FAA aircraft comparative performance

[dunmunro]

You don't agree that having several inches of steel several decks higher in the ship makes a difference? Because that is why FC postions weren't heavily armored. The higher in the ship the heavy armor is, the worse damaged stability is going to be. Once the list starts, you get all that weight shifted off center.

Ships can be designed to carry weight higher, mainly by increasing the beam, decreasing the freeboard, and by careful attention to things such as ballast. The liquid loading of the torpedo defence system, for example, also plays a major role and since the liquid layer must be kept full, the ship is always adequately ballasted. However, the RN also used very advanced structural design to minimize the weight required, so that the penalty associated with the armoured hanger design was minimized. The design was further optimized by reducing the hanger side armour to provide splinter protection rather than protection against 6" gunfire and this allowed for an extra half hanger in the last 3 ships.

[Bgile]

Well, I'm sure US designers were careful with ballast, used liquid loading, and very advanced structural design. You can't carry all that weight up high without a penalty. There has to be a tradeoff somewhere. Midway had less freeboard than desired because they were trying to solve the problem by having the flight deck closer to the water. The problem becomes less severe as the ship gets larger and larger with the same deck thickness.

Obviously a battleship could be designed to carry weight higher too, and have 12" armor on the fire control positions. There is a penalty, just as with any ship including carriers.

[dunmunro]

Well, I'm sure US designers were careful with ballast, used liquid loading, and very advanced structural design. You can't carry all that weight up high without a penalty. There has to be a tradeoff somewhere. Midway had less freeboard than desired because they were trying to solve the problem by having the flight deck closer to the water. The problem becomes less severe as the ship gets larger and larger with the same deck thickness.

Obviously a battleship could be designed to carry weight higher too, and have 12" armor on the fire control positions. There is a penalty, just as with any ship including carriers.

There was a penalty in the sense that RN armoured carriers were designed with a relatively lower l/b ratio and shorter flight deck than a non-armoured carrier. However as Friedman points out the RN armoured flight deck designs used very advanced structural design, which was well ahead of its time in terms of lightweight design.

[Keith Enge]

I just can't agree that British carrier planes would have been acceptable at Midway. As I mentioned in a previous post, the Fulmar and Sea Hurricane had done poorly against Japanese carrier planes a couple of months earlier in defense of Ceylon (Sri Lanka). During the main attack, the 36 Zeroes escorting the Japanese attack force shot down almost half (19 of 42) of the defending Fulmars and Hurricanes.

As carrier planes, each had a big problem. The Sea Hurricane had only about half of the range of planes like the Martlet II and Fulmar. This precluded her use as an escort fighter. However, even if their use was limited to that of an interceptor, range is still needed because CAP use requires endurance. Otherwise, you are constantly disrupting your flight operations by cycling up new CAP. The Fulmar's problem was speed and speed is probably the primary requirement of a fighter; without speed, you can't dictate the action. As a Fulmar pilot admitted, if you didn't get your target with your first burst, you had little chance of getting another. The Fulmar's speed was abysmal; even divebombers and torpedo planes (like the Avengers just coming into service) were faster than them. By the way, some of the actions cited for the Fulmars and Sea Hurricanes (Pedestal and PQ.18) were actually months later than Midway and, by that time, Fulmars had largely been replaced as the primary FAA fighter.

Incidentally, when looking up references to the Albacore, I was unable to find a single time when Albacores, operating from a carrier, actually torpedoed another ship. They were present at Matapan but I think that Swordfish got all of those torp hits. Albacores undoubtedly got some operating from Malta but, as far as I can see, none as a carrier plane.

[dunmunro]

I just can't agree that British carrier planes would have been acceptable at Midway. As I mentioned in a previous post, the Fulmar and Sea Hurricane had done poorly against Japanese carrier planes a couple of months earlier in defense of Ceylon (Sri Lanka). During the main attack, the 36 Zeroes escorting the Japanese attack force shot down almost half (19 of 42) of the defending Fulmars and Hurricanes.

