to 20,000 feet (6,100 m) of 4.9 minutes compared to 7.3 minutes for the P-51D. Maneuverability was enhanced by the lower wing loading, making the XP-51F a clear improvement over the P-51D for short range operations at nearly any altitude. Provision for drop tanks was kept in the event that the plane would be used for escort missions, though the significantly reduced internal fuel capacity would hamper its effectiveness.


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XP-51F s/n 43-43334 is seen here at Boscombe Down in 1944 after being transferred to Britain. For some reason, the guns don’t seem to have made the journey over the Atlantic. The experimental type was given the RAF serial FR409. Some say that this Mustang was called “Mustang Mk.V” by the British, but this seems unofficial if not just made up.


      The third and final XP-51F was sent over to the RAF at the end of June 1944. However, for one reason or another, they didn’t seem particularly interested, as official testing at Boscombe down was very brief and no real performance data collected. Eventually, it found its way into the hands of Supermarine test pilots who took it for a spin and recorded their results. One glaring issue was that the XP-51F had pretty severe rudder stability problems. Aileron control was also bad at higher speeds, but at low speeds up until the point of stalling control was extremely good. The final major gripe was the inclusion of a seemingly pointless hydraulic seat raising system, along with the canopy being too oversized for its own good. However, there was plenty of praise to go around. The stall speed of 92 mph (148 km/h) indicated airspeed was exceptional, and it was a very pleasant plane to handle at low-medium speeds. In addition, the hydraulically powered sliding canopy would enable pilots to open it and jettison at higher speeds. However, the USAF had no need for a dogfighting Mustang when the P-51D competed well with enemy fighters at altitude and whose main service objective was bomber escort and ground attack. Meanwhile the RAF were pursuing not only high-speed developments and refinements of the Spitfire but jet powered aircraft in the form of the Meteor and Vampire, to which the XP-51F generally compared poorly. Had it been received and tested thoroughly earlier, the XP-51F may have found a British order. Unfortunately, this is another “what if” to add to a long list of aviation industry ventures.



Specifications

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North American Aviation XP-51F

Dimensions:

  • Length: 32 ft 3 in (9.82 m)
  • Span: 37 ft 0 in (11.29 m)
  • Height: 13 ft 8 in (4.17 m)

Weight:

  • Empty: 5,634 lb (2,556 kg)
  • Loaded: 8,500 lb (3,856 kg)

Propulsion: 1 x Packard V-1650-3 12-cylinder inline engine

  • Takeoff horsepower (S.L., 150 octane): 1,400 hp
  • Max combat power (150 octane):
    • 1,700 hp at 5,750 ft (1,753 m)
    • 1,550 hp at 17,750 ft (5,410 m)

Maximum speed: 466 mph (750 km/h) at 29,000 ft (8,839 m)

Ceiling (estimated): 45,000 ft (13,716 m)


Armament:

  • Guns:
    • 4 x .50 caliber (12.7 mm) AN/M2 Browning heavy machine gun (250 rounds per gun, 1,000 rounds total)
  • Drop tanks:
    • 2 x 75 gallon (284 liter) drop tanks

Crew: 1

Additional equipment: N/A




Why it should be in the game

      The XP-51F would provide an interesting lighter weight version of the Mustang to the British and/or American tech trees. As most of its deficiencies aren’t really an issue in War Thunder, it can be considered an upgrade in nearly every respect to the P-51C despite having a weaker engine. However, pilots would have to be conservative with their ammo as the provisions for 250 rounds/gun are not as ample as other Mustang variants or U.S. planes in general. As I said in the introduction, the Mustang is a story of Allied cooperation and I would personally be happy to see this plane and its cousin, the XP-51G, in both tech trees.


Sources

2 Likes

+1!

So it never had guns while in Britain and the only connection to them is that they tested it (maybe not even that)? This is even worse than the Swedish T-80U, Mi-28 and AH-64…hard pass gor Britain.

+1 for US

1 Like

Someone doesn’t like to read
They didn’t just trailed it but helped make it
You just see Mustang and go no Britain can’t have it when you don’t even know the History

You also didn’t read the part where it was rejected because Britain no longer had interest in it, and that the guns where removed when it was transferred to them. For all I care, it can go to Britain, but it should be the one without guns. Have fun with that.

