A Radial Engined Fighter for the Australians to build (and maybe the Chinese and Indians)

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Assuming we are talking about the MTO, that's actually not really true, because Spitfires lacked the range and weren't available. There weren't any in Theater when the P-40D/E were introduced. By the time the K and M arrived, the (mostly US flown) F and then L were actually flying most of the escort missions for the older model Kittyhawks and the Hurricane dive bombers, as well as for the various light and medium bombers, because the Spit V lacked the range.

There is a thread on here where I read that during El Alemain, in Oct -Nov 42, the Spitfires only flew sorties about half the days (I think it was 17 days), whereas the P-40s flew almost every day.

But I take your larger point and don't disagree - the Allison P-40s were best below 12,000 ft (E and K) or about 16,000 ft (M and N). The F and L were good for about 22,000 and weren't hopeless at 25,000. The point was that all of them could hold their own quite well down low.

Being fast below 10,000 feet is handy, but that means they are still conceding the initial attack to the Germans or Italians, unless they did sneaky things like attack the German airbases. But apparently this was also a problem for Spit Vs, as they too adopted the 'big wing' tactic and learned to turn into attacks from above. Maybe due to the Vokes filter.


Yes I didn't say you didn't, but some other people have. Originally the P-40 was just dismissed as a "slow and unmanuverable" aircraft for decades, and in hundreds of books and online publications. Many books still report performance as if 42" Hg was the best they ever reached. Then it emerged maybe 20 - 30 years ago that lo and behold, they were actually quite agile, and could out-turn most of the European Axis aircraft. Then when that famous Allison memo came out, we also learn that they were quite fast down low. The new theory I often see repeated today is that while yes they could go fast very low by overboosting, they could only basically do that at sea level or 2,000 feet. I'm just pointing out that this ability apparently extended up to about 10,000 feet, or higher depending on the type.

I'd distinguish between 'overboosting' and WEP / WER in the sense that 'overboosting' is usually a fairly reckless and / or unsanctioned panic move by the pilot, often at very high boost level (pilots sometimes described the MAP going all the way around the dial since it only went up to 45" Hg in early models, and they didn't really know how far they had pushed it). This probably means a high chance of blowing the engine, or as Shortround6 noted, damaging it so that it will fail in a subsequent flight.

WEP / WER by contrast is like when the RAF or FAA increases boost settings for an engine, it implies that the new setting has been tested or 'vetted' and it is far less likely to cause problems with the aircraft, especially once they had strengthened the engines a bit.
 

point is that many P-40 and P-GH fans rave about the high WEP or overboost or whatever you want to call it.
A P-40E can make a lot of power at sea level, there are even video's about 1710hp or something. But that 1710hp (in the Mustangs) drops down to 1150hp at around 12,000ft and even less if you are not flying at max speed.
If you are "bounced" at 7-9,000ft and you flying at 2600rpm and 38in you will not have full WEP just by opening the throttle. You may only be 15mph or so slower than Mil power but even Mil power is slower than running straight and level and accelerating up to the speed that gives you the "full" boost you need to reach the full WER rating.
The closer you are to sea level the easier you can get a very large increase in power. However just like the WER rating when climbing it gets get very variable when you are at less than full speed.
some times you can dive away using your speed and sometimes you can't.

The Problem I have is the
"10,000 feet, or considerably higher depending on the type."
Considerably higher is about 13,000ft if the plane has 9.60 gears like the P-40M or N.
If you have 8.80 gears the considerably higher is actual barely higher at 10,000ft and not at all higher at 12,000ft.

