Best dive-bomber of the pacific

[FLYBOYJ]

Give the P-51 an annular radiator plus machinegun resistant armor around the pilot and you would have a much tougher aircraft. Those same changes would lower aircraft combat radius.

Raise the gross weight, affect maneuverability, raise the stall speed, etc., etc., etc....

[renrich]

The IJN CAP did engage the SBDs at Midway but their ability to interfere was lessened somewhat by the fact that they were at low altitude dealing with the VTs and had to climb to try to reach the VBs before they went into their dives. They could not disrupt the attack until the VBs were already in it but did try to defend while the VBs were diving, a difficult propositon and of course they attacked while the VBs were egressing.

One only needs a little common sense and a cutaway drawing of a radial engined fighter and a liquid cooled engined fighter to determine that there are many more areas on the liquid cooled fighter which are vulnerable to even rifle caliber hits. It is foolish to argue otherwise. An engine seizing up because it overheats is a serious problem anytime but especially over water. Aside from battle damage, coolant leaks were a constant problem and a cause for Spitfires and Hurricanes to become U/S as was pointed out by Shores in "Bloody Shambles.
The USN was correct in only being interested in air cooled engines for it's airplanes.

[RCAFson]

The IJN CAP did engage the SBDs at Midway but their ability to interfere was lessened somewhat by the fact that they were at low altitude dealing with the VTs and had to climb to try to reach the VBs before they went into their dives. They could not disrupt the attack until the VBs were already in it but did try to defend while the VBs were diving, a difficult propositon and of course they attacked while the VBs were egressing.

One only needs a little common sense and a cutaway drawing of a radial engined fighter and a liquid cooled engined fighter to determine that there are many more areas on the liquid cooled fighter which are vulnerable to even rifle caliber hits. It is foolish to argue otherwise. An engine seizing up because it overheats is a serious problem anytime but especially over water. Aside from battle damage, coolant leaks were a constant problem and a cause for Spitfires and Hurricanes to become U/S as was pointed out by Shores in "Bloody Shambles.
The USN was correct in only being interested in air cooled engines for it's airplanes.

Antiaircraft fire was light and there was no fighter opposition until after bombs had been dropped because of the preceding torpedo attack, which had drawn down the enemy fighters...
The Battle of Midway

I can only point to the sortie loss rate stats that I posted earlier.


One must also remember that combat losses occur from a variety of causes, and engine coolant loss is only one possible cause. If the design team can take advantage of the smaller frontal area, better power to weight ratio and lower specific fuel consumption of an in-line liquid cooled engine, they should be able to create a higher performing and more survivable aircraft. However, it is also the kill/loss ratio that becomes paramount since a higher performing aircraft with longer range will be engaging the enemy more often, potentially leading to a higher sortie loss rate, but with more kills overall and a better kill/loss ratio.

[FLYBOYJ]

If the design team can take advantage of the smaller frontal area, better power to weight ratio and lower specific fuel consumption of an in-line liquid cooled engine, they should be able to create a higher performing and more survivable aircraft. However, it is also the kill/loss ratio that becomes paramount since a higher performing aircraft with longer range will be engaging the enemy more often, potentially leading to a higher sortie loss rate, but with more kills overall and a better kill/loss ratio.

Would have, should have could have, a lot of loose speculation there... Amazing how in line engines despite some of their advantages, disappeared after the war with some rare exceptions (Shackleton).

I have worked on radials and have limited experience with liquid cooled inlines and I can say first hand the radial, if properly maintained and operated is twice as reliable as the inline, speculate and theorize all you want, I'd bet dollars to donuts that 9 out of 10 mechanics would agree with me in a heartbeat.

[renrich]

The source quoted, The Battle of Midway, to begin with is outdated. "The Shattered Sword" debunks a lot of myths about Midway. One of those myths is that the IJN carrier decks were packed with AC ready to take off. That is not true. Page 362 of "The First Team" by John Lundstrom states that "it appears that only about one third of the Enterprise SBDs were intercepted by the Japanese CAP." The battle records on both sides of this stage of the Battle of Midway are somewhat sketchy but regardless of whether the Zekes hit the VBs before or after they went into their dives the pilots of the SBDs were aware that they were in great danger from the CAP, unlike the bombing of the Tirpitz.

As far as playing the statistics game, P47s flew 423435 sorties in the ETO and had 3077 losses which comes out to be a loss every 138 sorties.
P51s flew 213873 sorties and had 2520 losses for a loss every 85 sorties.
That strongly suggests that the radial engined P47 was more survivable than the P51 with the liquid cooled engine but it does not prove it because there are too many variables.
At the 1944 Fighter Conference, the pilots including of course some from the UK were asked to name the power plant which inspired the most confidence. 81% of the attendees responded.
79% chose the R2800.
7% chose the Merlin.
I will still go with common sense as to the air cooled radial being more reliable just as the WW2 pilots did.

[Vincenzo]

Renrich for the Statistical digest WW II all effective combat sorties flown from fighter in ETO from 8/42 to 5/45 is 527314 so P-47 and P-51 can not flown over 637000

[buffnut453]

Amazing how in line engines despite some of their advantages, disappeared after the war with some rare exceptions (Shackleton).

