Glider
Captain
Schweik - you marked this posting as disagree, I would love to know what you disagree about it as your comment in italics has little if anything to do with reality.
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Schweik - you marked this posting as disagree, I would love to know what you disagree about it as your comment in italics has little if anything to do with reality.The question is what has that got to do with the relationship between G forces and speed. By the way stalling speed also has nothing to do with it and I am confident that every fighter could pull over 4G. It's nothing special.
So just to repeat myself where did you get the idea that the following statement has anything to do with reality?
P-40s could sustain far more than 4Gs and the limit was basically what the pilot could endure. Of course any WW2 fighter will lose altitude in a turn though naturally. Usually you aren't pulling G's at all unless you are going pretty fast to begin with
Schweik - you marked this posting as disagree, I would love to know what you disagree about it as your comment in italics has little if anything to do with reality.
The main problem with both the P-40 and the Typhoon is that they had terrible performance at high altitude. All German Me-109 and Fw-190 marks easily outperformed them at altitude. Most combat in NW Europe took place at high altitude, because Allied heavy bombers flew at high altitude. Thus, as fighters, both planes are equal failures. In North Africa, where most (but not all) bombing missions were lower altitude ground support missions, the poor high altitude performance of the P-40 and Typhoon was not as relevant. The P-40 (Kittyhawk) gave a decent account of itself in North Africa. It could hold its own against 109's at low altitude.
With thousands of P-40's and Typhoons built, something had to be done with them other than high altitude combat, which they were really bad at. Thus, attempts were made to convert them to ground attack planes. The Typhoon, with its heavy wing construction, excelled at this. It could carry a bomb/rocket load that the P-40 couldn't match. It was also very fast at sea level. In fact, no Allied or German plane could catch it down low. It was the only plane that could intercept the German V-1 rockets.
Where the P-40 excelled was against Japan. Japanese planes, with with their Low Wing Loading, which gave unparalleled maneuverability at low to mid altitudes, also mitigated against it at higher altitudes. The P-40 (as well as every US Fighter), had a more powerful engine and a heavier, stronger air-frame. This gave them, respectively, a higher service ceiling and superior dive performance. This enable the "dive and swoop" tactics that the Japanese were never able to counter throughout the war. These tactics were developed by General Chenault and the Flying Tigers. Thus, their fantastic victory to loss rate. The P-40 would use its higher service ceiling to gain an altitude advantage. They would then swoop down on their opponent in a single firing pass, and then use the momentum of the dive to regain altitude. The Japanese couldn't out dive them, and because their Low Wing Loading gave them inferior high altitude maneuverability, they couldn't out turn the P-40 in its dive either. As long as the P-40 (and all US fighters) did not get caught at low altitude or in a turning dog-fight, they would usually win.
Remember, there are always engineering trade-offs when designing an airplane. The Laws of Physics tell us that the factors that make a plane maneuverable at low altitude will make it less maneuverable at high altitude. An engine optimized for low level performance will mitigate against it at higher altitudes. There are also speed vs maneuverability trade-offs as well as range vs weight trade-offs. An aircraft designer can either design an all-purpose plane that does many things average-ish, but does not excel at anything (P-51), or he can design a plane optimized for a specific role (F-6 Hellcat). It all depends on what the end-user tells the designer what it wants. The military try to envision future wars and a plane's role in that war. They will then give specifications to the designer as to what they want the plane to do, and the designer will make it. This is a long process, so if the military get their initial specifications wrong, it will take years to correct. The F-4 Phantom is an example of a plane that was used in a role that the military hadn't anticipated, dog-fighting with lighter, more maneuverable fighters, rather than being a stand-off, air-to-air missile platform. It took years to overcome this screw-up, and to develop the F-15 and F-16 to overcome it. An example of a purpose built plane done right is the Spitfire. The RAF envisioned a certain role for the plane and the designers build it exactly for this role. The RAF correctly foresaw the Battle of Britain and built a fighter to fit this exact scenario, a short-range, high-speed, high-altitude point defense fighter for use over Southern England. The Spitfire was designed and optimized for this specific role. Thus, it excelled. It was not as successful in other roles, such as bomber escort, where it was handicapped by its poor range.
So, the short answer to the question is: in NW Europe, both the P-40 and Typhoon were equally bad. However the Typhoon became an excellent ground support plane in ways that the P-40 could not match. In the Pacific, the P-40 was an effective fighter, so long as it used the right tactics. The Typhoons were never tested in the Pacific.
A sustained turn is, by definition, one that doesn't lose height, the plane can sustain a higher instantaneous turn but lose speed or height. The pilot can sustain a higher g in a instantaneous turn too. But a sustained turn doesn't lose height. I think I read here that most WW2 fighters could sustain a max of 4-5 G in turns.I thought you had noticed, G force and speed are in fact closely related, there were several good posts on this in the thread. Your contention that G force has nothing to do with speed is completely wrong. That is why I disagreed.