As carrier planes, each had a big problem. The Sea Hurricane had only about half of the range of planes like the Martlet II and Fulmar. This precluded her use as an escort fighter. However, even if their use was limited to that of an interceptor, range is still needed because CAP use requires endurance. Otherwise, you are constantly disrupting your flight operations by cycling up new CAP. The Fulmar's problem was speed and speed is probably the primary requirement of a fighter; without speed, you can't dictate the action. As a Fulmar pilot admitted, if you didn't get your target with your first burst, you had little chance of getting another. The Fulmar's speed was abysmal; even divebombers and torpedo planes (like the Avengers just coming into service) were faster than them. By the way, some of the actions cited for the Fulmars and Sea Hurricanes (Pedestal and PQ.18) were actually months later than Midway and, by that time, Fulmars had largely been replaced as the primary FAA fighter.

Incidentally, when looking up references to the Albacore, I was unable to find a single time when Albacores, operating from a carrier, actually torpedoed another ship. They were present at Matapan but I think that Swordfish got all of those torp hits. Albacores undoubtedly got some operating from Malta but, as far as I can see, none as a carrier plane.

Sometime ago I carefully examined the performance of the RAF/FAA defence of Ceylon with the similar Kido Butai strikes against Darwin and Midway:
Here's the stats:
Allied fighter Kills/Losses/sorties and Sortie loss %:

Midway: F2A/F4F: 2/15/24/62%
Darwin: P40 ~1/10/11/~90%
Ceylon: Hurricane/Fulmar 10/30/71/42% (two attacks April 5/9)

The Sea Hurricanes also had a better kill loss ratio during PEDESTAL than the Martlets.

The Sea Hurricane I/II/F4F-4 range, according to the FAA, was 480nm/400nm/600nm. With DTs the Sea Hurricane I/II range extended to 890/790nm and USN testing showed 900nm/1100nm for the F4F-4 with one or two DTs but these used different criteria and so are not strictly comparable. I've already posted this at the beginning of the thread but to make things more readable here it is again:

Speed:
Sea Hurricane IB: (normal/combat) 235/250 knts at SL, 259/285 knts at 11000ft and 268 knts at 18000ft (combat est with 12lb boost and hundred octane fuel. 14 or 16lb boost which was permitted in mid 1942 would add another 5-10 knots )
Sea Hurricane IIC 280 knts at 13500ft, 298 knts at 22000ft (these may be at the combat rating)
Fulmar: 230 knts at 1750ft and 231knts at 9600ft (These figures are probably not at the combat rating of the engine and I would estimate the combat rating to give another 10-15 knts at 1750/9600ft) The Fulmar II's Merlin 30 engine was highly optimized for low altitude performance and was well suited to escorting low altitude strikes, unlike the F4F-4.
F4F-4: (normal/combat) 242/250 knts at 1750ft and 261/264 knts at 9600 ft from official USN testing. RAE testing gives maximum speed as 286mph at 4000ft and 298 mph at 15000ft. Official USN data shows 310mph at 15000 ft and 320mph at 18800ft.
SBD-3: 201 knts at SL, 211 knts at 5000ft, 204 knts at 9600ft and 217 knts at 16000ft. (Engine had no additional combat rating )

Climb:
Sea Hurricane 1B: (normal/combat) 2250fpm/3100fpm(est - 14 or 16lb boost would add 10-20%) at SL.
Sea Hurricane IIC: 2010/3300fpm(est at 14lb) at SL. 9.1min to 22k ft
Fulmar II 1320/2000 (est) FPM at SL and 7min to 10k ft.(Friedman 7min to 10K ft which = ~1400fpm average) 12min to 15k ft (various) (Continuous rating was 9.75lb boost at 2850 RPM, combat rating was 12lb at 3000RPM up to 6000ft giving another 25% power and I would estimate that at the 5min combat rating that climb to 15k ft would be about 9min)
F4F-4 2200/2480(normal/military USN testing) at SL, 1760/2580fpm at SL(normal/combat RAE testing), 2030/2120fpm at 6k ft (normal/military USN testing), 1650/1650fpm at 13k ft (USN testing) and 5.6min to 10Kft (USN testing) 9.4 min to 15k ft (RAE testing). 12.4min to 20k ft (USN testing) The combat/miltary rating does not provide a great increase in climb performance above 3000ft and so I would estimate about a 20-10% reduction in time to 10 and 20k ft respectively at the military rating.
SBD-3 (clean with max internal fuel) 1190fpm at SL and 9min to 10k ft.

