Grumman XF5F, what if?

[MIflyer]

Remember that at the time radar did not exist, as fr as anyone knew. Interceptors needed to be fats climbing because it was assumed the bombers would be at 20,000 ft plus, like the Y1B-17 could attain, and the first you would know of the bombers would be when they were nearby and nearly overhead.

 

[Shortround6]

Possibly. I can only go with what's printed in front to me. Mind you, I was drinking last night...

I am not doubting what you read, I may have doubts about what was written.

 

[R Leonard]

An interesting little read which covers USN fighter development as seen by BuAer. Late 1930's start around page 19. Scattered through are interesting tidbits on F4F, F5F, F4U, F5U, F14C, and such.

 

[Admiral Beez]

When it comes to figures on Wikipedia, salt in large quantity is essential.

Wikipedia can't even decide on the order of its performance stats and UOMs. Sometimes metric, sometimes imperial. It's no surprise that the actual details are unreliable.

 

[pinsog]

The speed figures both on Wikipedia and the book require a trainload of salt to digest. Especially the 382 mph at SL figure.
USN clocked the gun-less XF5F at 312 mph at SL, and 358 mph at 17300 ft. See here for data sheet.

As about the what if - yes, it has potential, with better engines, pilot and fuel protection, and some guns to shoot the enemy.

I believe it was BALLASTED for guns even if they weren't installed. Empty weight was 7990 pounds, over load weight was 10,892. Subtract 1700 pounds for 277 gallons of fuel, 200 pounds for a pilot and 150 pounds for oil and you have 852 pounds left unaccounted for. The radio was definitely installed.

 

[pinsog]

A couple of things that tickle me about the F5F:

US Navy "it's overweight so we are canceling it. We will be replacing it with the Corsair and Hellcat which both weigh more"

"the F5F showed how NOT to build a 2 engine carrier borne fighter. The F7F showed how to properly build a 2 engine carrier borne fighter (which couldn't actually land on a carrier)"

the brilliance of the upper level military of all nations astounds me

 

[pinsog]

The F5F is an interesting "what if" Let's assume you made the decision to put it into series production. It will be competing for engines with the F4F. How do you decide the relative proportions to build for either? At the time of Pearl Harbor, not all of the front line carriers had been converted from F2A to F4F, and at least one of the carriers was making due with the F4F3A with the single-stage supercharger. The only reason the 3a model was ever made was because Grumman could supply more airframes than Pratt & Whitney could supply 2-stage turbocharged engine. By December 1941, Grumman had shifted production to the F4F-4, but Yorktown and Lexington went to battle with F4F-3. the Dash-3 was faster and climbed better than the Dash-4, but you could fit fewer of them on carriers because they didn't have folding wings. There were enough dash-4 Wildcats to equip Yorktown, Hornet and Enterprise for the Battle of Midway in June 1942. Scrounging enough F4F-4s to supply the one US airfield on Guadalcanal was a constant problem August-November1942. Would the extra performance of the F5F outweighed the fact for every one you produced you gave up two F4Fs? I have my doubts.

The F4F-3 and F4F-4 Wildcat both used P&W 2 STAGE engines, the XF5F used Wright 1820 2 SPEED engines, same as the later model Dauntless used. So there wouldn't have been an engine constraint between those 2. Also, the wings folded on the XF5F and I think it was 22 feet with wings folded. I would liked to have seen an F5F with P&W 2 stage engines, it should have been a great performer

 

[MIflyer]

Well, the FM-2 used an R-1820 with only single stage 2 speed supercharging and it was a much better performer than the F4F, especially in terms of climb, but had a lower absolute ceiling. Two single stage supercharged 1350 HP R-1820's would have made the Skyrocket a real rocket, but that was rather late in the war.

 

[pinsog]

Well, the FM-2 used an R-1820 with only single stage 2 speed supercharging and it was a much better performer than the F4F, especially in terms of climb, but had a lower absolute ceiling. Two single stage supercharged 1350 HP R-1820's would have made the Skyrocket a real rocket, but that was rather late in the war.

That Wright 1820 in the FM2 would make 1480 WEP hp with water injection. Wouldn't that have been something….

 

[GrumpyOldCrewChief]

Wikipedia can be edited by anyone irritated enough to go to the effort...
... just sayin'...

 

[R Leonard]

Just for viewing pleasure, here is a shot that is part of a collection of, oh, 16 or 17, prints published by the Curtiss-Wright Propeller Division during WW2.

 

[SaparotRob]

It might not have been a great airplane but it sure looks cool. Especially if you read Blackhawk comics when you were a kid.

 

[Thumpalumpacus]

July 1938 the BuAer decides to submit a proposal for a twin engine fighter having the rate of climb of an interceptor after coming to believe that no single engine aircraft would be capable of such performance in 1937? Why do I get the feeling that they didn't bother to ask Curtiss? Perhaps Grumman was the favored supplier?
Beautiful job on the models.