That is what Critical Height or FTH mean. Those are the Altitudes at which the throttle is wide open and the engine/supercharger is maxed out and won't give you anymore power.
It also doesn't matter what the temperature is (unless you are in Russia) or the humidity or what you have for fuel or anything else.
doesn't matter if you pour 150 octane into the tank, the fuel has the same number of BTUs per gallon and you have to mix the fuel with the right amount of air to get more power and at FTH and above you don't have anymore air.
At lower altitudes you can feed more air into the engine and the result of more air and fuel that will resist detonation better can give more power but it won't do it above the FTH.

at below those altitudes that is where WEP or over boosting or emergence use comes into play. At less than critical height or FTH the throttle is not fully opened (even if the throttle ever is against the stop) and you can use this "surplus supercharger capacity" to make more power. Assuming that the extra power won't wreck the engine. Even before WW II RR has figured that the Merlin, assuming you could could find fuel that wouldn't detonate while running, was good for at least 1500hp at sea level (for either the Merlin II or Merlin X engines). That was the amount of extra airflow that was built into the engine that allowed to make 1030hp at 16,000 ft in the thinner air. Some engines were not strong enough to take the higher boost or extra airflow without breaking parts, Others had a strong enough engine but the fuel wouldn't allow it because at higher pressures/temperatures it would detonate. This is what made the Merlin so easy to upgrade just by putting different fuel in them.
 
While the change from the 8.80 gears to the 9.60 gears may not sound like much the airflow through a supercharger is proportional square of the tip speed of the impeller.

There are a few things that complicated it but the supercharger with the 9.6 gears has an airflow about 19% higher than the airflow using the 8.80 gears. It also take about 19% more power to drive the supercharger and it will give more than an 19% rise in temperature.
 
Shortround6 said:
point is that many P-40 and P-GH fans rave about the high WEP or overboost or whatever you want to call it.
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P-GH?
Shortround6 said:
A P-40E can make a lot of power at sea level, there are even video's about 1710hp or something. But that 1710hp (in the Mustangs) drops down to 1150hp at around 12,000ft and even less if you are not flying at max speed.
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I tend not to focus on the more extreme 66" or 71" Hg settings, for various reasons, but generally try to make the point about the authorized settings i.e. 60" or 57" or 56"


If you are bounced at cruise speed you are likely to be in trouble in any aircraft. The most important skill of the fighter pilot was situational awareness.


You are forgetting the merlin powered F and L, which were very important in the war though their history seems to have been largely forgotten.

Yes I understand all that, my point in this case is just that it was not limited to sea level or 2,000 ft.
 

I'd say that on this forum the P-40 gets a fair shake.
As a 'cure' against a theory that smells fishy, there is a number of original documents that can be obtained, either online or in print. Care needs to be used, as we've seen not all the original docs are void of mistakes.
 

I'd agree from what I've seen, overall, though there are still persistent myths. I'd say there seem to be a few people who are cognizant of the data and some still arguing for the old myths. I'm interested in clearing as many of the myths away as possible. For example, i don't think it's true that the relative success of P-40 units in North Africa from mid-1942 onward was due to top cover by Spitfires and P-38s. I bought Shores MAW series and it does not seem to be the case, to the contrary the US P-40 fighter groups in particular flew a lot of the escort missions for other types, and routinely faced Luftwaffe and Regia Aeronautica fighters on their own. The P-38s were mostly flying their own long range missions or escort for heavy bombers (B-24s or some B-17s) and the Spitfires were largely being used to defend the Allied airfields or in short range missions over the front (when their airfields were close enough).

There are a lot of myths about all kinds of aircraft and I've been thinking a bit how to reform some of the standard stat blocks that are usually reproduced in books and online. For example, top speed is often misleading if you don't know at what altitude, power, or weight, or even what variant is indicated. Power and speed is sometimes listed based on WEP and sometimes based on military power or lower, sometimes based on 'gross weight' with all kinds of extras and sometimes stripped down. Stats in general are often repeated for one particular variant even if it wasn't the main type in use, and / or even if there were many variants with widely different performance. Spitfire and 109 are good examples of this.
 
