Speed, climb & firepower are much more important. With these, you can dive on an opponent & destroy him in one sudden attack, or refuse the combat & flee if outnumbered.
That is more or less how the Flying Tigers dealt with the Zeros over China.
The excellent Rolls-Royce “Merlin” (built by Packard under licence) was use extensively by all US aircraft. It was a very powerful, smooth inline engine, with excellent characteristics. I recall reading that these engines would run fine, even after being hit by flak, bulets, etc.
The later-model P-51’s had Packard Merlins instead of Allison V-1710’s, yes, but what other US planes had them?
The Mustang used the Merlin. A few other types used:
[ul][li]P-38 Lightning: Allison V-1710 (V-12)[/li][li]P-39 Airacobra: Allison V-12[/li][li]P-40 Kittyhawk/Tomahawk/Warhawk: Allison V-1710[/li][li]F6F Hellcat: Prat & Whitney R-2800 (Radial)[/li][li]P-47 Thunderbolt: Pratt & Whitney R-2800[/li][li]SBD Dauntless: Wright R-1800[/li][li]F4U Corsair: Pratt & Whitney R-2800[/ul][/li]Now, I’ve just got out of bed and haven’t finished my first cuppa joe yet; but I think the USAAF used P-40s in North Africa, and P-51s, P-38s and P-47 in the ETO (plus some Spitfires – around Italy, I think). They used the P-39s in the Pacific early in the war, but it was obsolete by the time the war started. The Russians thought it made a swell tank buster though. I can’t think of any non-radial USN aircraft. Off the top of my head I can think of these carrier-based aircraft the Navy used: F4F Wildcat, F6F Hellcat, SBD Dauntless, TBD Devastator, TBM Avenger, and F4U Corsair.
So it seems that most U.S. aircraft used radials. Earlier designs such as the P-39 and P-40 used in-line, as did the P-51 (which started out with an Allison); but they also used the radial-engine P-47 (first deliveries in 1942).
Geezzzz, we won. Nuff said:::::
Which, why, when, … in the end, if anywhere near matched, it came down to the pilots abilities and the ‘war machine’ backing him up. Also to the side that took it’s experienced pilots out of the fight to train new pilots …
Best pilots, look to sailboat class racing to find a way to know. Best plane or engine, need to define the box and take the pilots out of the equation as best you can but you can’t totally because unlike ICBMs, the planes need pilots. So just stats does not tell the story…
As to why which engine, look to $$$ and politics, not just need or ability or stats… No simple answers…
You guys are asking for technical answers to a subjective question…
All former USN aircraft - and there’s not an inline engine anywhere to be seen.
The Royal Navy Fleet Air Arm had some, though, like the Seafire.
Johnny L.A.–the Merlin-equipped Corsair was post-WW2, a Korean-era aircraft.
I’d like to add that the damaged cylinders would be easy to replace as well.
Although wasn’t the Hellcat released well into the war. I was under the impression that by the time the hellcats were in widespread use the quality of japanese pilots was already falling like a stone from casualties/attrition.
Uh… The Corsair was at no point powered by a Merlin engine, and was very much a World War 2 aircraft, being designed in 1938 and flown in 1940.
While it was used quite a bit in Korea as a close-air-support aircraft, its heyday was the Pacific theatre in World War 2.
About halfway through. Fall of '43?
Another factor was that by the second year of the war the USN had developed tactics (such as the Thatch Weave) which reduced or nullified the strengths of the IJN’s aircraft. According to Wiki, pilots flying the F4F had an overall kill ratio of 6.9:1; and though it can’t hold a candle to the F6F’s 19:1, it was pretty respectable considering the opposition.
