An early 2-engined carrier based aircraft - worth the effort?

[Shortround6]

There were real-world examples of sizable aircraft that were handled more or less without problems at the early war carriers. Neither Val nor Dauntless were sporting much of the folding wings (Val's wing tips were folding). Sea Hurricane, F4F-3 again are both sizable and their wings don't fold. Zero's wing tips fold, some variants don't even have that much.
The big Avenger was operating from Independence CVLs. The useful twin does not have to be any bigger than SNCASE SE.100 or Gloster F.9/37.

Useful or Better than? The twin has to be more than useful, it has to be better than the single engine plane as you will have fewer of them and they will require more maintenance.

The Val and Dauntless had big foot prints ( took up a lot of deck space) but they were light (relatively) and had low take-off and landing speeds. An SBD-3 in combat condition ( armor and self sealing tanks) went just about 9000lbs including a 1000lb and had a stalling speed of about 76mph with the bomb. Wing loading was 27.8lbs per sq ft and stall and wing loading were about the same with 260 gallons of fuel aboard with no bomb for the scout mission.
A TBM-3 Avenger has a Max take-off weight of 18,100lbs BUT that is for catapult. Arrested landings and landings on "average" airfields were supposed to be restricted to 15,500lbs. At which weight the Avenger with it's big wing had a 31.63lb sq ft wing loading.

We've seen that Avenger did not met several requirements, yet it was accepted for production. Seems like Navy (Navies?) was capable to revise requirements in order to acquire themselves a next-gen aircraft?

Kind of depends on requirement, dropping the 30,000ft ceiling for a torpedo bomber wasn't really giving up much. Not quite meeting speed or range requirements is also not that bad a loss depending on how much they are off. Failing to meet the take-off and landing requirements for a land plane are one thing, failing to meet them with a carrier plane are another. Adding flight deck length is a LOT harder than tree cutting or extending runways. Plus you have a limited number of carriers and a lot of airfields.

The excessive weight difference between a fighter and a torp bomber can be slightly addressed with gun weaponry layout - install two fixed HMGs, attach 4 HMGs in a fairing/tray/pod instead of torpedo. British can have 4 fixed LMGs, plus 6 detachable.

Sounds better in theory than practice. Just like the Japanese at Midway, whatever you have loaded on the aircraft will be the wrong weapon when the enemy appears within range
US Navy had all kinds of weight schemes for F4F and F4U aircraft when they were used as "bombers" with .50 cal guns taken out (leaving the F4F with just two guns) that were NEVER APPARENTLY used in combat.

As for the bulk vs. speed - seems like both Gloster and SNCASE were capable for greater speeds than Zero, S.Hurri or F4F, Firefly, let alone Fulmar. Despite the size.

The Gloster some how managed to lose 30mph once the initial set of engines were taken out. It also was never flown with guns or armor was it? I am having a hard time figuring out how a plane that was bigger and heavier than the Whirlwind is going to out climb it using about the same power engines. The boom and zoom only works once or twice if the enemy fighters can out climb you.

AS for the SNCASE Se 100, do you really want to try and land this on a carrier?

and with a wing 62% of the size of the one on the Avenger and about the same weight airplane you know it is coming in faster.

With the power similar to early P-38, Ki-45 or Bf-110, it can do both.

No, it can't. If you are carrying the torpedo you are not carrying fuel. SBD could carry a 1000lb bomb and 100 gallons of fuel, a 500lb bomb and 140 gallons or 260 gallons and no bomb. the US was cursed not only with a torpedo that didn't work well ( at all?) but one that weighed 2200lbs. Carrier strike planes need around 200-250 miles radius of action. P-38s could barely manage that without drop tanks.

 

[tomo pauk]

Useful or Better than? The twin has to be more than useful, it has to be better than the single engine plane as you will have fewer of them and they will require more maintenance.

Indeed, it does need to be better. It need to have 400 rounds for all of it's six HMGs, it need to climb good even when fully navalized in the fighter role. It need to be decently fast. It need to be able to haul a big bomb or a torpedo at decent speed, but not at the cost of being unarmored/unprotected. Once it carries 4 cannons, the performance will still need to be acceptable.
In order to have an aircraft capable to do all of this, we need a 2000 HP engine aircraft. Since there was a lack of such things in the 1st half of war, the 2x900-1200 HP engines will be needed, with their inherent shortcomings.

