Should Grumman have built a fighter for the US Army?

[R Leonard]

And one might want to remember that even after the F6F contract(s) were released, Grumman still had to build the facility for the production line, from the ground up. And part of the problem there was a scarcity, due to government controls, of building materials and allocation. F6F production was consequently slow to start . . . 1 in Sept 1942; 1 in Oct; 1 in Nov; 7 in Dec; 12 in Jan 1943; 35 in Feb; 81 in Mar; and, finally, triple figures in April 1943 with 131. F6F production peaked in Mar 1945 at 605, but fell off rapidly after that. Bear in mind that from Apr 1943 to Aug 1945 the monthly average was 416. Yearly totals were for 1942 - 10; 1943 - 2547; 1944 - 6140 and 1945 - 3578. (Dean Sinclair)

Apropos of nothing else, since the question was raised, my father on the way stateside from the VF-11 deployment to the Solomons in the spring and summer of 1943 where the squadron operated out of Guadalcanal's Fighter I field, equipped with F4F-4's and where he added two A6Ms to his total, had the opportunity to be checked out in a P-40E while at a stopover NAS Maui. He recalled that against Vals and Kates (and he had a few to his credit as well) the P-40 would be just fine, but that if he were faced with squaring off against a Zero he would much prefer his trusty F4F over the P-40.

Rich

 

[oldcrowcv63]

Rich, did your dad ever mention at what altitude were the IJN raids coming down the slot? My impression (largely from Lundstrom) is that the IJN TacAir (Kates and Vals) were coming in at altitudes similar to that used for their carrier strikes (I think ~15-20,000 ft) while the G4Ms might have been coming in a bit higher.
The raids on Java in early '42 appear to have been coming in at above 27,000 ft according to Bartsch making it really difficult for the P-40s to counter.

 

[VBF-13]

Another thing perhaps too obvious to mention is that Grumman had its hands full after Pearl and Midway designing and manufacturing for the needs of that theater, which centered on carrier-specific aircraft. By November of 1942 the flight and hangar decks of escort-carriers like the Chenango and Ranger were jammed-full of P-40s going off to land bases captured by the Army in North Africa to begin their operations there. The closest Grumman came to those was the handful of TBFs and F4Fs folded up on the crowded decks, there to provide aerial cover for the task forces while at sea. Oh, and the P-40 Warhawks were darn capable fighters; IMHO.

 

[oldcrowcv63]

Oh, and the P-40 Warhawks were darn capable fighters; IMHO.

VB,

No argument really. I just think the P-40E/F could and should have been even better, especially fulfilling the role of high altitude interceptor. I feel the same way about the F4F-4. JMO. Although in the latter case there seems to me to be somewhat less to lament.

 

[R Leonard]

Rich, did your dad ever mention at what altitude were the IJN raids coming down the slot?

Don't recall a specific mention of the Solomons. He did say that, overall, the combat he experienced was not above 10-12,000 feet and most much lower.

Rich

 

[Shortround6]

I just think the P-40E/F could and should have been even better, especially fulfilling the role of high altitude interceptor. I feel the same way about the F4F-4. JMO. Although in the latter case there seems to me to be somewhat less to lament.

It wasn't going to happen. The P-40 was too big and heavy for the available engine power. Try looking at the performance figures for the P-40L. 4 guns, reduced ammo, one fuel tank taken out and other modifications. It was still hitting about 8,000lbs ready to go. Compare to a Spitfire MK V. about 7,000lbs or under. A P-40 is going to need 14-15% more power than a Spitfire V even if everything else is equal.

 

[davparlr]

Apropos of nothing else, since the question was raised, my father on the way stateside from the VF-11 deployment to the Solomons in the spring and summer of 1943 where the squadron operated out of Guadalcanal's Fighter I field, equipped with F4F-4's and where he added two A6Ms to his total, had the opportunity to be checked out in a P-40E while at a stopover NAS Maui. He recalled that against Vals and Kates (and he had a few to his credit as well) the P-40 would be just fine, but that if he were faced with squaring off against a Zero he would much prefer his trusty F4F over the P-40.

Rich

I don't think any value can be made from this remark. Most pilots tend to prefer their own aircraft. In addition, no Navy pilot would choose a contemporary Army aircraft over the one he flew. If you were to take an experienced Army P-40 pilot and put him in an F4F-4, he would probably say the same thing and probably think the F4F was a slug. While I am certainly no particular fan of the P-40, the E was 40 mph faster than the F4F-4 and 20 mph faster than the Zero. When flown by competent pilots, this is a big advantage. Also, the P-40F, the contemporary to the F4F-4, was a different bird altogether with its Merlin engine. Certainly ceiling was an issue with the P-40 (except the F).