My guess, here, would be that you are drawing performance conclusions based on paper specifications that are not supported by the actual flight characteristics of the planes. I have never read anything from the European theatres that suggested that pilots of P-47s were told to not mix it up with Bf-109s in the way that pilots of P-40s, P-39s, (and, to a lesser extent, F4Fs) were explicitly told to avoid dogfighting A6Ms. Personal recollections by pilots such as Robert Johnson and Frances Gabreski speak repeatedly of engaging Bf-109s in one-on-one dogfights wiith their P-47s without conceding anything to the German fighters.
Power-to-weight (or even power-to-wingloading) comparisons provide a nice thumbnail sketch of how planes might compare in battle, but they do not provide an accurate way to evaluate actual performance. The F4F was much closer to the A6M in paper performance while the F6F was quite a bit heavier, but F6Fs did dogfight A6Ms and won consistently in those actions.
I’m not sure what apparent superiority the in-line was supposed to have had over the radials at altitude. The P-47 was the absolutely finest dogfighter in WWII above 35,000 feet and was actually designed with a “work” altitude above 40,000. Of course, since the bombers it was defending flew between 22,000 and 27,000 feet and the Germans and Japanese never produced a bomber that went any higher, the P-47 never got to flaunt its capabilities, there, and once the its rugged construction and two extra machine guns proved their worth in ground attack roles it found itself flying a lot of missions at the opposite end of the sky from its designed role, but it pretty well disproves any natural superiority of in-line over radial at altitude.
As to the USN fixation of radial engines, I had always read that it was a pretty straight concern for weight that shaped that decision.
Generally, higher power to weight ratio - a liquid-cooled engine operates within a narrower temperature range (both within any given cylinder and between cylinders), so clearances can be tighter, etc.
Its dogfighting ability was due mainly to its *diving * ability from the altitudes its turbocharger let it reach. It was not very maneuverable lower down, but it still had a good kill ratio due to its damage tolerance (largely due to its lack of a cooling system).
The same issue existed for land-based aircraft, always had. I’d vote for commonality.
The long nose of in-line liquid-cooled engines made for poor forward visibility in take-offs and landings. Carrier aircraft had to be robust (because of the high forces in the take-off and landing cycle) and often sacrificed some performance to get it.
You’re right.
I recall that one class of formerly air-cooled engine aircraft was retrofuitted, but mixed it up with Corsair.
Maybe you’re thinking of how the P-36 became the P-40?
I suppose that makes a good hypothetical reason. Beyond the theory, however, that does not appear to have been true in real life.
That is not dogfighting. Its weight probably did provide a measure of success, (as superior diving capabilities allowed P-40s to score against A6Ms), but P-47s actually held their own in dogfights at all altitudes, not simply through bounce and zoom tactics. Above 35,000 feet, no fighter was more maneuverable. Since the bombers it escorted flew between 22,000 and 29,000 feet and no Axis bomber ever flew much higher, it never got the reputation for its performance at high altitude (and with its two extra machine guns and rugged construction, it found itself in the role of ground attack), but it outperformed all possible competition–Axis or Allied–at the highest altitudes.
Don’t forget when comparing kill ratios between US planes and the A6M that the Zero did not have self sealing fuel tanks or armor for the pilot.
IOW, while highly maneuverable, were rather easy to shoot down.
I recall reading of a P-47 pilot over Europe who’d been badly shot up and was limping home. He couldn’t maneuver well and his guns were jammed so he was praying he didn’t get spotted, but of course, a Bf 109 found him. The enemy pilot pulled alongside and looked at him a long moment, then dropped behind. The Jug pilot scrunched behind his armor plated seat back and felt the plane shudder from a stream of hits – to no effect.* The Bf came along side again, then dropped back for a second burst – still no kill. A third lookover and Our Hero, rather cheekily, gave a little wave. After another, rather shorter try and he was still flying. Pulling alongside, the German pilot – presumably out of ammunition – popped a salute and peeled off. The Thunderbolt made it back to England without further adventures, but it never flew again.
Sometimes tough is better than agile.
*MGs only, I assume. If it was a Fw 190 he would have been toast.