The Val and Dauntless had big foot prints ( took up a lot of deck space) but they were light (relatively) and had low take-off and landing speeds. An SBD-3 in combat condition ( armor and self sealing tanks) went just about 9000lbs including a 1000lb and had a stalling speed of about 76mph with the bomb. Wing loading was 27.8lbs per sq ft and stall and wing loading were about the same with 260 gallons of fuel aboard with no bomb for the scout mission.
A TBM-3 Avenger has a Max take-off weight of 18,100lbs BUT that is for catapult. Arrested landings and landings on "average" airfields were supposed to be restricted to 15,500lbs. At which weight the Avenger with it's big wing had a 31.63lb sq ft wing loading.

All fair. I was trying to point out that a twin with folding wings should not use more space than many of useful ww2 CV aircraft.

Kind of depends on requirement, dropping the 30,000ft ceiling for a torpedo bomber wasn't really giving up much. Not quite meeting speed or range requirements is also not that bad a loss depending on how much they are off. Failing to meet the take-off and landing requirements for a land plane are one thing, failing to meet them with a carrier plane are another. Adding flight deck length is a LOT harder than tree cutting or extending runways. Plus you have a limited number of carriers and a lot of airfields.

Again okay. The aircraft designer will need to integrate in hi's design the high-lift devices, and resort to a decently sized wing in order to meet take off and landing requirements.

Sounds better in theory than practice. Just like the Japanese at Midway, whatever you have loaded on the aircraft will be the wrong weapon when the enemy appears within range
US Navy had all kinds of weight schemes for F4F and F4U aircraft when they were used as "bombers" with .50 cal guns taken out (leaving the F4F with just two guns) that were NEVER APPARENTLY used in combat.

Thanks for pointing that out. We can easily imagine about any Western fighter doing that. The FAA aircraft with detachable guns will be able to protect the convoy with all it's aircraft, and later during the day maybe attack something with big bombs, that would replace a pair of cannons. IJN or USN aircraft will be able to do the same, my guess is that removing 4 individual HMGs will consume far more time than unbolting the pod/tray.

The Gloster some how managed to lose 30mph once the initial set of engines were taken out. It also was never flown with guns or armor was it? I am having a hard time figuring out how a plane that was bigger and heavier than the Whirlwind is going to out climb it using about the same power engines. The boom and zoom only works once or twice if the enemy fighters can out climb you.

Data about the Gloster is a well 'camouflaged' one, especially the talk about the '900 HP Taurus'? Whirly was offering some 30 mph when both were flying with Peregrines, no wonder since it was a smaller aircraft.

AS for the SNCASE Se 100, do you really want to try and land this on a carrier?

and with a wing 62% of the size of the one on the Avenger and about the same weight airplane you know it is coming in faster.

I admit that SNCASE will be a lousy CV aircraft. The excessive weight of the 5 cannons and ammo were adding at least 800 lbs to the all-up weight, such armament weight will not be carried if the plane is in returning from the bombing sortie. It could use a bigger wing, though.

No, it can't. If you are carrying the torpedo you are not carrying fuel. SBD could carry a 1000lb bomb and 100 gallons of fuel, a 500lb bomb and 140 gallons or 260 gallons and no bomb. the US was cursed not only with a torpedo that didn't work well ( at all?) but one that weighed 2200lbs. Carrier strike planes need around 200-250 miles radius of action. P-38s could barely manage that without drop tanks.

SBD did not have the choice, the 1200 HP engine rarely offers it.
Late P-38s were capable for a radius of 250 miles at 10000 ft, with 2 x 1600 lbs of bombs, and with 20 min of air-to-air combat, internal fuel only (410 US gals), all of the cruising performed at 210 mph IAS (~250 mph at 10kft), with 30 min of reserve on minimum cruise power. The P-38 can lug a 1000-2000 lb worth of a bomb, and a 310-75 US gal drop tank in the same time - no SBD was ever capable to do that, no matter how long a runaway was long.

 

[fastmongrel]

If whats wanted is a faster longer ranged Avenger how about doing some work on slimming down that rather porky fuelage. Did it really need a bomb bay, bombardier and powered turret why not a shallower 2 man fuselage and external or semi external torpedo and bombs.

