Heavy fighter: you are in charge

[Shortround6]

2700rpm

You are of course, correct. My apologies, I was away from my books at the time at was looking at Wiki. Some engines did use a higher take off rpm that was not used for other flight conditions and I thought the DB 603 might be one of them.

 

[Shortround6]

Hello Wuzak
IMHO P-61E only shows that Riacrato's opinion, that why bother to design a heavy twin fighter, why not design a twin or Zwilling a la P-/F-82 Twin Mustang, has a good point.

Juha

The problem with using a "Zwilling" is that it doesn't give much more range than the parent single engine fighter. Fine if you are starting with a Mustang, not so good if you are starting with a 109 or Spitfire. Only large space for more fuel is taking out the second cockpit which rather limits nightfighting ability or fitting long range radios? Some Zwillings would be hard press to be fitted as night fighters in any case. Want to try to cram the needed radar equipment into a 109 cockpit even if you take out the normal instrument panel? One of the things they didn't like about the He 219 was not enough room for the radar operator.

 

[tomo pauk]

As for Zwiling's fuel tankage, it all depends what the designers/costumers want to accomplish.
The twinned Spitfire, for example, can house it's armament ammo in central wing, leaving outer wings free for extra fuel. For 109, the central battery can be retained, leaving room for fuel tanks both inner outer wing panels. Both planes were featuring radio sets in rear hull - since only one radio set is needed, the rear part of another hull can house radar electronics.
British were able to install radar in their Defiants as early as 1940 (while still retaining the turret), so I see no problems for a twinned Spit to carry a radar set.

 

[spicmart]

An italian design with similar dimensions as the Whirlwind. Pretty neat looking plane like most italian designs. Needs better engines of course.

 

[wuzak]

Hello Wuzak
IMHO P-61E only shows that Riacrato's opinion, that why bother to design a heavy twin fighter, why not design a twin or Zwilling a la P-/F-82 Twin Mustang, has a good point.

Juha

But zwillings didn't work. The Germans tried for a Bf109Z - but that got nowhere.

The twin Mustang worked, but it didn't appear until 1946 and was very much a new aircraft and not a zwilling - despite appearances.

 

[pinsog]

I haven't seen anything mentioned that would come close to matching an XP-72 Super Thunderbolt. Wish they had built a few and deployed them. What a machine.

 

[tomo pauk]

But zwillings didn't work. The Germans tried for a Bf109Z - but that got nowhere.

The twin Mustang worked, but it didn't appear until 1946 and was very much a new aircraft and not a zwilling - despite appearances.

Claiming that twinned planes did not worked, because Bf-109Z was damaged by allied bomb(s) and never repaired, is hardly some conclusion.
Sure enough that a twinned plane is not something to be made quick-and-dirty; having many components is mass production can help to drive the price down, while expediting the delivery of the plane.

 

[Shortround6]

Claiming that twinned planes did not worked, because Bf-109Z was damaged by allied bomb(s) and never repaired, is hardly some conclusion.
Sure enough that a twinned plane is not something to be made quick-and-dirty; having many components is mass production can help to drive the price down, while expediting the delivery of the plane.

The Bf-109Z may have worked quite well in some roles, not so good in others ( one account says second cockpit area used for fuel tank/s). the more modifications that are made the fewer common parts are used and the rational for the idea starts to loose it's attractiveness.

While the P-82 looked like a twin mustang the Fuselages were almost entirely new. You had the new wing center section, new tailplane , new landing gear ( by the time you get to the P-82E you are dealing with 14,914 pounds empty and 24,864 pounds maximum) . One source says had 576 US gallons internal fuel?

The F-82 was not a small airplane.

Something to consider is that the original heavy fighters were built with certain goals in mind and were not small twins with small engines comparable in size to large single engine fighters like the Whirlwind and Ro-57 (which had a smaller wing than a Typhoon)

 

[muscogeemike]

Anyone remember the P-75? If further developed it might have been worthwhile.

 

[wuzak]

Anyone remember the P-75? If further developed it might have been worthwhile.

Doubtful, but what about a XP-67 with turbocharged (or turbocompound) Allisons or two stage Merlins?

405mph on engines giving just over 1000hp (and much the same as the XP-49, which was largely based on the P-38).

Surely looking at over 450mph for a pair of Merlin 70 series?

Also, ditch the 6 x 37mm armament, and replace with 6 x 20mm Hispanos. Or 4 x 20mm Hispanos and 2 x 37mm (to keep the AAF happy a sit wa sone of their favourite weapons). Just don't bother loading ammo for the 37s....

 

[MikeGazdik]

You mean like the P-61E or F-15 Reporter?

http://upload.wikimedia.org/wikipedia/commons/9/98/P-61_aka_F-15A_bw.jpg

http://aerofiles.com/north-p61e.jpg

The P-61E was to be a heavy day fighter.

Wow! I had never ever known of the P-61E. See, I was on to something. That plane would have been perfect! Any test data on it's performance? This thread is closed, P-61E would be the supreme heavy fighter.