 

[VBF-13]

VB,

No argument really. I just think the P-40E/F could and should have been even better, especially fulfilling the role of high altitude interceptor. I feel the same way about the F4F-4. JMO. Although in the latter case there seems to me to be somewhat less to lament.

Oldcrow, I defer to you boys on details like that, 100%. Heck, if I can even contribute in some of these aircraft threads, it's only in a more general way. My Dad was a Naval aviator. Just call me somewhat of an informed enthusiast.

 

[R Leonard]

I don't think any value can be made from this remark. Most pilots tend to prefer their own aircraft. In addition, no Navy pilot would choose a contemporary Army aircraft over the one he flew. If you were to take an experienced Army P-40 pilot and put him in an F4F-4, he would probably say the same thing and probably think the F4F was a slug. While I am certainly no particular fan of the P-40, the E was 40 mph faster than the F4F-4 and 20 mph faster than the Zero. When flown by competent pilots, this is a big advantage. Also, the P-40F, the contemporary to the F4F-4, was a different bird altogether with its Merlin engine. Certainly ceiling was an issue with the P-40 (except the F).

I don't think any value can be attached to your remark.

I was simply answering a question. I hardly see anything in this above which qualifies you as a authority on the subject.

 

[FLYBOYJ]

Play nice folks....

 

[oldcrowcv63]

Don't recall a specific mention of the Solomons. He did say that, overall, the combat he experienced was not above 10-12,000 feet and most much lower.
Rich

Thanks Rich. I guess that appears to mitigate the impression that the P-40 high altitude shortcomings were all that consequential after the PI and Java experience. However, looking at the Lundstrom account for September 1942 I derived the following information:

8/7/42 (High altitude bombing attack on TF 62 ships)
21 x G4M Type 1 (BETTY) at 16,404'
12 x A6M-21 (ZEKE) at 19,684' close escort
5 x A6M-21 (ZEKE) at 27,880'
9 x Type 99 (VAL) at 9,840'
Defending F4F-4 CAP deployed at 12,000 ft due to Cloud OBSCX

8/8/42 (Low altitude torpedo attack on TF 62 ships)
23 x G4M Type 1 (BETTY) on deck
16 x A6M-21 (ZEKE) on deck close escort
Defending F4F-4 CAP deployed at 17,000 ft
Many raids on Cactus occurred between 8/8 and 9/12 but are not recorded in detail.

9/12/42 (High altitude bombing attack on Cactus)
25 x G4M Type 1 (BETTY) at 27,880' descended to 24,400'
15 x A6M-21 (ZEKE) at 27,880+' close escort
Defending F4F-4CAP deployed to ~29,000' before engaging retiring enemy

9/13/42 (High altitude AM Recon of Cactus)
2 Type 2 Reconnaissance Aircraft at 27,880'
9 x A6M-21 (ZEKE) at 27,880+' close escort
Defending F4F-4 CAP ascending to 30,000' when intercepted at 25,000'

9/13/42 (High altitude bombing attack on Cactus)
27 x G4M Type 1 (BETTY) at 24,600'
12 x A6M-21 (ZEKE) at 24,600+' close escort
Defending F4F-4 CAP deployed to ~27,600' before engaging approaching enemy

9/14/42 (Low altitude Float zero strafing of Cactus)
3 x A6M2-N Type 0 (Rufe) on deck
Defending F4F-4 CAP deployed to ~30,000' to engage approaching enemy

9/14/42 (Pre-AM Recon fighter sweep of Cactus)
7 x A6M-21 (ZEKE) at ~20,000+'
Defending F4F-4 CAP ascended to ~20,000' to engage

9/14/42 (Medium altitude AM Recon of Cactus)
1 Type 2 Reconnaissance Aircraft at 14,763'
Defending F4F-4 CAP deployed to ~30,000'

9/14/42 (Medium altitude float plane bombing attack on Cactus)
19 x F1M2 Type 0 (Pete) at 7,000'
2 x A6M2-N Type 2 (Rufe) at 7,000+' close escort
Defending F4F-4 CAP deployed to ~24,000' before engaging approaching enemy

9/27/42 (High altitude bombing attack on Cactus)
12 x A6M-21 (ZEKE) at 27,880+' (Air Control Force preceded attack by 15 min.)
17 x G4M Type 1 (BETTY) at 27,880' descended to 24,400'
17 x A6M-21 (ZEKE) at 27,880+' close escort
9 x A6M-21 (ZEKE) at 31,160+' (failed to engage F4F CAP)
Defending F4F-4 CAP deployed to ~29,000 ' to engage enemy

9/28/42 (High altitude bombing attack on Cactus)
26 x A6M-21 (ZEKE) at 27,880+' (Air Control Force preceded attack by 15 min. but launhed late)
25 x G4M Type 1 (BETTY) at 24,600'
15 x A6M-21 (ZEKE) at 27,880' close escort
Defending F4F-4 CAP deployed to ~28,000' to engage enemy

With the exception of the float plane and low altitude attacks this air campaign appears to resemble the IJN bombing raids on Java. Except in this case the IJN raids seem to have been very well countered by F4F-4s.