 

[Shortround6]

Indeed, it does need to be better. It need to have 400 rounds for all of it's six HMGs, it need to climb good even when fully navalized in the fighter role. It need to be decently fast. It need to be able to haul a big bomb or a torpedo at decent speed, but not at the cost of being unarmored/unprotected. Once it carries 4 cannons, the performance will still need to be acceptable.
In order to have an aircraft capable to do all of this, we need a 2000 HP engine aircraft. Since there was a lack of such things in the 1st half of war, the 2x900-1200 HP engines will be needed, with their inherent shortcomings.

two 1000hp engines do not equal a single 2000hp engine. Kelly Johnson when designing the P-38 figured two 1000hp engines equaled a single 1500hp engine. He may have been a bit off but when the Helldiver, Avenger, Brewster Bermuda and the Vought/Consolidated Seawolf were designed Wright had the 1500-1600hp R-2600 on offer (improved to 1700hp on initial production versions and 1900hp on late versions), The Vought design, being a United Aircraft company, used the R-2800.
If your design pre-dates this aircraft (and it would almost have to in order to see wide spread service in 1942 let alone RN service in 1941) then the 1200hp engines tend to disappear design wise. They can show up for production versions but prototypes would be flying with 900-1050 engines.

All fair. I was trying to point out that a twin with folding wings should not use more space than many of useful ww2 CV aircraft.

They may not take-up more deck space but handling heavier aircraft can be a problem.

Picture of the Saratoga with fixed wing Biplanes landing aircraft. ALL those aircraft have to be moved to the back half of the deck to start taking off.

Saratoga moving Hellcats(?) to the front of the the deck to prepare for landing (?). they are running the engines to move the planes.

http://upload.wikimedia.org/wikiped...44.jpg/1024px-USS_Saratoga_(CV-3)_1943-44.jpg

Saratoga with fixed wing Dauntless

Lets double the number of whirling propellers in that mess

One of the Saratoga's elevators

Saratoga's forward elevator early in her career, it was later changed to a rectangular elevator.

Again okay. The aircraft designer will need to integrate in hi's design the high-lift devices, and resort to a decently sized wing in order to meet take off and landing requirements.

You seem to be enamored with hi-lift devices.

Avenger coming in for landing:

http://upload.wikimedia.org/wikiped...rumman_TBM_Avenger,_Chino,_California_(1).jpg

A fair amount of flap area. and Avengers did use a small area of fixed slots to help with aileron control at low speed.

High lift devices can help but since the existing planes were already using hi-lift devices of some sort even if not quite as good how much improvement you are going to get is in question. Also please remember that the slats/slots if extended over more of the wing for more help with landing and take-off add drag which hurts speed/cruise. Also please remember that slats/slots are not "magic", they ONLY work when the angle of attack of the wing exceeds 13-15 degrees.

I am not sure you want an Avenger or twin engine aircraft trying to operate at angles like this

BTW the Fiesler Storch had been demonstrated at the Cleveland air races in 1937 (?) and the Army had issued a specification for a similar aircraft in 1938 resulting in the above Ryan Dragonfly and the contract winning Vultee/Stinson Vigilant

Which first flew in the summer of 1940.

SBD did not have the choice, the 1200 HP engine rarely offers it.
Late P-38s were capable for a radius of 250 miles at 10000 ft, with 2 x 1600 lbs of bombs, and with 20 min of air-to-air combat, internal fuel only (410 US gals), all of the cruising performed at 210 mph IAS (~250 mph at 10kft), with 30 min of reserve on minimum cruise power. The P-38 can lug a 1000-2000 lb worth of a bomb, and a 310-75 US gal drop tank in the same time - no SBD was ever capable to do that, no matter how long a runaway was long.

True but now lets try to figure a 1941 P-38 with 1150hp engines instead of 1325-1425 (and up) engines of the later P-38s. After all the figures I gave you were for an SBD-3 with a Wright R-1820-52 engine with 1000hp for take-off, Production started early in 1941, I believe the SBD-4 kept the same engine and the 1200hp engine only became available with the SBD-5.

 

[pinsog]

The F5F is beginning to look better and better to me. If equiped with the P&W 1830 1200 hp engine, I think it could have been a real performer. Even if top speed was only 375 mph or so, it would be faster than the Zero and substantially faster than the Wildcat but hopefully available at the beginning of the war. Essentially it would have had F6F performance, but earlier.

 

[tomo pauk]

If whats wanted is a faster longer ranged Avenger how about doing some work on slimming down that rather porky fuelage. Did it really need a bomb bay, bombardier and powered turret why not a shallower 2 man fuselage and external or semi external torpedo and bombs.

Not particularly the faster Avenger, more likely a multi-role CV airplane.

two 1000hp engines do not equal a single 2000hp engine. Kelly Johnson when designing the P-38 figured two 1000hp engines equaled a single 1500hp engine. He may have been a bit off but when the Helldiver, Avenger, Brewster Bermuda and the Vought/Consolidated Seawolf were designed Wright had the 1500-1600hp R-2600 on offer (improved to 1700hp on initial production versions and 1900hp on late versions), The Vought design, being a United Aircraft company, used the R-2800.
If your design pre-dates this aircraft (and it would almost have to in order to see wide spread service in 1942 let alone RN service in 1941) then the 1200hp engines tend to disappear design wise. They can show up for production versions but prototypes would be flying with 900-1050 engines.