So, in summary, the Typhoon:
- was faster at all altitudes
- climbed better
- turned better
- dived better
- had far superior firepower (only a few Typhoon Is with 12 mgs were built)
while the P-40F could fly 90 miles further on internal fuel, had a better roll rate and a slightly higher ceiling.
Whilst, I agree with most of this, I think you'll find that it wasn't until the end of 1942 that the Typhoon had its tail strengthened so that it could pull out of a dive and the P-40 could be pushed over 500 mph although it wasn't recommended by the manufacturers, so for me the P-40 in 1942 is better as at least you come out of the dive even if there was some damage to the plane. As for top speed, 25 mph in top speed isn't going to lose you a dogfight. The top speed of the Typhoon is of course faster low down, but again by the end of 1942, there was increased boost available in the P-40F/L. In 1943 the Spitfire LIX/XII come along with adequate performance to intercept Fw 190A tip and run raids. The Typhoon in mid 1942 to mid 1943 is clearly the fastest low altitude fighter and best for intercepting Fw 190A's. In the East, the Soviets operating at very low levels coped with the P40E-1/K with over boost. I repeat, IMO, the P-40 was the better all round fighter and that the Typhoon is niche for the ETO.
Diving in a P-40 wasn't all beer and skittles. There were a lot of directional instability during dives, the reason for the lengthened fuselage on later models. A lot of trimming and rudder were required, and the stick forces for pull out were high.
But the better climb and acceleration in a dive or on the level would help win a fight.
That the Typhoon only served in one theatre does not make it a "niche" aircraft. Considering the theatre it operated in was probably the world's most defended airspace - certainly in terms of flak, and later with fighters.
There is nothing the P-40 could do in Africa, the Middle East, MTO, CBI or the PTO that the Typhoon I could not.
A lot of the P-40s superior diving ability is hype.
The Manual for the N (and others) says it was red lined at 480mph IAS, why should we say it is OK to push the P-40 passed this and not OK to push other aircraft past their red line?
In training the P-40 was not supposed to be dived faster than 350mph IAS (page 61) and the pilots were told to leave 5-8000 ft for pullout. The plane also wanted to roll to the right in a dive, the higher the speed, the greater the tendency to roll.
The P-40 was not immune to compressibility, it just didn't operate very often in the air space that compressibility was a problem.
Page 67 in the manual, "Vertical dives from 20,000ft are not recommended because of the danger of compressibility."
If you have a P-38 doing 400mph at 25,000ft and it goes into a dive it can hit it's compressibility limit pretty quick. A P-40 is starting 30-70mph (depending one engine, and exact altitude) slower to begin with, has to accelerate up to the compressibility speed limit in the dive and is getting into thicker air where compressibility is less of a problem.
It isn't just the straight line speed. The 25mph represents an amount of surplus power than can be used for climbing or turning a little harder without losing speed (or as much speed)
say you have a 375mph plane and a 350mph plane and they are both doing 300mph in a turn. The faster plane (enve if it is going the same speed) has more options, it can climb better while turning at 300mph, it can turn tighter (maybe not a lot) while still doing 300mph.
At which point the controls are solid and there is a significant danger of you digging a large expensive hole in the ground.
A couple of points
25mph is enough to lose a dogfight or evade being shot down unless the opponent is pointing directly at you at the start. The Typhoon would be out of gun range in about 20 seconds, however the true speed differential is a lot more than that.
The Spit LIX wasn't as fast as the Typhoon and wasn't as good when intercepting the FW190. Second point add as much extra boost as you like to the P40, it still wouldn't match the Typhoon at the equivalent time. This also had extra boost, better fuels and so on.
Russia isn't relevant for a number of reasons. One Russia as a nation was far more interested at getting more Spitfires and P39s rather than P40's and of course they didn't get any Typhoons.
Hello Kevin J,
The choice of comparison between Typhoon and P-40F was an interesting one.
Although the P-40F had the highest maximum speed AT ALTITUDE of anything before about the P-40N, it was also one of the heaviest of any of the P-40 variants. It didn't tolerate over boosting that the early Allisons did and as a result was one of the slowest at low altitude and didn't climb particularly well.
About the only things it really had going for it in a contest against a Typhoon were much superior roll rate and agility and of course reliability. There isn't a practical altitude at which the Merlin P-40 can control the fight unless the Typhoon pilot is incredibly stupid.
Remember that the Merlin P-40 with a single stage supercharger was only a medium altitude fighter at best and there is no altitude at which the Typhoon does not have a significant speed advantage.
