What if: USAAC version of F4F

[gjs238]

Would a much lightened non-naval version of the Wildcat have improved performance enough to be competitive with the P-40?

It may have come close.
May have also made a sturdy close support ground attack aircraft.

 

[syscom3]

The P39 and P40 were better platforms for ground attack.

 

[davebender]

That's setting the performance bar rather low even in 1939. You should be trying for performance superior to the P-40 and F4F, as was finally achieved with the F6F.

 

[Shortround6]

That's setting the performance bar rather low even in 1939. You should be trying for performance superior to the P-40 and F4F, as was finally achieved with the F6F.

Then you need an F6F.

Look at the F4F-3.

How are you going to lighten it?

It has no folding wings, it has only 4 guns. over 2500lbs of it's empty weight is powerplant NOT including fuel tanks.

If you lighten the structure the "sturdyness" goes away.

 

[gjs238]

If you lighten the structure the "sturdyness" goes away.

For a non-naval aircraft it's overbuilt.
I'm not necessarily talking about stripping down an existing F4F, this is a what-if scenario pondering the potential of the basic design. As an example look at the P-51H.

 

[JoeB]

The F4F-3 was already relatively light, I agree, no major improvements to be made by adapting for ground use, especially if you want to streamline production and procurement. You have to make it a bit heavier in fact to incorporate armor and self-sealing tanks, just as happened in field modifications to F4F-3's in 1942, and also happened to P-40's at an earlier point. The main thing is leaving out the wing folding of -4.

But the F4F-3/4 proved themselves practically at least as capable as a air-air fighter in the Pacific as P-39 and P-40, more successful in fact in 1942 v Japanese Navy fighter units, but how much of that was USN/USMC training and leadership factors v USAAF will always be debated. The F4F had generally better altitude performance though, which was a clear problem for P-39/400's operating alongside F4F's at Guadalcanal, and also made P-39 and P-40 intercepts of high flying Japanese bomber formations more difficult in New Guinea and Australia.

For ground attack the air cooled engine of F4F was inherent advantage. Payload was less, though could probably have been expanded to 2*250# bomb as on FM series, if there was a need. But armament of fighter bombers IMO is sometimes overemphasized. In the Pacific, ground forces under attack by a/c were seldom even seen by the a/c. Most times they were semi-randomly bombing/strafing the jungle in the general area of enemy forces, wasting the overwhelming % of bombs and rounds of any caliber. Harrassing day time movement of the enemy along jungle trails or temporarily supressing fire from enemy fortifications against friendly ground forces were realistic goals for such strikes. The ability to drop a 500# bomb was significant in hitting ships, but P-40's and P-39's rarely did. I think a P-39 hit that damaged the Japanese light cruiser Kuma at Guadalcanal was the only bona fide bomb hit by P-39/40 on a significant sized ship. F4F-3's sank a DD of course, with a lucky 100# hit and strafing.

Joe

 

[Shortround6]

For a non-naval aircraft it's overbuilt.
I'm not necessarily talking about stripping down an existing F4F, this is a what-if scenario pondering the potential of the basic design. As an example look at the P-51H.

And the P-51 had a few issues with strength. Whither it was the smaller wheels or less structural strength or both the H model P-51 had more issues as a ground support aircraft than just the radiator.

THe Basic design of the F-4F vrs the P-40 includes the streamlining issue. the P-40 having a flat plate equivalent area of 5.71 sq ft vrs the F4F's 6.58 sq ft.

Not including fuel tanks the power plant weights were remarkably similar. THe extra weight of the P-40s radiator and coolant being offset by the F4Fs larger, more complicated supercharger and intercooler. This did give the F4F an advantage at higher altitudes but it is just so much dead weight for ground attack.

I mentioned the F4F-3 for a reason, the wing was about 300lbs lighter than the wing on a F4F-4. I don't know if it is because of the wing folding mechanisim, the provisions for the extra gun in each wing, the provisions for the 58 gallon drop tank under each wing or some combintaions of these reasons and/or others. Point being that at just under 900lbs for a 260sq ft wing you aren't going to get much lighter. Over 100lbs less than even an early P-40 wing.

The tail weighed about 145lbs and the fuselage (from the firewall back) around 520lbs. Landing gear weighed another 350lbs (several hundred pounds less than a P-40s landing gear).

I am left wondering where this big weight saving is going to come from?

 

[renrich]

If the question is whether an F4F could be made to be competitive with the P40, I believe that, on balance, it already was, particularly in the F4F3. The F4F3 with the added armor and the protected tanks was a decent early war fighter which, if well flown, could hold it's on with most other fighters of the same time period. The F6F and the F4U were superior in most respects to Japanese fighters in 1943 and gave their pilots a big advantage.

 

[MikeGazdik]

The tail weighed about 145lbs and the fuselage (from the firewall back) around 520lbs. Landing gear weighed another 350lbs (several hundred pounds less than a P-40s landing gear).