I was pointing out to the fact that it took R-2800 aboard to have an aircraft capable to be a good fighter and useful bomber. The 2x~1000 HP engines will indeed power the prototypes. I don't dream 'my' aircraft will be anywhere close to 400 mph, like P-38 or F4U, rather to 330-360 mph.

They may not take-up more deck space but handling heavier aircraft can be a problem.

Picture of the Saratoga with fixed wing Biplanes landing aircraft. ALL those aircraft have to be moved to the back half of the deck to start taking off.

Saratoga moving Hellcats(?) to the front of the the deck to prepare for landing (?). they are running the engines to move the planes.

Saratoga with fixed wing Dauntless

Lets double the number of whirling propellers in that mess

One of the Saratoga's elevators

Saratoga's forward elevator early in her career, it was later changed to a rectangular elevator.

1st, let me thank you for the pictures.
The Saratoga can operate the fixed wing F4Fs. What ever effort was needed for moving the Avengers and the like, it will be needed for the twins.

You seem to be enamored with hi-lift devices

.
Seems like they were worth it.

Avenger coming in for landing:

A fair amount of flap area. and Avengers did use a small area of fixed slots to help with aileron control at low speed.

High lift devices can help but since the existing planes were already using hi-lift devices of some sort even if not quite as good how much improvement you are going to get is in question. Also please remember that the slats/slots if extended over more of the wing for more help with landing and take-off add drag which hurts speed/cruise. Also please remember that slats/slots are not "magic", they ONLY work when the angle of attack of the wing exceeds 13-15 degrees.

IIRC you were saying that flaps like that were more air brakes, than real flaps? The slats were not that draggy items, but maybe extra several sq ft of wing is a better asset? Anyway, seems like people at Grumman were of opinion that slats were worth it, even if it's a fixed variety.

I am not sure you want an Avenger or twin engine aircraft trying to operate at angles like this

Seems like this Avenger was incoming at a good angle of attack? The angle between the Avenger being in 3-point position and in horizontal 'state' was already 11°25'. Add the wing incindence - 2-3 deg? - and we're already at the 13-14 deg worth of angel of attack.
This particular Avenger was landing on an escort carrier.

You will note that Ryan Dragonfly was also featuring fowler type flaps, full span for a good measure. Seems like they were wort it, quote from Wikipedia:
At gross weight, the YO-51 could, without flaps, take off after a run of 400 feet, while with full flaps the take off run would be only 75 feet, or just four feet more than twice its own length.[4] The Dragonfly was capable of maintaining level flight at speeds as low as 30 miles per hour (48 km/h),[5] and was claimed as being capable of landing in a distance shorter than the length of the aircraft itself.[6

True but now lets try to figure a 1941 P-38 with 1150hp engines instead of 1325-1425 (and up) engines of the later P-38s. After all the figures I gave you were for an SBD-3 with a Wright R-1820-52 engine with 1000hp for take-off, Production started early in 1941, I believe the SBD-4 kept the same engine and the 1200hp engine only became available with the SBD-5.

I have no problems with early P-38s with 2x1150 HP for the take off - they were cleared to take off wit two 300 gal tanks. With a 1000 (1100?) lb bomb and a 150 gal tank, they were capable for range of 670-1300 miles, depending on speed, without dropping the attached cargo.

added: this one is also making a steep landing, with substantial AoA: http://upload.wikimedia.org/wikipedia/commons/e/ee/Grumman_Avenger_landing_on_HMS_Ravager_A21290.jpg

 

[Glider]

The F5F is beginning to look better and better to me. If equiped with the P&W 1830 1200 hp engine, I think it could have been a real performer. Even if top speed was only 375 mph or so, it would be faster than the Zero and substantially faster than the Wildcat but hopefully available at the beginning of the war. Essentially it would have had F6F performance, but earlier.

I admit that I find the F5F to good to be true. The RAF had its fingers burnt a number of times with performance figures that had nothing to do with the real life ability of the aircraft to take part in combat. The P39 and the B17C as supplied being two good examples. Do we know what configuration these figures were achieved with. Did the aircraft have armour, self sealing fuel tanks, fully loaded weapons, full tanks when making these figures, or were they light weight stripped down aircraft aiming for headlines.