The Typhoon does have a few disadvantages such as its initial lack of engine reliability, a vibration from the engine that fatigued its pilots and also carbon monoxide in the cockpit, but none of that really matters much once the fight has started.
- Ivan.
This is all speculation to suit a preconceived agenda.
You can also turn with the nose down, which was in fact a favored tactic in the P-40 (as Robert DeHaven described his method for shooting down Zeroes). Sustained turning also is affected by drag which the larger Typhoon with the much bigger and thicker wing would suffer from more.
We need to consider the condition/set up of the test plane and it's common usage.
The P-40F may have been a 370+mph plane with a clean belly but very few of them were flown that way in combat.
I don't know about later ones but the Spit MK I (at 6lbs boost) and the 109E couldn't sustain more than about 3Gs. Planes with more power but the same (or nearly the same) drag could sustain higher G turns. But 5 Gs seems a bit high? The Spit MK I having to dive at a 5-10 degree angle to maintain a 4 G turn depending on speed.A sustained turn is, by definition, one that doesn't lose height, the plane can sustain a higher instantaneous turn but lose speed or height. The pilot can sustain a higher g in a instantaneous turn too. But a sustained turn doesn't lose height. I think I read here that most WW2 fighters could sustain a max of 4-5 G in turns.
Once again, this is not valid comparison. There is no way of knowing whether P-40F/L would manage to achieve 260 victories in the ETO, deployed in the same numbers and flying the same missions as the Typhoon, and vice versa.
Not all sources agree that 592 is the number of victories scored by USAAF P-40's in the MTO; it is the highest number being bantied about. However, whatever number of victories they got, they were shared by 16 squadrons.
I don't know how many Typhoon squadrons shared the 260 victories?
All speculation?
The manuals were "speculating" about the dive speed limits? I gave you the page numbers, look it up.
as for the P-40 not operating very often where compressibility was a problem, well look that up too.
How many aircraft had compressibility problems under 15,000ft.
The faster airplane can also "turn with the nose down" which is called losing altitude or a diving spiral. If you are the pursued aircraft then a shallow dive while turning will keep the speed up but it may not keep the faster aircraft from following. "turning with the nose down" does not eliminate the power advantage the nominally faster plane has.
Typhoon also has a lot more power to counteract the drag. That is what the extra speed represents. Surplus power in a particular situation as I tried to show.
I think we know who has the preconceived agenda
Actually, that isn't enitrely true. Memoirs and squadron histories specifically mention removing things like bomb shackles when they were prepping for fighter opposition. Basically they had two configurations, dirty / heavy and light / clean. The former was for mostly FB missions, the latter was for mostly air superiority missions. They did of course however still keep the extra fuel tanks. 324th FG P-40s almost always flew with 6 guns and wing bomb shackles, 325th FG typically just had the fuel tank and four guns until most of the air-to-air fighting was over.
Also I didn't bother to correct this the last time you made the claim but they did actually manage to fit two or three large bombs (up to two x 1,000 lbs or 3 x 500 lbs) on P-40s, and they RAF and also the Russians) also did fit them with rockets. I think you know this because we have discussed it before.
The thing about the P-40 was that it was extremely versatile and kept exceeding expectations despite it's known limitations.
Schwiek,
Why did the factory pilot do 500 MPH dives on acceptance flights? And why didn't Curtiss just up the limits in the flight manual?
My guess is it's much more likely the factory pilot was "allowed " to exceed flight manual limits as they were new aircraft and such maneuvers were below structural limits. Not the same as a line pilot doing it on a war weary plane.
Cheers,
Biff
I cant remember where or who posted it, but was talking about the best of the WW2 era, mainly in respect of how much lower it was than what the plane and pilot could withstand in an instantaneous turn.I don't know about later ones but the Spit MK I (at 6lbs boost) and the 109E couldn't sustain more than about 3Gs. Planes with more power but the same (or nearly the same) drag could sustain higher G turns. But 5 Gs seems a bit high? The Spit MK I having to dive at a 5-10 degree angle to maintain a 4 G turn depending on speed.
And the speed tests say it was the under fuselage shackle and sway braces. No mention of underwing shackles.
This is pretty much a bit of misdirection in any case as most, if not all, of the heavy bomb loads were carried by Allison powered P-40s. Not the F or L.
The F was pretty much limited to the under fuselage bomb/drop tank position. Manual says that up to a 100lb bomb could be hung on each wing (it may have been possible to use 3-5 really small bombs under each wing totalling 100-150lbs)
It wasn't until well after the F that the P-40 was rated at 500lbs under the fuselage and 500lbs under each wing. The N (or at least some of them) was rated at 1000lbs under each wing and 500lb under the fuselage but this has little or no bearing on the question at hand, anymore than what the Typhoon could lug around in 1944 does.