I am left wondering where this big weight saving is going to come from?

I am not questioning you, but holy crap, the F4F's landing gear was LESS than the P-40? By several hundred pounds?

I have looked close up at the F4F gear. That is some heavy duty stuff. I would never have thought a simple strut would be heavier than all of those folding arms on the Wildcat. Wow!

Is the F4F engine the same as the P-36? If not, then just reverse engineer the P-40 and put the F4F engine on the Curtiss. I think the Curtiss airframe is a far better land base design than the Grumman.

 

[Shortround6]

I am not questioning you, but holy crap, the F4F's landing gear was LESS than the P-40? By several hundred pounds?

I have looked close up at the F4F gear. That is some heavy duty stuff. I would never have thought a simple strut would be heavier than all of those folding arms on the Wildcat. Wow!

Is the F4F engine the same as the P-36? If not, then just reverse engineer the P-40 and put the F4F engine on the Curtiss. I think the Curtiss airframe is a far better land base design than the Grumman.

I certainly haven't weighed it. just going by the figures in "America's Hundred-Thousand".

The P-36 used a single stage supercharger. THe F4F use a two stage with intercooler. There are some photo's of the a company Hawk demonstraiter with the two stage supercharger and intercooler. The intercooler appears to be in a ventral tunnel located just behind/under the cockpit much like many radiators on liquid cooled aircraft. Better performance high up, more weight and drag low down.

 

[gjs238]

THe F4F use a two stage with intercooler. There are some photo's of the a company Hawk demonstraiter with the two stage supercharger and intercooler. The intercooler appears to be in a ventral tunnel located just behind/under the cockpit much like many radiators on liquid cooled aircraft. Better performance high up, more weight and drag low down.

Would this capability/feature have been of any use in the European theatre where so many operations took place at high altitude?

 

[Shortround6]

Would this capability/feature have been of any use in the European theatre where so many operations took place at high altitude?

As built the answer is probably no.
THe R-1830 as built offered 1000hp at 19,000ft military power. While better than the single stage Allisons this wasn't really much better than an early Merlin III (1030hp at 16,250ft). Later Merlins (and not the two stage ones) could do better. The German DB 601 engines in the early versions don't do quite as well but the timing of the 2 stage R-1830 is questionable. While an F4F doesn't fly with it until Jan 1939 (quite early) by Dec of 1940 only 22 production planes have been accepted. and one year later only 181 of the Two stage planes have been built. A number of F4F-3As and Martlet IIs have been built with a single stage, two speed engine that gives 1000hp at 14,500ft by dec of 1941.
I have no idea if they were having engine troubles with the 2 stage engine, or production problems or what.
The P&W 2 stage was the first of it's kind and might not have been ready for combat use until other, simpler systems had equeled it. The two stage supercharger would go on to be a very important development but the R-1830 version might not have faired well in Europe in 1942/43.

 

[drgondog]

And the P-51 had a few issues with strength. Whether it was the smaller wheels or less structural strength or both the H model P-51 had more issues as a ground support aircraft than just the radiator.

I would tend to question significant performance difference between D and H as a fighter bomber. It is true that the H was 11 1/2G ultimate at 8000 pounds and the P-51D was 12 G at 8000 pounds - but the P-51H was ~ 700 pounds lighter across the board from basic weight through a full load out - so the net difference for the two ships with 2x 1000 pound bombs, full ammo and full fuel was zero.

The smaller wheels may have made a difference on a rough field. On the other hand I like the straight leading edge on the H as an opportunity to make the wing stronger with less weight than the D wing with the strake to accomodate the larger wheel..

Remember the P-51H was redesigned in every way except for the lines and even those were altered slightly with the 13" extension for the fuselage to rid itself of the aft cg issue with the fuse tank... so structurally it Was designed with the ultimate loads in mind from day one.

The P-51D was a weight increase (additional) to the same airframe as the B which in turn was largely the same as the A but increased in weight (and drop the wing 7" to accomodate the Merlin). If anything the D was less sound than the H.

The F4, if fuselage lines were essentially to be retained as P-51A to B to P-51D to H, would have little opportunity for the same boost in performance by redesigning internally (as you pointed out) simply because one could not continously increase engine performance in the same out countour lines. The Mustang doubled Hp from XP-51 through P-51H

I agree all your points re: P-40 vs F4F

 

[Shortround6]

I could have been mis-informed on the P-51H. Maybe there just weren't enough of them to keep when when there were so many "D"s and spare parts on hand but I was under the impression that the "H" went out of service before the "D"s. Perhaps the less rugged "story" is just a red herring

 

[Shortround6]

For a picture of the hawk 75 with a 2 stage supercharger see:

http://www.warbirdsresourcegroup.org/URG/images/p36-1.jpg

Notice lump behind engine on the bottom and what may be the intercooler in the pod/tunnel behind the left landing gear.