Wild_Bill_Kelso said:
P-GH?
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The P- "that must not be named" that had the engine behind the pilot. Several very ,very long threads mostly based off of one test report that one forum member turned into a conspiracy about How Bell aircraft was wrongfully denied it's rightful place as Americas best long range escort fighter and that the P-GH (ground Hog) could have escorted B-17s using basically the same engine as the P-40N.
Wild_Bill_Kelso said:
If you are bounced at cruise speed you are likely to be in trouble in any aircraft. The most important skill of the fighter pilot was situational awareness.
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Define cruise speed.
2600rpm and around 37-38in was supposed to max continuous and the highest the pilots were supposed to fly at unless in actual combat. depending on altitude a P-40E was using around 105-116gallons an hour. Nobody (except maybe in Russia ) was blasting around the country at military rating (5 to 15 minute rating) unless the enemy was in sight.
The 2600rp, 38in setting was a nominal 1000hp depending on altitude. a few hundred rpm less and a few inches less pressure and the engine made around 750hp and used about 65 gallons an hour. You could keep the plane in the air at around 180-200mph for a little over 30 gallons an hour using around 400hp but that was asking to be added to an Axis pilots score. The 1150hp rating could suck down about 130 gallons an hour which is another reason it wasn't used unless they needed to. WER could use up over 160 gallons an hour.
The 2600 rpm and 38in was sort of like the British max rich cruise setting.
Running out of fuel before you reached home base was a major fail in situation awareness.
Wild_Bill_Kelso said:
You are forgetting the merlin powered F and L, which were very important in the war though their history seems to have been largely forgotten.
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didn't forget them at all. They usually just confuse things when it comes to P-40/Allison discussions.
with about 2900 P-40D & Es and 1300 P-40Ks, 600 P-40Ms and about 3500 P-40Ns ordered before the end of 1943 the 2280 or so P-40F and Ls are interesting but don't really keep the issue on track. The P-40F & L seems to have been a North Africa/Italy operation with just enough scattered to the Pacific to make things interesting for modelers.
 

Ah ok gotcha, yeah I saw some of that


Never suggested they did, I don't even think the Russians did that. I know that in the Med, there was a pretty well defined SOP, when they saw enemy fighters (hopefully while they were still pretty far away) they increased throttle settings to military power, and if the enemy was above them as they often were, they would wait for the signal of the squadron leader, and then when he called "break left" or 'break right" the entire formation would firewall throttle, wheel into a tight turn and face into the attack, guns blazing. They would continue this process until the enemy a/c broke off the attack and left, or lost enough E that they were in range to be attacked. If they didn't, and the enemy a/c remained above them, they would just continue flying along.

In this interview, Bobby Gibbes described an incident where he had a Kittyhawk III which had a little more power available than some Kittyhawk II's he was leading. Presumably below 10,000 ft. He was able to pour on the coal and shoot down a bf 109 out of a flight of three, though he says he hit a different one than he was actually aiming at:

"Well I was a poor shot. Air to ground I think I was a very good shot. I could group my bullets and make sure they didn't run through. I could hold them on target while I went in and strafed. But air to air I certainly missed an awful lot of aeroplanes I fired at. I think the classic example was one day when I had a Kitty Mark III - I had acquired it illegally, I might say - and I had to give it back to the RAF later - but I had a little bit more horsepower than the rest of the squadron and when three 109s passed overhead or ahead of us, if I had waited to take the squadron with me, which normally I would have done, they would have got away.

But seeing them and knowing I had that bit more power I opened the taps and went after them.

I had a look at the three of them and I thought, if I pull a lead on the number one, number three could probably get a deflection shot at me, so I thought, well, I'll get number two first.

So I fired at number two. I must have misjudged their speed completely because the one behind, probably fifty yards behind, flicked over and went down smoking like hell. I looked round to see who else had shot at it but I was the only one in the sky. I then decided, well, I'll go after the number one and number two but, of course, they didn't wait for me. The one, incidentally, number three, did go in.

Yes, it was a successful mission. We had a big celebration that night in the squadron and a few of the 'Yanks' came over and they thought the shooting was quite brilliant and I had only fired very few rounds. However, during the night I managed to get quite a few grogs on board and I decided that I'd confess that I hadn't even aimed at that one, I'd aimed at the one ahead of it. And, of course, when I did tell them of course no one believed me, but it was true."

The British intentionally flew at low enough altitude in the Med that they still had enough power available to do all this.

In the Pacific and China it was a lot less strict, they would fly in flights of four typically and when they saw enemy aircraft, either pour on the coal and get up to speed, or if they were too high to have enough power, they would dive to pick up speed, if necessary extend away from the enemy aircraft, zoom back up and go back into the fight. By then obviously at whatever they considered ideal combat power.