 

[wuzak]

Wow! I had never ever known of the P-61E. See, I was on to something. That plane would have been perfect! Any test data on it's performance? This thread is closed, P-61E would be the supreme heavy fighter.

Very much the same as the P-61A/B, I believe - meaning top speed of around 380mph.

I would also argue that it would be a better arrangement for teh night fighter version - ditch the nose guns for the radar - 4 x 20mm should be plenty for a nightfighter. Two crew instead of three, no pesky 4 gun turret to worry about.

 

[Juha]

But zwillings didn't work. The Germans tried for a Bf109Z - but that got nowhere.

There were some outside forces working against 109Z, Germans seemed to have had some intrest on Zwillings late in the WWII, IIRC there were plans for Twin Do 335, was that Do 445 for ex.

The twin Mustang worked, but it didn't appear until 1946 and was very much a new aircraft and not a zwilling - despite appearances.

Yes i know, IIRC the fuselages were lenghtened for more room for extra fuel and extra electronics for very long range work, IMHO a Twin Spitfire would also needed longer fuselages for same reasons or at least for some changes so that rear fuselage fuel tanks would have had less effect on handling than in late Mk IXs.

Juha

 

[tomo pauk]

Something that should've, hopefully, increased a number of P-38s - the non-turboed versions? Not the Merlin version (though that one seem like a winner), but a regular V-1710?
Such planes, historically, were featuring 2 x 1040 HP (the C-series) engines, considered by the RAF in 1940, and low-level F-series ( used by USAAF in the USA only, supercharger ratio 6.44:1,relic from the turboed engine version, unlike the 'usual' 8.80:1 as found on P-39/40/51s of 1942). The P-38F, with 1150 HP, was capable of 370 mph at 15000 ft. Since 'my' P-38 would've used the exhaust thrust, then another 10 mph should be added? The plane is lighter, the drag is lower, the WER rating is about 1500 HP at 4500 ft (no ram), easier to maintain, cheaper. More than enough for Asia/Pacific prior 1944?
By late 1942, the engine with 9.60:1 is in production, so the max speed should be attained at 17-18000 ft. The WER is some 1400 HP @ 9500 ft (no ram). Again, the P-38F was capable of 380 mph @ 18000 ft, adding some 10 mph due to exhaust thrust makes 390.
With 1325 HP, the P-38F was tested 365 mph at 8000 ft, 375 at 12000 ft, so the non-turbo should have no problems to top this.

But, then, again, P-51(A) can do even better

 

[Shortround6]

I am not sure that P-38 production was held up by a lack of turbos, at least not often or not long ( I would not be surprised if there were temporary hiccups in supply). At times in 1941 (?) the Army was rationing Allison engines to airframe makers but that had nothing to do with the turbos. Compared to the total weight of the plane the turbos just weren't that heavy. Until you get to the "J" there isn't going to much of change in drag in drag due to leaving out the "inter coolers" although the extra fuel tankage might come in handy. Jet thrust works better the higher you go, less back pressure means higher exhaust velocity. A Merlin XX got 86.5 Hp at 325mph at 15,000 from jet exhaust with a charge flow of 140lbs per minute. At 30,000ft it got 89hp (in between was more with a high of 127hp) at 317mph with a charge flow of just 107lbs minute. While jet thrust helps speed it doesn't do any where near as much for climb.

The 109 Zwilling had just under 250sq ft of wing which gives it about 6-7% more than a P-51 or 61% of the wing of a P-82. It just isn't big enough to hold everything that a P-82 could, something has to give. 2nd crew member and radar or fuel?

 

[tomo pauk]

My idea for more 'P-38s' is pointed towards man-hours per a plane produced, more than towards any perceived lack of turbo set-ups.
The decreased maintenance should be also adding to the serviceable vs. available planes ratio (ie. more planes in combat for same number of on-hand ones). The two turbos deleted should make plane weight 600+ lbs less (same as 100 gals of fuel), so the climbing abilities would remain competitive. More so the short climbs during combat in lower altitudes with introduction of WER, some time in second half of 1942. The drag should go down since the airframe where once the turbine was would be far better streamlined (5 mph extra?).

The 109s were carrying some 100+ gals of fuel. With just extra 100 gals in wings (for 300 gals total, internal), the 109Z has useful range. So I'd give 270 gals of fuel

 

[Arossihman]

F7F-Tigercat

 

[davebender]

Nothing wrong with the F7F. Powered by R2800 engines so it theoretically could have been designed early and entered production during summer 1942 along with the F4U. A 1943 model F7F would have less engine power then the post-war F7F but it would still be faster then anything Japan had.

 

[tomo pauk]

Tigercat is an awesome looking plane, with capabilities to go with that.

 

[Arossihman]

Tigercat is an awesome looking plane, with capabilities to go with that.

Kind of my thoughts as well although i've heard it did'nt have the best carrier traits for landing on flight decks it was still a very good land based aircraft.