The above compares to the defense of Java by a squadron of P-40s, which appears to have been far less effectively countered. The USAAC P-40s, straining to achieve co-altitude with the bombers were rarely able to reach them let alone get the drop on their A6M escorts. Of course in addition to RADAR the Cactus based CAP had the coast watcher network. But Java had an early warning system as well and the 30+ minutes of warning it provided appears to have been sufficient for the F4F to launch and reach about 30,000'. Such comparisons are potentially flawed due to many factors but I am thinking the US pilot skill was comparable and the main difference appears to be the inability of the P-40 to reach sufficient altitude in time to make the intercept.

 

[oldcrowcv63]

It wasn't going to happen. The P-40 was too big and heavy for the available engine power. Try looking at the performance figures for the P-40L. 4 guns, reduced ammo, one fuel tank taken out and other modifications. It was still hitting about 8,000lbs ready to go. Compare to a Spitfire MK V. about 7,000lbs or under. A P-40 is going to need 14-15% more power than a Spitfire V even if everything else is equal.

SR, I appreciate your perspective on this, but I am really just thinking of improvments that might have been made for the sake of the P-40 in its interceptor role. If improvements can carve a minute or two off time to climb to max altitude and add a couple thousand feet in max ceiling than even in its underpowered incarnation, it would have been a more efficient fighter-interceptor early in the war. Even considering the USMC experience at Wake Island, I know of no cases where the F4F-3 or -4 carried a 500 pound bomb to sink a ship, yet it seems that the P-40 became an effective fighter-bomber early in the war doing that deed on a number of occasions.

Am I starting to sound like a one note samba yet?

 

[Shortround6]

The P-40 could perform a number of very useful roles and could fight at the lower altitudes very effectively, especially in the early part of the war. Without adding a turbo charger or some other major miracle it was never going to work at 25,000ft and above.

The P-40L used the Merlin engine with a two speed supercharger. It sacrificed hitting power, combat duration and range/radius in attempt at better performance. I am not sure what else you could do to it that didn't require major surgery that would make a significant difference like cutting several minutes to altitude or adding several thousand feet to it's altitude.

Getting good performance data is hard as the climb charts in the pilots manuals for US planes use military power for the first 5 minutes and then use Max continuous power for the rest of the climb so when you see a time to 20,000 ft of 11 or 12 minutes it MAY because the engine was throttle back after the first 5 minutes and that "climb rate" is not an indication of how well ( or not well_ the plane climbs at 20,000ft at full throttle. British climb to height figures use less than full throttle for the entire climb. It may tell how long it actually takes to get to that altitude but it doesn't tell you what the combat capability of the plane is.

Having said that try these manuals/ sites.

http://www.ww2aircraft.net/forum/attachments/other-mechanical-systems-tech/69920d1220649457-p-40-flight-manual-p-40f_foi.pdf

http://www.wwiiaircraftperformance.org/P-40/FL220-climb.jpg

Try using the lightest weight for the P-40F/L in the manual.

 

[oldcrowcv63]

Thanks SR, preciate the refs

 

[Major Minor]

I've often wondered why the army didn't at least approach, if not Grumman, then another Naval company and find out how they got such terrific range in their aircraft. I can understand them being hesitant to put the Merlin in the Mustang as it was a different country's product but was there that much animosity between services that they couldn't have worked together on better range?

 

[oldcrowcv63]

Here is the right thread: So I'll repost for continuity and posterity (because after all, what we post here will have great meaning to archaeologists from Zeta Reticuli in the human year 35,453 AD in trying to understand the great human air war of 1939-45 (human calendar).