I think the SOP was that the cruise speed increased gradually as they came nearer to the zone where they were likely to run into enemy aircraft (In the MTO this was a bit safer because the 109s and MC 202s had shorter range, so didn't typically venture very far over Allied lines), so slow cruise initially, a bit faster as they got closer to the line. Probably still at max continuous until they spotted enemy a/c.


Well the production numbers don't really tell the whole story do they? They produced far fewer Spitfire Mk I than Mk V, but which one mattered more for the war?

Of the P-40 production, the ~2000 P-40F/L mattered a lot more than the P-40Ns, at least half of which ended up remaining in the US in training units and homeland defense, and many of the rest (basically of the ones sent to the British) were used just as fighter bombers. The other half were active in the Pacific and some in the CBI, but by the time they arrived the fighting was tapering off and they no longer had sufficient range to engage with enemy aircraft most of the time.

Almost the entire production run of the F and L played a substantial role in the destruction of the Luftwaffe in Tunisia, and with the overall victory there and in Sicily and Southern Italy.

The small number which made it to the Pacific were also rather significant as they equipped at least one squadron in the 49th FG during a key moment in the fighting around New Guinea.

The relatively small number of P-40K were also quite important in China / Burma, in the Pacific (in both US and Australian use) and in Russia. They provided substantially improved performance at what was still a very fraught period in the war (late 1942-early 1943). Quite a few of the P-40 aces flew the K.
 
MiTasol said:
Gibbes later formed Gibbes Sepik Airways operating, among other things, Junkers 52s and last I saw him was in the late 80s when he was flying a twin engine microlight powered by two lawnmower engines.
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That's so cool! Just from reading his interviews, I really love that guy.
 
I am guessing that he he referring to the Kittyhawk III which is a P-40M with the 9.60 gears.
In 1941 When the British were doing that whole "Lean into France" thing that cost so many pilots the RAF did actual learn some stuff. One is that it took a Spitfire about 2 minutes to accelerate from a cruise speed in the low 200mph range up to full speed. Which was pretty much the end of low and slow cruise technique. Slow cruise over the channel but as fast as fuel consumption would allow for the mission. This is also where the RAF worked on the low rev but high boost cruise regime.
Now some planes would accelerate quicker than others but if you were going slow (low 200 mph area) the whole fight would be over before you got up to speed or altitude. Unless you were the target
well, even if you were going faster than the First RAF pilots over France it could take a long time in combat to "pour on the coal" The faster planes that were initiating combat (or trying to Breakaway) could be doing 300-360mph or 5-6 miles a minute. The slower planes are moving also but the dive away, extend, zoom back up and get back into the fight could actually take a while.
Some stories should be take with a grain of salt (in some cases the whole salt lick) Like the one about Russian I-153 fighters (biplanes with retractable landing gear) cruising with the landing gear down and waiting until the Germans in 109s had committed to their attack run whereupon the brave and skillful Russian pilots would do a fast 180 degree turn to engage their attackers while simultaneously cranking on a hand wheel to retract the landing gear. All before the Germans finished their attack run or broke off the attack.

There is a lot of room in breaking off attacks and trying to change altitude and or speed and "get back in the fight" Many pilots did get back in the fight, it just may not have been the one they left
Wild_Bill_Kelso said:
Well the production numbers don't really tell the whole story do they? They produced far fewer Spitfire Mk I than Mk V, but which one mattered more for the war?
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That could be loaded question
It depends if you are in the "Spitfire saved England in the BOB" camp or if you are in the the Spitfire was nice to have and saved a number of British pilots but the British might have been able to win using the Hurricane although it would have been a lot bloodier camp.
 

Isn't this how the groundhoggery began? With "new" information, that comes to light after the aircraft's reputation has been set?
 
Shortround6 said:
I am guessing that he he referring to the Kittyhawk III which is a P-40M with the 9.60 gears.
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Probably, though it depends on the altitude, he could be talking about the P-40K, the RAF referred to both aircraft as 'Kittyhawk III'. I'm not sure if a P-40M has more power than a Kittyhawk II at any particular altitude..?