Swordfish and Albacores were both present at Matapan but the Albacores from Formidable flew the majority of the sorties and probably scored hits in a similar proportion to their numbers. Wikipedia states:

A second sortie surprised the Italians at 15:09. Lieutenant-Commander Dalyell-Stead flew his Albacore to 1,000 metres from Vittorio Veneto, hitting her outer port propeller and causing 4,000 tons of water to be taken on.

To the Italians, any biplane TB was a "Swordfish".

Regarding Midway, if the USN was using FAA aircraft they would have probably changed their tactics to suit the characteristics of the aircraft:
Strengths:
Fulmar: high speed recon with DT/low altitude escort with DT/Medium altitude DB/GB strike with either one 500lb bomb or 2 x 250lb and one DT.
Albacore: Long range recon with ASV/day/night TB strike with ASV/ ASV assisted daylight medium altitude DB strike with up to 4 x 500lb bombs, or longer range with 2 x 500lb and DT
Sea Hurricane: CAP/point defence/long range medium altitude escort with DTs

Personally I would have made the first strikes with the Albacore and Fulmar in the DB mode and reserved the Albacore for night TB strikes (this was an option that the USN could not use with the TBD and it was forced into daylight low altitude TB strikes).

[Bgile]

Isn't it possible the DB attacks would have failed because the pilots had no experience in that mode of operation? Also, a shallower dive is not as accurate. Did either of these aircraft ever actually dive bomb a ship at sea?

When were drop tanks introduced? I don't think US aircraft had them at Midway.

[Keith Enge]

Bgile makes a good point. The SBDs sank four carriers. The chances that British DBs would hit anything much less sink them were slim. Neither the RAF nor FAA favored divebombers; in fact, except for brief enlightened periods, they actively opposed them. After the Skua, they didn't really have any for the rest of the war if you discount the lend-lease Vengeances used in Burma. Instead, they used planes like the Albacore that were only capable of relatively shallow dives or later fighter-bombers like the Typhoon and then Tempest. The FAA's divebombing was done by their lend-lease Avengers (Tarpons); that "divebombing" should be in quotes since it too was too shallow to be real divebombing.

My database of WWII ships includes the causes of ship losses so I had it search for British divebombing kills. The list of successful British divebombing of ships is very short. The only warship sunk that was larger than a destroyer was Konigsberg, the German CL. She was, however, a special case. When sunk by Skuas (land-based), she was tied to a dock and only her fore guns could bear on the attackers. Furthermore, damage by the Norwegians had reduced her forward AA to a mere two 20mm guns. Then, after she was hit, she still took three hours to sink and the sinking was the result of fire and flooding that couldn't be controlled because that same earlier Norwegian damage had destroyed fire mains and pumps.

So if we discount Konigsberg, any other targets stationary in port, and ships smaller than DDs, we are left with a mere six ships. Four of these ships were much later in the war. Two Italian DDs, Lampo and Pancaldo, were sunk in April 1943 by British planes; however, I believe that they were lend-lease Warhawks (P-40) and so weren't divebombers. TA.15 (ex-small Italian DD Crispi) was sunk in March 1944 by air-launched rockets (plane type unknown by me but RAF not FAA, could be Swordfish but probably Beaufighters, not divebombers in any case). Z24, the German DD, was sunk in August 1944, again by the RAF and not by divebombing.

That leaves us with two Italian DDs, Borea and Sauro, sunk in September 1940 and April 1941, respectively. Both were sunk by Swordfish although, at least in the later case, they were currently land-based. Even if we consider the Swordfish's type of bombing attack to be divebombing, that is a rather meager record for six years of war. By the way, I know that I have discounted things like the U-boats sunk by FAA Swordfish but, once again, that wasn't divebombing (depth charges or, later, rockets).