SR, Been looking at the tables and charts for the P-40 F L and E (from tech section of the website) and the frustrating thing is that the gross weights quoted seem to be more alligned with generic combat loads than for the specific interceptor mission. For example, If I compare the GWs for the -L in the table and those in AHT, it seems OK. (8,486# (AHT vs 8,500#): so far so good assuming I add a drop 366# tank. (I don't know. but would be surprised to learn that F4F-4s flying interceptor missions out of Cactus in he Fall of 1942 used drop tanks, unless their early warning net gave them really advanced warning) On the other hand, the table purported to be applicable to the -F shows gross weights of 7,500, 8500, and 9,300# If I take the AHT clean GW of 8,678# and add a 366# tank it is well above the 8,500# and well below the 9,300# line. Are these meant to use as simple guides for interpolation? were performance nomographs ever published for any of these aircraft? In short, its difficult to estimate the performance of the P-40D-type A/C that might have provided a more effective interceptor early in WW2. Just how much climb and ceiling improvement can one expect for a 4-gun, allison powered ship with ~230 rpg?

 

[oldcrowcv63]

I've often wondered why the army didn't at least approach, if not Grumman, then another Naval company and find out how they got such terrific range in their aircraft. I can understand them being hesitant to put the Merlin in the Mustang as it was a different country's product but was there that much animosity between services that they couldn't have worked together on better range?

Major, the difference between army and USN aircraft ranges weren't all that great. The F4F and P-40 were similar generation and had similar ranges. The later P-47 and F6F and F4U apparently had somewhat similar ranges. The real difference in philisophy of fighter design appears to have been between the USA and the rest of the world. To some extent, A/C designs in the USA featured larger fuel capacity than those in Europe while Japan generally traded armor for range. These are very broad brush descriptions but I think they communicate the essence of the situation. if not, I am sure someone with a better grip (there are many such here whether on sanity or the facts) will interject a better summary.

 

[renrich]

Old Crow, many thanks for your research. You are a better man than I am. What your research indicates is that both IJN and US AC sometimes operated at pretty high altitudes in the PTO. On this Eurocentric forum it sometimes seems as if the combat in the PTO only took place pretty low and the AC could not manage to perform up high. My suspicion is that the combat both in the ETO and PTO happened at roughly similar altitudes. To me your research also supports the notion that the F4F may very well have been the most underrated fighter in WW2.

Every participant in WW2 knew how to build long range fighters. All that was needed was to trade off one or two characteristics in order to get long range. An extreme example would be the F4F7. It carried a massive amount of fuel in a wet wing. However, it was so heavy and underpowered it took a long time to get air borne and climb to altitude and it could hardly maneuver. Most fighters of the European powers did not need extreme range so the fighters were small, well armed, fast with big engines and pretty maneuverable and carried a relatively small amout of fuel. The only way to get a fast, well armed, rugged long range fighter was to build a big airplane with a very powerful engine that carried a lot of fuel. Those characteristics usually sacrifised some maneuverability. The Japanese philosophy was to get rid of weight and size by eliminating armor and self sealing tanks which allowed a smaller more fuel efficient engine which could go a long way on a small amount of fuel. No secret here just a choice of priorities.

 

[oldcrowcv63]

Ren, if you liked that, you may love this: According to Lundstrom, it looks like the IJN lost over 40 G4M BETTYs and about a dozen A6Ms (as well as over a dozen other types) during that run from 8/7 thru the end of September. That includes 4 IJN Ace pilots. The comparison with the Java experience is quite startling . I am guilty of often maligning the F4F-4 but it clearly got the job done, and may well be the most underrated fighter of WW2.

Ooops, I overcounted. Many (perhaps a dozen?) of those G4Ms were lost to AAA. Haven't done the total F4F losses during this period. Also, I am counting those aircraft that were wrecked beyond repair, even if they returned to base or ditched so this isn't meant to be a measure of the F4F effectiveness in air combat as it is a measure of its ability to attrite the enemy.

 

[Shortround6]

Here is the right thread: So I'll repost for continuity and posterity (because after all, what we post here will have great meaning to archaeologists from Zeta Reticuli in the human year 35,453 AD in trying to understand the great human air war of 1939-45 (human calendar).

SR, Been looking at the tables and charts for the P-40 F L and E (from tech section of the website) and the frustrating thing is that the gross weights ....... In short, its difficult to estimate the performance of the P-40D-type A/C that might have provided a more effective interceptor early in WW2. Just how much climb and ceiling improvement can one expect for a 4-gun, allison powered ship with ~230 rpg?

I would start with the lightest weight in the charts. 7500lbs for the "F"? and then the next higher and average them. The L went about 8000lbs clean (give or take).

The "D" or a light weight "E" isn't going to work at high altitude. Critical height for the engine was under 12,000ft compared to the 18500ft for the F&L. The E was going to be about 140-150hp down at 18500ft compared to an F. There is simply no way to strip out enough weight.

Look the charts in AHT the F is about 20-30mph faster than an E at 20,000ft and above. If the F or L won't work there is no hope for an Allison powered version.