Like I said already, they may have started out slow over their home base (if they knew they were out of range of 109s) but in the combat zone they stuck to a higher cruise speed. One good thing about the Boscombe Down tests on the Kittyhawk is that it tells us that the P-40D could make 322 mph at military power (42") with an external tank (at 8840 lbs), and 332 without (at 8485 lbs). So assuming they go to military power in the danger zone, they don't have too far to go to reach combat speed (and will already be getting some Ram, depending on the exact altitude) once they actually spot hostile aircraft. It won't take two minutes that's for sure.

Well I'm not talking about some vodka soaked yarn. The fighter strategy I described (turning into the attack etc.) was official British policy and is described the same way in multiple RAF pilot interviews. Similarly...

Shortround6 said:
There is a lot of room in breaking off attacks and trying to change altitude and or speed and "get back in the fight" Many pilots did get back in the fight, it just may not have been the one they left
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The whole 'hit and run' policy used in the Pacific and China is also quite well documented an attested to by dozens of individual pilots.


You don't have to go that far, I wasn't making any claim that Spitfire saved the world all by itself, I'm pointing out what I thought was obvious - most of the Spitfire Mk Is were heavily engaged in combat in a crucial battle for the survival of England, whereas thousands of Mk Vs were either more or less twiddling their thumbs in England, wasting time (and lives) "leaning in" over the Channel, or were engaged in secondary Theaters like North Africa. The difference is obvious and the analogy is clear unless you try really hard to ignore it
 
wuzak said:
Isn't this how the groundhoggery began? With "new" information, that comes to light after the aircraft's reputation has been set?
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I see where you are going there, but most of what I referred to has been known at least a decade or two and I think has already been discussed in multiple threads in this forum, and not necessarily especially contentious ones (or at least, not more than usual).
 
Wild_Bill_Kelso said:
Probably, though it depends on the altitude, he could be talking about the P-40K, the RAF referred to both aircraft as 'Kittyhawk III'. I'm not sure if a P-40M has more power than a Kittyhawk II at any particular altitude..?
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P-40K has the 8.80 gears, The P-40M has the 9.60 gears, anywhere above 7-8,000ft the P-40M is going to have more power in you are using WER.
Military power was, by the book, only supposed to be used for 15 minutes. What they did in combat is different. BUT Mil power could use almost a 1/2 gallon more per minute.
Another chart from the same test (same aircraft)
Dropping back to 2600rpm was worth about 20mph without the belly tank.
Military power was supposed to be the maximum power that a pilot was supposed to use during a flight without having to report it to the crew chief and the engineering officer in charge of squadron maintenance. Use of WER was to be noted in aircraft log books or maintenance records. It may call for more frequent oil checks (looking for metal particles), it may call for more frequent spark plug changes, it may call for the engines to be pulled out and replaced at shorter intervals for overhaul. It depended on how many hours were spent at WER after a number of flights.
If the pilot reported that he had been shot at or even pursued, or if he was even trying to get into firing position (even to strafe) all was OK. It was combat. Routinely "breaking the wire" because they were flying through enemy airspace was going to result in most pilots getting some sort of disciplinary action.

300mph at 2600rpm (anywhere from about 4,000ft to 25,000ft, faster in the middle) is going to be a lot safer and faster to respond than flying at 200-220mph. but running at mil power even if the gauges stay in the green is not really a good idea for the long haul.
Cruise chart for the P-40D & E
Wild_Bill_Kelso said:
The fighter strategy I described (turning into the attack etc.) was official British policy and is described the same way in multiple RAF pilot interviews. Similarly...
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Well the key point of the Russian story was the part of waiting for the Germans to commit to the "firing" attack before changing course.
A number of slow aircraft did wait for enemy fighters to almost within firing range and then jink to throw of the enemy fighters aim as the enemy fighter/s were going too fast to get the guns back on target before they went by the slow flyers and the fighters would have to do a 360 turn and come back, often repeatedly. But there was huge different between jinking and pulling a 180 degree turn in a small enough space to put your guns on target.