 

[tomo pauk]

What were Bell and Boeing advertised, that P-39 and B-17 were not capable to do?

Here is the SAC table for the XF5F, it does have no weapons aboard:

 

[wuzak]

You seem to be enamored with hi-lift devices.

Avenger coming in for landing:

The Avenger seems to have split flaps.

Is it wrong to assume that slotted flaps or double slotted flaps would give better lift results?

With slotted and double slotted flaps the actuating mechanisms can cause additional drag.

However, a twin engined aircraft should be able to hide those mechanisms in the fuselage/nacelle to minimise the drag increase.

The A-26 had double slotted flaps, though it was a bit later than the twin proposed here.

 

[Shortround6]

Slotted flaps may have given better results although slotted flaps don't necessarily move backward and increase wing area like Fowler flaps do.

Just so we are all on the same page

and

Again please note the angle/s of attack where the device gives the most lift ( there is a reason those modern jets come in so nose high).

far from ignoring slots/slats there was quite a fad for them in late 30s and 1940/41 before they figured out that many aircraft never operated at the angles of attack where they were effective. Many designers went for them not so much for lift which would require them over a fair percentage of the wing but just in front of the ailerons in order to maintain aileron control near or at stall and prevent wing dipping or spinning. May have used them in place of wash out? Since they were a Handley Page invention ( with a German) they were used on Hampdens I believe, the first 50 or so Halifax's (again, you don't want 4 engine bombers having angles of attack of 15 degrees or more) the Lockheed 14,18 and military derivatives and some (?) B-24s among other aircraft. Whirlwinds had their movable slats wired shut.
Perhaps some companies didn't want to pay royalties to Handley Page?

The A-26 was the first aircraft to enter service with double slotted flaps ( I don't know about experimental aircraft)

Picture of a P-38 with the Fowler flaps down

Now a problem you have with carrier planes is not only do you have to have a low stalling speed but the plane has to be capable of accelerating away and climbing in case of a wave-off or missed hook if the deck is clear, If the deck is not clear and the crash barrier is up then it doesn't matter ( black humor) so your high lift devices cannot cause excessive drag or major pitch changes as they are retracted, they might want a fairly quick retraction time too.
Take a look at some of the lift to drag ratios with some of the high lift devices, they also have some pretty high drag ( or low lift in relation to drag) when operating near their max.

 

[Glider]

What were Bell and Boeing advertised, that P-39 and B-17 were not capable to do?

Here is the SAC table for the XF5F, it does have no weapons aboard:

Thanks for this. I notice that the XF5F has a climb to 10,000 ft of 4.2 mins but it has been stated that its climb was 4,000 ft/min. Clearly you cannot expect the two to divide into each other but as a comparison the Beaufighter had a climb to 10,000 ft of 4.6 mins which is in the same ball park, but only had a max climb rate of 2,350 ft/min so the 4,000 ft/min claim I consider to be suspect.

It doesn't have any guns or ammunition which would impact the performance and probably doesn't have any armour, self sealing fuel tanks as I can find no mention of these items being fitted. So its performance as a fighter has a number of question marks against it and it has little strike capability. I also notice that the version is clearly labelled as being XF5-1 Land which makes me ask if any of the naval equipment had been removed.

Re the P39. It was advertised as being a 400mph fighter which it clearly wasn't but it also had a lot of things wrong with it which made it unsuitable for service and it was a similar story with the B17C. When the RAF first used the B17 in combat it was the USAAF advisers who were telling the RAF that it wasn't ready for combat which for an aircraft that was supposed to be in USAAF service in 1939/40 was a pretty damming indictment.

 

[tomo pauk]

Thanks for this. I notice that the XF5F has a climb to 10,000 ft of 4.2 mins but it has been stated that its climb was 4,000 ft/min. Clearly you cannot expect the two to divide into each other but as a comparison the Beaufighter had a climb to 10,000 ft of 4.6 mins which is in the same ball park, but only had a max climb rate of 2,350 ft/min so the 4,000 ft/min claim I consider to be suspect.

It's unfortunate that we don't have a real flight test, that served for basis of the table.

It doesn't have any guns or ammunition which would impact the performance and probably doesn't have any armour, self sealing fuel tanks as I can find no mention of these items being fitted. So its performance as a fighter has a number of question marks against it and it has little strike capability. I also notice that the version is clearly labelled as being XF5-1 Land which makes me ask if any of the naval equipment had been removed.