So, like Bgile, I wouldn't want to trust British divebombers in the pivotal battle of the Pacific war. For kicks, I also had the database search for ships sunk by US bombs. It found 73 Japanese victims alone, DD or larger. Some of these were sunk in combination with other ordnance so I then had it find the victims of only bombs, no torps or anything else added. It still found 49. Some of these weren't divebombing. A very few were high-level bombers and some were skip-bombing by the USN or USAAF but the remaining total was much larger than British total and was achieved in only four years in one theater.

[dunmunro]

Isn't it possible the DB attacks would have failed because the pilots had no experience in that mode of operation? Also, a shallower dive is not as accurate. Did either of these aircraft ever actually dive bomb a ship at sea?

When were drop tanks introduced? I don't think US aircraft had them at Midway.

If the USN was equipped with the Fulmar II, Albacore and Sea Hurricane it seems likely that they would have trained to use the aircraft in each of its possible mission modes. It is true that a Fulmar with a 500lb bomb was probably less accurate than an SBD with a 500 or 1000lb bomb anda Fulmar with 2 x 250lb would not have been as effective. A pure Fulmar DB/GB attack at Midway with the same numbers of aircraft as SBD attacks would probably have resulted in one or more IJN carriers surviving the battle, albeit still badly damaged but a total commitment of the Fulmar and Albacore to DB attacks would probably have been as or more effective.

At Taranto about 1/3 of the Swordfish sorties were flown as DBs.The Albacore was used extensively as a DB, but not usually against naval targets because typically the torpedo was more efficient; KM or RM capital ships could not be sunk or slowed down with 500lb bombs. However, the only naval targets where this was typically not the case was against enemy carriers and the RN never had the opportunity to attack these targets . Friedman's American & British aircraft carrier development, 1919-1941 details how the RN decided that the best way to disable/destroy IJN CVs was with DBs and this led directly to the development of the Swordfish, Skua, Albacore and Barracuda which had dual TB/DB capability. The Fulmar's contract specs had DB/GB capability written into it, but this was not really feasible for the Mk1 due to engine limitations and to fighter capability as a priority as neither the KM or RM had any CVs. However with the MKII, increased engine power made a secondary DB strike capability possible as well as the use of a DT.

The F4F-4 had DT capability as part of the contract specs but I don't know if they were used during the Midway operation (reviewing action reports it seems unlikely). Hurricanes were used with DTs as early as May 1941 during the Battle for Crete. Sea Hurricanes did not use DTs during HARPOON or PEDESTAL but some did use them when used as catapult fighter against FW-200 attacks. As I mentioned earlier the Fulmar II trialled DTs in Oct 1941.
This report from Sept 1942 details F4F-4 performance with one or two DTs:
http://www.wwiiaircraftperformance.org/ ... -02135.pdf

[dunmunro]

Bgile makes a good point. The SBDs sank four carriers. The chances that British DBs would hit anything much less sink them were slim. Neither the RAF nor FAA favored divebombers; in fact, except for brief enlightened periods, they actively opposed them. After the Skua, they didn't really have any for the rest of the war if you discount the lend-lease Vengeances used in Burma. Instead, they used planes like the Albacore that were only capable of relatively shallow dives or later fighter-bombers like the Typhoon and then Tempest. The FAA's divebombing was done by their lend-lease Avengers (Tarpons); that "divebombing" should be in quotes since it too was too shallow to be real divebombing.

The Swordfish, Albacore and Barracuda were capable of vertical DB attacks when using wing mounted ordnance, but this was typically restricted to 500lb bombs (Barracudas used 2 x 600lb mines as Anti-personnel weapons against Tirpitz), and the odds of these aircraft hitting a target in DB mode would be identical to the SBD. The Swordfish, Fulmar, Albacore and Barracuda could dive bomb with a centreline ordnance load but were restricted to 60deg or shallower dives since they did not have a bomb crutch like the Skua or SBD. The Skua was used as a DB against RM CAs but a 500lb SAP bomb has to be dropped at high altitude to penetrate an armoured deck and this caused the Skuas to drop high and miss and thus caused the FAA to prefer TB attacks against armoured warships.