 

[davebender]

The U.S. Army hated the USN during the WWII era. This continued at least until October 1944. Gen. MacArthur's 7th Fleet apparently had no liason at all with the USN 3rd Fleet which almost lead to disaster at Samar on 25 Oct 1944. Given this almost complete non-cooperation it's difficult to imagine a joint USA - USN aircraft project.

However if someone manages the miracle of making the USN and U.S. Army Air Corps cooperate I would not waste it by building a land based F4F. Make a land based version of the F4U Corsair. With a better supercharger the Army F4U could enter production during early 1943 ILO the P-47. You could also phase out the problem plagued P-38.

The P-39 and P-40 can remain in production forever as our lend-lease gift to the Soviet Union.

 

[tomo pauk]

Good call about the USAAC F4U.

 

[drgondog]

I could have been mis-informed on the P-51H. Maybe there just weren't enough of them to keep when when there were so many "D"s and spare parts on hand but I was under the impression that the "H" went out of service before the "D"s. Perhaps the less rugged "story" is just a red herring

IIRC - there were about 13 common fabricated parts in common between the D and H. I am not sure what the cycle of USAF to Guard to retirement was for the H but I will look it up.

I never flew the H but the jocks I have talked to say it simply was a better aircraft and fighter than the D although of course none ever saw combat. The D saw combat in Korea simply because a fair amount were on hand in Japan and also with the ROK air force, so the logistics were in place and also largely deployed in Guard units that were rotating to Japan.

To emphasize a point - the H was designed at 7 3/4 G limit load and 11 1/2 Ultimate at 8,000 pounds so on paper it was more 'fragile' than the D at the same weight - but the reality is that they were equal at same payload because the H was significantly lighter before mission loads were applied.

 

[Shortround6]

The U.S. Army hated the USN during the WWII era. This continued at least until October 1944. Gen. MacArthur's 7th Fleet apparently had no liason at all with the USN 3rd Fleet which almost lead to disaster at Samar on 25 Oct 1944.

This may be more an indication that Gen. MacArthur couldn't get along with anybody rather than evidence that the Army and Navy couldn't get along.

Given this almost complete non-cooperation it's difficult to imagine a joint USA - USN aircraft project.

while a "joint" project might not have worked very well there was a "naval" version of the P-39. the XF5F-1 Skyrocket had an Army counterpart. The Army did fly Dauntless dive bombers and Curtiss Helldivers (and turned down more because they didn't suit army missions) while the Navy did buy and fly B-25s and had their own version/s of the B-24. Both forces also flew Lockheed Ventura's although the Navy made much more use of them. Both forces used the same cargo and transport planes. Doesn't seem like there was a huge aversion to using the other guys airplane as long as it did the job.

However if someone manages the miracle of making the USN and U.S. Army Air Corps cooperate I would not waste it by building a land based F4F. Make a land based version of the F4U Corsair. With a better supercharger the Army F4U could enter production during early 1943 ILO the P-47. You could also phase out the problem plagued P-38.

Just what is this "better supercharger" supposed to be?
A few details please.

The production line/s for the P-47 are already up and starting to run. with 532 P-47s built in 1942 compared to 178 F4Us. 1583 P-47s are on order in Oct of 1941 and another 1400 are ordered in Jan 1942, with over a thousand of them from a new factory in Evansville, Indiana and the remainder from Curtiss.

Just how many hundreds if not thousands of fighters are you willing to "loose" at this point in the war to change over the production lines?

as far as the " problem plagued P-38" goes, this is the same "problem plagued" aircraft that shot down Yamamoto right? this is the same "problem plagued" aircraft that started flying itself to Europe in the summer of 1942?
And of course coming up with a few thousand extra R-2800s for these fighters that are going to replace JUST the 1943 P-38 production isn't going to be any problem either?

 

[Shortround6]

IIRC - there were about 13 common fabricated parts in common between the D and H. I am not sure what the cycle of USAF to Guard to retirement was for the H but I will look it up.

I never flew the H but the jocks I have talked to say it simply was a better aircraft and fighter than the D although of course none ever saw combat. The D saw combat in Korea simply because a fair amount were on hand in Japan and also with the ROK air force, so the logistics were in place and also largely deployed in Guard units that were rotating to Japan.

To emphasize a point - the H was designed at 7 3/4 G limit load and 11 1/2 Ultimate at 8,000 pounds so on paper it was more 'fragile' than the D at the same weight - but the reality is that they were equal at same payload because the H was significantly lighter before mission loads were applied.

thank you for the information. I hadn't realized the two aircraft were quite that different.

I certainly wouldn't worry about .25-.5 worth of difference unless somebody could actually document cases of structural failure that were caused by design and not fabrication or faulty components, and I don't think anyone can. If somebody could at the time the fleet would have been grounded I would think, we weren't at war any more after all.

Chalk another one up to" what we know that ain't so"