Turning into an "attack" to not quite the same thing. When you turn into the attack you are trying to disrupt the enemies attack before the enemy actually gets into firing position.
The enemy may decide to break off their attack and look for an advantage, they may decide to modify their attack or try to continue their attack with the firing angles changed.
If the enemy is going to start firing at 400-600yds waiting to turn till 700 yds isn't going to work. Do your turn when you can still complete your maneuver to face them head on or at least give them a very brief (almost head on) high angle deflection shot. If you turn away you are giving up the initiative to the attacker. They will decide wither to follow you into a turn or dive or climb or not.
Wild_Bill_Kelso said:
thousands of Mk Vs were either more or less twiddling their thumbs in England, wasting time (and lives) "leaning in", or were engaged in secondary Theaters like North Africa.
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They were still using MK Vs (one squadron) at Arnhem. Quite a few MK Vs were used in attacks/operations at the time of Normandy. Granted they had top cover from MK IX and the like but the MK Vs were not hanging around idle.
 
Shortround6 said:
P-40K has the 8.80 gears, The P-40M has the 9.60 gears, anywhere above 7-8,000ft the P-40M is going to have more power in you are using WER.
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Right but he doesn't say what altitude they were at. The K was apparently the popular one everybody was stealing etc.
Right but military power <> WER / WEP, you don't get disciplinary action for going to military power, and they apparently did increase power when they crossed into Axis territory (depending on who or what they were escorting) and these flights were not necessarily all that long once they got near the target area. I don't know precisely what boost setting or RPM they were at, as they rarely mention that much detail, but I know that increased power was used prior to contact because this is frequently attested. So I really don't think your original point was valid, you seem to be arguing for the sake of arguing.

Like I said, turning into the attack was SOP for the British fighter units in North Africa from about mid 1942, for all of them including the Spitfires. I could transcribe dozens of accounts of this, there are at least a couple of dozen in Mediterranean Air War alone plus numerous pilot interviews and historical accounts. Of course the timing is tricky, which is why the Squadron Leader had to make the call. Neville Duke recalled one incident where the SL ordered the 'break' in the wrong direction and three pilots lost their lives in rapid succession. But this was the tactic they used, and it apparently usually worked once established, particularly with the Kittyhawk II / P-40F/L, which is what Gibbes unit was flying at the time of his anecdote (they were one of only two British / Commonwealth units who got them)

Shortround6 said:
They were still using MK Vs (one squadron) at Arnhem. Quite a few MK Vs were used in attacks/operations at the time of Normandy. Granted they had top cover from MK IX and the like but the MK Vs were not hanging around idle.
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I think you are well aware that I never said Mk Vs weren't engaged in combat, but quite a few of those based in Britain were clearly under-utilized. Again you seem to be arguing for the sake of arguing. I think my original point is pretty obvious - the Spitfire Mk I had a far greater impact on the war. Just as the Kittyhawk II had a far greater impact than the Kittyhawk IV, or the Wildcat had a lot more impact than the Bearcat.
 
The following is probably self-evident to most of you:

The speeds the escort fighter and non-escort fighter groups flew at depended mostly on how far they were going, and what they intended to do when they arrived.

As a general rule the escorts flew at the speed of the formations they were escorting, or a bit faster as they moved around over/under the formations, at least until they reached the expected engagement areas.

Pretty much any(all?) non-biplane Allied fighters could keep up with the heavy bomber formations with engine settings still in the economical (ie weak mixture) range, even slower airframes like the Hurricane Mk II. If my information is correct, the Hurricane Mk II max weak mixture cruise (2650 rpm at +4 lb) was around 270 mph TAS at 20,000 ft, with a max rich mixture cruise (2650 rpm at +7 lb) of over 300 mph TAS at 20,000 ft. When the escorts entered airspace that they figured might be contested they would usually increase to max rich mixture cruise, or whatever sustainable rating they figured appropriate for the range they had to cover.

For non-escort operations, where max endurance times and range were not the primary problem, the fighters generally flew at higher speeds than when they were escorting heavy bomber formations. BUT, not always, as they still had to conform to speeds that would allow them to reach the engagement areas . . . which pretty much meant that they were limited to max rich cruise settings if flying more than across the channel.