Remark 'land' means it does not have floats. The same remark is to be found on early SBD, F2A, XF4U-2 and F4F tables, late war tables do not* not use the remark.

Re the P39. It was advertised as being a 400mph fighter which it clearly wasn't but it also had a lot of things wrong with it which made it unsuitable for service and it was a similar story with the B17C. When the RAF first used the B17 in combat it was the USAAF advisers who were telling the RAF that it wasn't ready for combat which for an aircraft that was supposed to be in USAAF service in 1939/40 was a pretty damming indictment.

The early P-39s did have their share of problems, the problematic 37mm cannon being among the most prominent ones. As for being advertised to be capable for 400 mph - was it for the single, unarmed unarmored prototype with turbo, or the 'regular' ones, non-turbo (even the turbo was not capable for 400 mph), armored armed?
The early B-17s were not featuring self sealing tanks (introduced with -E?), like the rest of the world in 1939/40. The lessons of the air battles of 1940 will be implemented in later versions, it was too late for the -C (Fortress I). The excessive cold at 30000 ft played havoc with crew and guns, though we might expect same for other people's stuff happening the same, provided they were able to climb to that altitude. The rear quarter defense was problematic. Here is what Joe Baugher says:

Although the Army did not consider the B-17C as being combat ready (the E-version was already under procurement as the result of combat reports from Europe), the RAF was sufficiently desperate that these planes were immediately pressed into front-line service

Obvoiusly the B-17s produced in 19439/40 were not up the standards of air battles raging in the ETO of 1941, same goes for all other aircraft.

 

[Shortround6]

The XF5F-1 may have climbed at 4000fpm using the 1200hp take-off rating of the engine. That rating may only have been available for ONE minute. The chart may have been done using the "normal" 1000hp rating to start with but the engine needed to shift supercharger gears somewhere around 6000-7000ft.


As for the P-39, the most popular story is that the British were "told" the P-39 could do 390mph (or more?) and climb to 20,000ft in around 5.5 minutes ( the figures bandied around in the press and and many books since). The P-39 even with the turbo never came close to such figures.

Problems with the B-17s included guns freezing at high altitudes, windows frosting over, oxygen systems not working properly and the turbo systems (mostly the pressure regulator/s) not working properly (freezing the waste gate in one position) making the plane difficult if not dangerous to fly at high altitude even without enemy fighters showing up.

 

[tomo pauk]

Looking at the 'Shattered sword', at the pg. 547 is written that 'torpedoes could not be brought back aboard the ship once their plane was launched', source for this being being Michael Wenger. I assume this is only for the IJN?
Wonder whether anybody knows if the RN requirement was to bring back an un-expended torpedo?

 

[fastmongrel]

I imagine the Biplanes would have no trouble landing with a torpedo but it might have been fun in a monoplane with a higher landing speed

 

[oldcrowcv63]

I remember/read a story somewhere (Lundstrom?) about a USN Devastator(?) coming aboard the boat early in the war and its still attached torpedo accidentally released and skidded across flight deck fortunately doing no serious damage. I am not sure whether it went into the drink or not.

 

[oldcrowcv63]

With regard to the F5F, it seems like it had the potential to be an asset but, as has been pointed out, the timing was a bit late to make much of a difference and that difference might well have been on the negative side of the balance sheet. Considering the P&W R-1830-76/86 engines (or their superchargers) seem to have been a bottle neck to production in 1941, doubling the number used in one aircraft would seem to have come close to halving the number of USN carrier deployable fighters (F4F-3/4) in 42, with or without folding wings. In the event the Wright R-1820 engine was used, the numbers of Martlets available to the RN might have been adversely affected. As much as I think an F5F might have been a better performer than the F4F, it just wasn't available in time to help.

IMHO, the plane most needed by the USN from April 1942 to about the summer of 43, when numbers of F4U and F6F began to become available, was simply a folding-wing version of the F4F-3, aka FM-1 but with a reduced ammo supply to 300 rpg or less. The performance would have been intermediate between the F4F-3 and -4 and thus made a better interceptor than the -4. I don't know if USN aviators routinely kept the two outboard guns of the F4F-4 in reserve to double their firing time. I wish Rich Leonard were around to weigh in on this. His dad might have mentioned Navy pilot's general willingness to use the ploy. I'd expect, in a fight, one wouldn't hold back anything available to shoot.