AFAIK, FAA Tarpon/Avengers never attacked a naval target other than submarines.

[lwd]

I haven't seen much to indicate that the USN used drop tanks at this point in the war. Likewise if the fighters were sent as escorts they didn't tend to carry bombs. Especially if you think you'll encounter enemy fighters bombs are rather a waste as you'll need to jetison them anyway and have burned up more fuel getting to that point.

If one thinks of the Fulmar as a high performance SBD with a reduced bomb load, then one gets a better idea of how it was originally intended to be used. If the Fulmar meets no opposition then it can carry out its DB function and could then actually pull any CAP away from the Albacore DBs/TBs trailing behind.

If however it does meet opposition it is at a signficant dissadvantage until the bombs can be jettisoned and even then it's going to have less fuel. At the time of Midway I believe you would want your escort fighters to be planning on acting as escorts.

[dunmunro]

I haven't seen much to indicate that the USN used drop tanks at this point in the war. Likewise if the fighters were sent as escorts they didn't tend to carry bombs. Especially if you think you'll encounter enemy fighters bombs are rather a waste as you'll need to jetison them anyway and have burned up more fuel getting to that point.

If one thinks of the Fulmar as a high performance SBD with a reduced bomb load, then one gets a better idea of how it was originally intended to be used. If the Fulmar meets no opposition then it can carry out its DB function and could then actually pull any CAP away from the Albacore DBs/TBs trailing behind.

If however it does meet opposition it is at a signficant dissadvantage until the bombs can be jettisoned and even then it's going to have less fuel. At the time of Midway I believe you would want your escort fighters to be planning on acting as escorts.

At Phillipine Sea, in June 1944, the USN escort fighters were mostly (if not all) equipped with bombs and DTs. At Midway the TB strikes were not intercepted prior to attacking because the IJN CAP was drawn down low to defeat the strikes from Midway. Since the IJN did not have radar it was difficult for them to detect medium altitude strikes that were flying above the layer of broken cloud. If the Fulmars and Albacores are used as DBs, a Fulmar DB attack just prior to the Albacore DB attack should pull any cap down to meet the Fulmars and thus clear the way for the Albacores. If the entire strike is committed at a medium altitude DB attack, then it might be possible for a small number of DT equipped Sea Hurricanes to act as top cover for the strike, and so reduce the probability of the Fulmars being forced to jettison their bombs unless the strike is intercepted en-mass.

[Keith Enge]

dunmunro, I need a clarification. Your "what if" had US carriers using British planes at Midway. My question is what pilots would be used? Would they be FAA pilots or US pilots and which navy's attack doctrine would be used? I assume that US carrier flight deck operations would still be used. Also, would the US carriers be separated as per their current dispersal doctrine rather than concentrated as the Royal Navy probably would have done? Finally, are we just talking about carrier planes or are the land-based planes on Midway included too?

As a point of interest, in late 1941 and early 1942, the FAA was deficient in experienced attack plane pilots. Some unprofitable raids on North African ports and especially the disastrous Kirkenes and Petsamo raids in the North Cape had resulted in significant losses. The losses in Operation Cerberus didn't help either. Replacement pilots were being sent to the RAF but few to the FAA and, of course, those replacements lacked experience.

[dunmunro]

dunmunro, I need a clarification. Your "what if" had US carriers using British planes at Midway. My question is what pilots would be used? Would they be FAA pilots or US pilots and which navy's attack doctrine would be used? I assume that US carrier flight deck operations would still be used. Also, would the US carriers be separated as per their current dispersal doctrine rather than concentrated as the Royal Navy probably would have done? Finally, are we just talking about carrier planes or are the land-based planes on Midway included too?

As a point of interest, in late 1941 and early 1942, the FAA was deficient in experienced attack plane pilots. Some unprofitable raids on North African ports and especially the disastrous Kirkenes and Petsamo raids in the North Cape had resulted in significant losses. The losses in Operation Cerberus didn't help either. Replacement pilots were being sent to the RAF but few to the FAA and, of course, those replacements lacked experience.