Besides, Britain does not deserve to have a P-51 that is better than most US ones. They don’t need it, it doesn’t fit in their tech tree and they have far more of their own vehicles, especially prototypes, left to add. P-51s, especially variants similar to the high performance P-51H, should remain unique to the US tree.

One it had guns at some point which were 50cal that Britain already had
Two the USA also rejected
Three UK helped make it
Four Do you know who the intended client of the original P51 was BRITIAN

3 Likes

5 Likes

The point I’ve been making in this post (which seems to have flown over everyone’s heads) is that the Mustang is a story of cooperation between the U.S. and U.K. Whether you like it or not, the only reason the Mustang even exists is because Britain placed an order for it, and whether you like it or not the USAF didn’t give the Mustang a second glance until Rolls-Royce engineers installed a Merlin in the Mustang X. At the same time, the Mustang wouldn’t have been born without the genius of Ed Schmeud and his underlings at North American Aviation and the lightweight Mustang program was his brainchild. Throughout its development the story of cooperation continues. British and American engineers were closely involved with the XP-51F/G and the primary divergence only occurred when Packard’s engineers developed their own injection system for the Merlin to use in the P-51H.

Mainly, I fail to understand how

  • A plane that was born out of cooperation between the U.S. and U.K.
  • A plane made possible thanks to the great engineers of both nations
  • A plane evaluated and equally passed over by both nations

should be deserved by any one more than the other. In my opinion, the Mustang does fit the British tech tree and it’s rather ignorant to claim otherwise. And this “light fighter” Mustang is an interesting blend of British and American doctrine which would be at place in both tech trees. It would offer a superior dogfighter for the Americans while giving the British a plane with a little more potency in the energy fighting department.

I agree. Does that mean Britain shouldn’t also get vehicles that they had a large stake in?

The world doesn’t revolve exclusively around the American tech tree. You don’t see anyone saying America doesn’t deserve the Mustang because the British installing the Merlin made it so much better than anything Allison could do that they didn’t revisit the old engine until the XP-51J.

4 Likes

The point about Britain not needing it is that they would get a high performance P-51, while ALSO having Spitfires and other planes, reducing the uniqueness of the US tree. Why play US when you can get the same P-51 in another tree which also has some of the most meta prop planes in the entire game?

Gameplay should always come first in this game, and having multiple trees filled with the same content ruins this aspect, especially if there would be a guaranteed P-51 and Spitfire on the same team. With good players, it would lead to an unbeatable combination, which the US wouldn’t be able to utilise because they don’t have Spitfires (Corsairs and the like are much worse for gameplay purposes).

This wouldn’t effect gameplay its one plane that was meant and co developed by both countries

You point is just no UK can’t have any P51 as it would ruin uniqueness

my guy thats not how trees work

it be like me going no America shouldn’t have Harriers as it would ruin the uniqueness of the British tree

I’ve seen how you respond on other suggestion you just want nothing remotely American even if other nations are involved to go any where but America

2 Likes

Your argument about Harriers makes no sense as the US actually used them, specifically made their own modifications, and then also was the only reason the Harrier 2 exists for Britain at all.

While I do mostly comment on American equipment, my opinions are not limited to them - I don’t want to see similar situations such as the Hunter in the German tree or a T-90 in the British tree, which is why I heavily dislike these kinds of suggestions. Makes the game monotonous for every tree to have other countries equipment, even though they have more than enough of their own to be added.

Almost like this Prototype wouldn’t exist if it wasn’t for the British

Also i was mainly talking about the Harrier 1 s

But these situations are nowhere near alike, as the UK actually used the Mustangs and participated in their development, whereas the Hunter F.58 in Germany and T-90 in the UK have nothing to do with their respective TT, and I have commented against them in the past. But if a nation actually bought examples of it, there’s no reason they couldn’t be suggested.

And it’s not like the US has a shortage of unique aircraft that can be added into their TT either, let’s be honest.

3 Likes