 

[oldcrowcv63]

With regard to the F5F, it seems like it had the potential to be an asset but, as has been pointed out, the timing was a bit late to make much of a difference and that difference might well have been negative side of the balance sheet. Considering the P&W R-1830-76/86 engines (or their superchargers) seem to have been a bottle neck to production in 1941, doubling the number used in one aircraft would seem to have come close to halving the number of USN carrier deployable fighters (F4F-3/4) in 42, with or without folding wings. In the event the Wright R-1820 engine was used, the numbers of Martlets available to the RN might have been adversely affected. As much as I think an F5F might have been a better performer than the F4F, it just wasn't available in time to help.

IMHO, the plane most needed by the USN from April 1942 to about the summer of 43, when numbers of F4U and F6F began to become available, was simply a folding-wing version of the F4F-3, aka FM-1 but with a reduced ammo supply to 300 rpg or less. The performance would have been intermediate between the F4F-3 and -4 and thus made a better interceptor than the -4. I don't know if USN aviators kept the two outboard guns in reserve to double their firing time. I wish Rich Leonard were around to weigh in on this. His dad might have mentioned the pilot's general willingness to use the ploy. I'd expect, in a fight one wouldn't hold back anything available to shoot.

 

[davparlr]

I guess my thoughts on this is that many of the issues with handling twin engine aircraft, such as landing speed, landing weight, etc., could be handled by reinforcing the landing area of the deck and strengthening the arresting gear and protection net, as the Navy was going to have to address soon anyway. As for take offs, the Tokyo B-25 was prepared to launch with 2k bombs with long range. Doolittle stated he could, with about 10 mph wind, get off in 300 ft with light load, 600 ft with normal load. I would guess that the least wind across the deck would be 20-25 kts.

So, my plane hasn't changed much.
• It would be A-20 ish, max length 45'. Aircraft would fit on Lexington forward elevator and on Hornets elevators.
• Folding wing with vertical wing fold height of no more than 30'
• Max basic weight of 15,000 lbs.
• Wing area greater than 500 sqft.
• Normal mission radius of 400 miles with 2000 lb load, max radius 500 miles with 2000 lb. load
• Max speed at altitude >330 mph, max speed SL >300 mph
• Internal bomb bay capable of carrying bombs or torpedo.
• Cruising speed of 290 mph
• No turret.
• Two crew, pilot, bombardier/navigator.
• First hundred delivered by Feb., 1941

Carrier impact
• Increase strength of landing area
• Increase arresting gear strength
• Increase protection net strength

Carrier complement (note: fewer aircraft required)
• 40+ fighters
• 25 bomber/torpedo planes
• No obsolete TBD or SBDs
• Maybe some SBDs for scouting, maybe not.

Special requirements
• Torpedoes that work and that can be dropped at speed. If not use only low level bombing.
• Crews trained in low level bombing techniques
• Crews trained for higher performance aircraft for carrier ops.

Rationale. Bomber would depend on speed for protection like Mosquito. It would be faster than Japanese fighters, and also US Navy fighters, at altitude and at SL. Zeros would have very difficult time in attacking and could hardly maneuver when they did catch them and then only in a dive. Since bombers would be more effective, fewer would be needed so more fighters could be carried and could provide more escort and more carrier defense. Bombers could be stored on hanger deck.

I would think this is as close as you could get to a really useful twin engine aircraft on early carriers is based on speed for penetration effectiveness and survivability. This plane would have an equal or better speed advantage over the Japanese as the Mosquito had over the Germans.

Again, it would have taken a total mindset change and forward thinking of the Navy to have made such a plane.

 

[Shortround6]

It would also take some or all carriers out of action for a number of weeks if not a few months each (can be done in rotation so only one or two are out of service at once) in order to upgrade the elevators and landing systems ( and you have done nothing for the catapult/s).

You have two A-20 "prototypes"

The R-1830 powered version and the R-2600 powered version

The R-1830 versions may actually "fit" better being only 15' 10" high at the tail and weighing around 12,000lb empty depending on exact model. data form Joe Baughers web site.

For example French spec DB-7;
Two Pratt Whitney R-1830-SC3-G air-cooled radials, each rated at 1050 hp for takeoff and 900 hp at 12,000 feet. Performance: Maximum speed 280 mph at sea level, 305 mph at 9650 feet, 295 mph at 13,000 feet. Cruising speed 270 mph. Landing speed 81 mph. Initial climb rate 2440 feet per minute. An altitude of 12,000 feet could be attained in 8 minutes. Service ceiling 25,800 feet. 996 miles combat range. The DB-7 could fly 462 miles with a 2080 pound bombload. Weights: 11,400 pounds empty, 17,031 pounds maximum takeoff. Dimensions: Wingspan 61 feet 3 inches, length 46 feet 11 3/4 inches, height 15 feet 10 inches, wing area 464 square feet. Armament: Four fixed 7.5-mm machine guns fitted slightly behind and below the nose, two on each side. One 7.5-mm machine gun on dorsal flexible mount. One 7.5-mm machine gun in flexible tunnel position. Maximum internal bombload was 2080 pounds.