Kirkenes and Cerberus were certainly defeats for the FAA, but the losses (~20 aircraft and most of their aircrew) were not really that serious in the grand scheme of things. IMHO, the more severe FAA losses were the loss of Courageous, with her aircraft and many personnel, Glorious, with almost all personnel and Ark Royal with all her aircraft. The damage to Illustrious in Jan 1941 also involved the loss of about a dozen aircraft or so, and these sunk or damaged CVs involved the loss of ~120 aircraft and many air and maintenance personnel.

However for the sake of this scenario, I think we can assume that the US carriers are using USN doctrine and USN pilots since I want to explore the capability of FAA aircraft that were in service as of mid 1942, rather than the differences in USN and FAA doctrine and/or CV design. However, we also have to recognize doctrine is likely to be modified to take advantage of different aircraft capabilities and so, for example, the USN might not launch daylight TB strikes with their Albacores but either hold them back for a night strike or use them in a DB attack mode, since this might be more cost effective and survivable than daylight TB strikes, even if the Albacores are using RN torpedoes, given that the Albacore and TBD would probably face similar loss rates in the face of determined fighter opposition.

[lwd]

... At Phillipine Sea, in June 1944, the USN escort fighters were mostly (if not all) equipped with bombs and DTs.

Source PLS. In any case at this point the US was expecting considerably less oppositon from Japanese CAP at least in porportion to the strike.
Looking through http://www.cv6.org/1944/marianas/marianas_3.htm I see no mention of escort fighters dropping bombs or carrying drop tanks although there is a mention of one of the fighters strafing a Japanese CV.
My impression is that if they carried bombs during this battle it was for the strikes vs Japanese air fields.

At Midway the TB strikes were not intercepted prior to attacking because the IJN CAP was drawn down low to defeat the strikes from Midway.

No. The TB's were intercepted prior to attack and that's where many of the losses occured. The dive bombers where not intercepted because they were not detected much at all prior to pitch over and the CAP was down on the deck with the torpedo bombers.

If the stike comes in as a single package it significantly increases the chance of it being detected and intercepted. In any case it's best not to plan on being able to reach your drop points undetectd.

[dunmunro]

... At Phillipine Sea, in June 1944, the USN escort fighters were mostly (if not all) equipped with bombs and DTs.

Source PLS. In any case at this point the US was expecting considerably less oppositon from Japanese CAP at least in porportion to the strike.
Looking through http://www.cv6.org/1944/marianas/marianas_3.htm I see no mention of escort fighters dropping bombs or carrying drop tanks although there is a mention of one of the fighters strafing a Japanese CV.
My impression is that if they carried bombs during this battle it was for the strikes vs Japanese air fields.

At Midway the TB strikes were not intercepted prior to attacking because the IJN CAP was drawn down low to defeat the strikes from Midway.

No. The TB's were intercepted prior to attack and that's where many of the losses occured. The dive bombers where not intercepted because they were not detected much at all prior to pitch over and the CAP was down on the deck with the torpedo bombers.

If the stike comes in as a single package it significantly increases the chance of it being detected and intercepted. In any case it's best not to plan on being able to reach your drop points undetectd.

On June 20 1944 at least 37 of the USN fighters were equipped with GP bombs while 15 others had an unspecified bomb load:
http://dreadnoughtproject.org/friends/d ... ea%206.pdf (page 14)
Titans of the Seas, P344 mentions an attack on Zuikaku by bomb carrying Hellcats during the USN strike on June 20 1944. No doubt some of the Hellcats were forced to jettison their bombs to engage fighters but some did carry out bombing attacks.

At Midway the TB strikes were not intercepted prior to attacking because the IJN CAP was drawn down low to defeat the strikes from Midway.

Of course, I meant to say DBs not "TBs".
At Midway the USN was well aware that a large proportion of the IJN air strength was attacking Midway, and that Midway strikes were distracting IJN CAP.