Joe,

I suspect that has as much to do with service traditions and evolving technologies than anything else. For example, the USN never operated in-line pistons and continued that model throughout. The USAF consolidated onto P-51 derivatives until replaced by jet-powered airframes. The RN maintained a mix, just as they had throughout WWII, with radial engined Sea Fury, Avenger and AD-4W but piston engined Firebrand (ok, not much of an aircraft), Sea Hornet and Firefly until, again, jet-engined aircraft became more prevalent. The RAF continued with its wartime piston engines, again a mix of radial and in-line, but piston propulsion was pretty much a dead-end for anything other than derivative types (such as the Shackleton and Hornet).

Just a thought...

Cheers,
Mark

[syscom3]

The IJN CAP did engage the SBDs at Midway but their ability to interfere was lessened somewhat by the fact that they were at low altitude dealing with the VTs and had to climb to try to reach the VBs before they went into their dives.

At Midway, the Zero's had trouble with the retreating SBD's because they had run out of their 20mm ammo and were relying on the small MG's.

Plus the CAP had plenty of time to get up to the altitude of the dive bombers as there was plenty of time between the VT and VB strikes. The Zero was a fast climber. The main problem wasn't so much the altitude of the two planes, it was the Zero's were completely out of their assigned sectors, horizontally speaking, for patrolling.

[renrich]

Thanks Sys, for your clarification. If memory serves, you are the one who made me aware of "The Shattered Sword" which was a very good read. Wish I owned the book for my library.
Vincenzo, I addressed the huge number of sorties by the P47 and P51 compared to the action sorties of Navy fighters in another thread. I copied down the info on sorties in the ETO from a reliable source a number of years ago but can't remember where they came from. I can only conclude those sorties included every flight made by those fighters in the ETO which probably included training, familiarization, testing after maintenance, etc. One could say that the sortie versus losses of the P47 V P51 proves even more strongly the reliability of the air cooled radial V liquid cooled engines.

[buffnut453]

Not if the P-47s were involved in fewer engagements, and suffered concomitantly fewer combat losses, because of their shorter range. This state of affairs, at least as far as the range issue goes, was certainly the case for 8th AF escort missions. You're extrapolating a statement from a very broad data set that simply cannot be justified from the available information.

[syscom3]

Renrich; one more thing about Midway. The IJN had a very primitive system for central fighter control. Granted that the USN still had a LOT to learn, but the IJN simply was not able to handle multiple threats coming in at different altitudes and distances. You might say that the lack of an effective doctrine and radio control put the fleet defenses into a position it could not handle nor recover from.

[FLYBOYJ]

Joe,

I suspect that has as much to do with service traditions and evolving technologies than anything else. For example, the USN never operated in-line pistons and continued that model throughout. The USAF consolidated onto P-51 derivatives until replaced by jet-powered airframes. The RN maintained a mix, just as they had throughout WWII, with radial engined Sea Fury, Avenger and AD-4W but piston engined Firebrand (ok, not much of an aircraft), Sea Hornet and Firefly until, again, jet-engined aircraft became more prevalent. The RAF continued with its wartime piston engines, again a mix of radial and in-line, but piston propulsion was pretty much a dead-end for anything other than derivative types (such as the Shackleton and Hornet).

Just a thought...

Cheers,
Mark

Agree to a point. Perhaps I should have been more specific and brought in civilian operators as well. Even today, you still have newer designs (past 20 years) that have used radials. The only "modern" reciprocating engines that use coolant that I'm aware of are Rotax.

[buffnut453]

True enough, but then the primary benefit of in-line engines was streamlining to obtain faster speeds. Most post-war designs using piston engines had other performance drivers (endurance, fuel efficiency, ease of maintenance etc) with outright speed being a much lower priority. Therefore it makes sense that radials were more popular.

[renrich]

Buffnut, if you look at my earlier statements about statistics I am not claiming that the stats prove anything. I understand and have stated that there are too many variables. I said, " one could say" but I realise what you say is true. I will stick with common sense and the pilot's judgment at the Fighter Conference and the USN's judgment. I don't understand though how anyone could look at a cutaway of say a P47 or Corsair and compare it to a Spit or P51 (I have all of those) and not understand that the liquid cooled engine's cooling system creates a lot more places a single bullet can cause a shutdown of the engine. One other point is that Lindberg chose an air cooled engine at least partly because it was more reliable than a liquid cooled engine.

[buffnut453]

Renrich,

What you stated was "One could say that the sortie versus losses of the P47 V P51 proves even more strongly the reliability of the air cooled radial V liquid cooled engines." Yes, one could say that but it would be unproven and unprovable based on the info provided. Now, I don't disagree with your overall concept that there are more things to go wrong in a liquid cooled engine, nor that liquid cooling might be more vulnerable (depending on the layout of the coolant pipes relative to armour plating etc) but we need to see more comprehensive and detailed stats to prove that for sure (and, to be honest, I don't think those stats exist).

Cheers,
Mark