This is without self sealing tanks, no armor and a few things that are not quite right. Like while the contract called for a landing speed of 81mph actual flight testing resulted in the landing speed being 88mph. About an 18% increase in energy needing to be absorbed in the carrier arresting system. Normal fuel tankage was for 325 gallon and the French were complaining that the lateral stability was found wanting and the rudder didn't have enough authority when operating on a single engine or at low speeds.
Later planes shifted to the two speed R-1830 with 1100hp for take-off and 1000hp at 14,500ft. for a bit more performance but with the R-1830s you don't have the performance needed. Granted you are getting rid of one crew member and may have a smaller fuselage than the real DB-7 but I doubt the US would have accepted a plane with four .30 cal guns as a "fighter" so we are talking four .50 cal guns? Now four .30 cal guns went about 94.5 lbs and 500rpg added up to another 127-128lbs. Four .50 cal guns can go around 286lbs and 400rpg (less than a 4 guns Wildcat) is around 480lbs. An increase of over 540lbs. granted you can ditch the tunnel gun.

Going to the R-2600 gives you a couple of choices. You now have the power and speed but you have more weight, a higher tail fin (17' 7") that you may be able to trim/fold or extend in cord to reduce height? The Early R-2600 powered aircraft kept weight down by keeping the original fuel tanks (325 gallons max and 205 gallons "normal") which resulted in 1/2 the range of the R-1830 powered aircraft.

"Engines: Two Wright R-2600-A5B Double Cyclone fourteen-cylinder twin-row air-cooled radials equipped with two-speed superchargers, rated at 1600 hp for takeoff and 1400 hp at 10,000 feet. Performance: Maximum speed 344 mph at 12,500 feet. Cruising speed 275 mph. Initial climb rate 2420 feet per minute. Service ceiling 27,680 feet. 490 miles combat range. Dimensions: Wingspan 61 feet 3 inches, length 47 feet 0 inches, height 15 feet 10 inches, wing area 464 square feet. Weights: 13,674 pounds empty, 19,322 pounds gross. Armament: Four 7.5-mm machine guns paired in fairings on the side of the fuselage. One 7.5-mm machine gun in flexible dorsal position. One 7.5-mm machine gun in ventral tunnel position. One fixed aft-firing 7.5-mm machine gun in the rear of each engine nacelle. Maximum bomb load 1764 pounds."

Height may be wrong. Please note 2200lb empty weight increase. Getting a landing weight even close to 15-16,000lbs is going to be VERY difficult once you add 400lbs crew, guns, radio, oil and even minimal oil and fuel.

BTW, 2nd DB-7A with R-2600 was first flown Oct 10th 1940 but it took until late November to fix cooling problems with the engine.

By early 1941 you are into the A20-C model:

"Engines: Two Wright R-2600-23 Double Cyclone air-cooled radial engines, each rated at 1600 hp for takeoff and 1275 hp at 11,500 feet. Performance: Maximum speed 342 mph at 13,000 feet, 314 mph at sea level. Cruising speed 280 mph. Landing speed 100 mph. Service ceiling 25,320 feet. An altitude of 10,000 feet could be attained in 6.3 minutes. Range 745 miles with 1000 pounds of bombs. Maximum ferry range 2300 miles. Dimensions: Wingspan 61 feet 4 inches, length 47 feet 3 5/8 inches, height 17 feet 7 inches, wing area 464 square feet. Weights: 15,625 pounds empty, 21,000 pounds gross, 24,500 pounds maximum. Armament: Four 0.30-inch machine guns machine guns in the nose, two in lower nose and one in a teardrop-shaped blister mounted on each side of the nose. Two flexible 0.30-inch machine guns in flexible dorsal position. One flexible 0.30-inch machine gun in ventral tunnel position. "

Without some MAJOR weight reduction I am just not seeing this as a viable fighter plane. 1. It is not not stressed for fighter type maneuvers. 2, Both the climb rate and Ceiling to be polite, S**K.
A single R-2600 can suck down over 200 gallons an hour (3.4-3.5 gal min) at Military power or take-off power and around 150 gallons an hour (2.5 gal/min) max continuous. You are going to need 500-600 gallons to get any kind of range.