Using climb (if different than max rich mixture cruise) or military power for anything other than climb or combat would severely limit engine life, and possibly make its use problematic during combat. This is the reason most engines were rated at what we (today, with hindsight, from our armchairs) might view as overly conservative.
 
Wild_Bill_Kelso said:
Right but he doesn't say what altitude they were at. The K was apparently the popular one everybody was stealing etc.
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That doesn't make a whole lot of sense.
A P-40K used 8.80 gears. It had the -73 engine. Yes it will give you 1325 hp for take off instead of 1150hp of the -39 in the P-40E.
The difference in the two engines was the -39 gave you 1150hp at 11,700ft while the -73 gave you 1150hp at 12,000ft (how good are your spark plugs or how clean are your backfire screens).
The -73 engine could NOT MAKE any more power at any altitude than the -39 engine could. Due to it's stronger construction they allowed the -73 to make more power down low, like for take-off or when the plane was low enough that the supercharger could make more than the 56in of boost the -39 was limited to to. Now to get to that power at 60in of pressure you have to be flying several thousand feet lower than the the plane with the -39 engine is flying making 56in of pressure.
We can argue about exactly which altitude that is according to how much you have Ram but that is basically it. The -73 engine will not give you any more power more than around 6000ft or so (No RAM Is 4300ft) than the -39 engine. Now in the story Officer Gibbes uses his superior power to leave the other Allied pilots behind and overtake the German planes that were flying above them and does so in such a way that his squadron mates are no longer in range or able to engage the enemy so how long did this take or what distance was involved?
Now if he was flying a P-40M (Kittyhawk III) with a -81 engine he would have several hundred more hp at around 9,000ft to 11,000 than his squadron mates and the story would make very good sense. Closer to 6-7,000ft his advantage over his squadron mates would get smaller and finally disappear. Over 11,000ft hew would still have an advantage although also getting smaller but not disappearing.

The story doesn't say he dove on the enemy planes and used superior power at low attitude to overtake the German planes.
Wild_Bill_Kelso said:
I don't know precisely what boost setting or RPM they were at, as they rarely mention that much detail, but I know that increased power was used prior to contact because this is frequently attested.
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So we are both guessing.
I have shown you that running at 2600rpm is only worth about 20mph over running at 3000rpm. You have seen that the manuals only want to you use the 3000rpm limit for 15 minutes (at best, some manuals say 5 minutes on the early engines)

Now increasing power to 2600rpm from an unknow setting was certainly easy enough to do. A P-40 could cruise at from 1800rpm or under up to 2600rpm. Speed could go from 183 IAS (216mph true) at 9000ft at 1800rpm to 261 IAS at 2600rpm (308mph true) so there was certainly more than enough ability to increase power prior to contact without going to military power.
Now if you are going down to bomb/strafe you do want the engine to operating at 3000rpm before contact. It you have a number of minutes to go at altitude before you are in the target area or you are flying cover for other aircraft (A-20 or Baltimore strike?) perhaps you don't want to be at Military power before you see enemy aircraft.



Wild_Bill_Kelso said:
the Spitfire Mk I had a far greater impact on the war. Just as the Kittyhawk II had a far greater impact than the Kittyhawk IV, or the Wildcat had a lot more impact than the Bearcat.
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Some strange accounting going on there, except that the Bearcat had zero impact on the war, never got into combat.
 

This was actually a really big issue in the Med. The reason they started fitting bombs to Kittyhawks and Hurricanes is in fact largely because of complaints by pilots like Clive Caldwell about escorting such aircraft as Blenheim bombers, which (purportedly) had a cruise speed of about 95 knots. Flying along above a flight of Blenheims at this speed was basically a death sentence for the escort. However fighter bombers couldn't fly super fast with a bomb either and a lot of them got jumped down low especially if the high cover missed the enemy fighters.

Later they were escorting aircraft like Martin Baltimores and Douglas Bostons which had a quite high cruise speed and could accelerate to much higher speeds when danger threatened. After they dropped their ordinance they would go into a shallow dive at full throttle to exit the area.
 
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