What would it take to give the P-40 an interceptor's climb rate, and how would you marry that with the extra weight you're going to build into the aircraft to modify it for carrier ops? And did Curtiss have as much experience building carrier aircraft?

 

[GrauGeist]

And did Curtiss have as much experience building carrier aircraft?

Curtiss did build carrier aircraft like the F11C and BF2C and later, the SBC and SB2C, so they weren't complete strangers to Naval carrier requirements.

 

[R Leonard]

July 1938 the BuAer decides to submit a proposal for a twin engine fighter having the rate of climb of an interceptor after coming to believe that no single engine aircraft would be capable of such performance in 1937? Why do I get the feeling that they didn't bother to ask Curtiss? Perhaps Grumman was the favored supplier?
Beautiful job on the models.

From a history of the BuAer Fighter Design Branch history. Part 1 page 19 . . .

A few months before Lt. Comdr. Pride was transferred from the Class Desk A, a second letter went out to the various manufacturers requesting competitive designs and proposals for a two engine, single seat fighter. This was first inaugurated by Conf. ltr. Aer-E-16-EP-VF, dated 18 March 1937. Fourteen designs were submitted by six manufacturers: Lockheed, Curtiss, Grumman, Seversky, Vought, Brewster. However, since no twin engine fighter of less than 310 mph at 10,000 ft, offered sufficient advantages over the single engine types, then under construction, no design warranted an award. Although the proposal made by Lockheed did exceed this figure, it had disadvantages in cut, size, poor maneuverability and indifferent lateral vision.

Does not look like Curtiss was left out since they obviously submitted at least one design on that go around.

And, nor does it look like Curtiss was left out of the 1938 request; from the BuAer Fighter Design Branch history. Part 1 pages 30 & 31 . . .

Lt. Comdr. Farnsworth, on January 24, 1938, wrote a confidential memorandum to the Head of the Procurement Division requesting that letters be sent out requesting designs ad proposals from various airplane manufacturers because the Bureau was interested in procuring two experimental airplanes of the single seat fighter class, one having a single engine, and the other two engines. Type specification for the single engine type was to be Type Specification SD-112-13 and the General Specification SD-24-D. The two engine airplane, was to conform with Type Specification SD-112-14 and the General Specification SD-24-D. The proposals were to reach the Bureau not later than 11 April 1938, and the letter requesting bids was sent out 1 February 1938, by confidential letter Aer-PR-BA, VF.

On account of this active interest, on 1 February 1938, another request was made for designs and informal proposals for (1) a single engine fighter designed around the Allison mechanically supercharged engine, and (2) a twin engined fighter weighing less than 9000 pounds. The letter of 1 February 1938 set up the competition and bids were opened on 11 April 1938. At this time five airplane companies submitted ten designs, and in addition both Grumman and Curtiss submitted two designs and an alternate in the twin engine field. The following companies participated: Vought, Brewster, Grumman, Bell, and Curtiss.

One of Vought's proposals, called the Vought B proposal, introduced the gull wing and laid the foundation for the present Corsair fighter. This Vought design was considered an experimental project that would need exhaustive wind tunnel and engine tests because of its unconventional design and also because of the then existing status of the 2800 engine. However, in view of the fact that the Vought design could, if necessity arose, incorporate the R-2600 engine as an alternate, the plane appeared to show considerable promise. Thus, out of this competition came the XF4U-1, the Vought "B" proposal. As outlined in the proposal, the weight would be 6584 pounds. It is interesting to note that the F4U-1 of 1944 has a gross weight of 12,700 pounds, yet in spite of the doubling of the weight, there has been an increase of 80 mph speed over the original 356 mph originally calculated. The Pratt and Whitney R-2800 two stage engine was finally incorporated in the plane to give it its added performance.

The other design acted on by Class Desk A in conjunction with the other offices of the Bureau of Aeronautics was the proposal submitted by Grumman for a twin engine fighter which became the XF5F-1 (specification SD-112-14). This twin engined monoplane was powered by two Prat and Whitney R-1535-96 engines capable of developing a total of 1500 horsepower at 9500 ft. With the addition of two-stage equipment it was expected that the engines would develop this horsepower at 17500 ft.

 

[special ed]

Perhaps a twin engine P-40 with long nose Allisons similar to one modeller's twin P-40F here on site.

 

[MIflyer]

 

[pinsog]

View attachment 631666

Could you please take this pic down? I haven't had dinner yet…

is there any info on that thing? Did they try to fly it?

 

[MIflyer]

Note that it appears to be a P-40B fuselage.

And look at that superb streamlining on those nacelles! Looks like they made it out of discarded cardboard boxes.

I can only assume they were trying to sell it to the Blackhawks.

 

[pinsog]

Note that it appears to be a P-40B fuselage.

And look at that superb streamlining on those nacelles! Looks like they made it out of discarded cardboard boxes.

I can only assume they were trying to sell it to the Blackhawks.

I'd turn it upside down and put the cockpit on the bottom