P82 vs Do335

[SunTracker]

PERFORMANCE
Maximum speed: 482 mph
Cruising speed: 280 mph
Range: 2,200 miles
Service Ceiling: 39,900 ft



Performance: Max speed 474 mph (763 km/h) at 21, 325 ft (6,500 m); Max cruising speed 426 mph (685 km/h) at 23,360 ft (7,100 m); Economical cruising speed 281 mph (552 km/h) at 19,685 ft (6000 m); Range on internal fuel at max continuous power 867 miles (1400 km), at economical cruise power 1,280 miles (2050 km); Time to 3,280 ft (1000 m) 55 sec, to 26,245 ft (8000 m) 14.5 min; Service ceiling 37,400 ft (11,400 m).

How would these aircraft have matched up if they had met in combat?

[Jester]

Would imagine the DO 335 would be the better aircraft.

While a bit slower -  it most likely weighs less thus making it more manuverable thus making it a better dogfighter.

P-82 "Twin Mustang" was a long range fighter/bomber interceptor more along the line of the ME-110.

Interesting thought though.
!

[HoHun]

Hi Sun Tracker,

>How would these aircraft have matched up if they had met in combat?

Interesting question :-)

I'd say it mostly depended on altitude. The Do 335's DB603A gave good power at low and medium altitude, but was a mediocre performer up high. The P-82B's V-1650-22/23 on the other hand probably had the Merlin-typical good high-altitude performance (I don't have a power graph for that specific engine type).

With regard to combat characteristics, the Do 335 with its centreline layout and its hydraulically boosted ailerons certainly had an advantage in roll rate. The P-82 on the other hand offered better rearward visibility and had the advantage of having an additional pair of eyes on board.

(By the time the first P-82B left the production line, Dornier would have switched production to the Do 335B with the more powerful DB603E-1 or DB603LA engine, and especially with the latter, the performance advantage probably would have resided with the Do 335.)

Regards,

Henning (HoHun)

[hawker238]

How difficult was it to aim the 82's guns?

[Widewing]

Originally posted by Jester
Would imagine the DO 335 would be the better aircraft.

While a bit slower -  it most likely weighs less thus making it more manuverable thus making it a better dogfighter.

P-82 "Twin Mustang" was a long range fighter/bomber interceptor more along the line of the ME-110.

Interesting thought though.
!

Actually, the Do 335 weighs nearly a ton more than the P-82, even if the Twin Mustang has full internal tanks (it would not need external tanks to operate anywhere over Germany). However, by the time they reached Germany, about 30% of the fuel would have been burned. Either way, the P-82 has a lower wing loading, becoming substantially more lopsided as fuel burns off. P-82 pilots who converted from the P-51D described the P-82 as being considerably more agile than the P-51. North American Aviation test pilot George Welch (who flew the P-38 against the Japanese) found the Twin Mustang to be, and quote, "considerably superior to the P-51D in every aspect of air combat."  

What we have here is an interceptor designed to kill high altitude bombers vs. a high altitude fighter designed to kill interceptors.

I lean towards the Do 335 being far less effective than the Me 262, and far more vunerable to boot.

My regards,

Widewing

[HoHun]

Hi Widewing,

>Actually, the Do 335 weighs nearly a ton more than the P-82, even if the Twin Mustang has full internal tanks (it would not need external tanks to operate anywhere over Germany).

Do 335A: 10200 kg (1150 kg fuel)
P-82G: 9080 kg (1630 kg fuel) => 7930 kg (1150 kg fuel)

>Either way, the P-82 has a lower wing loading

Do 335A: 265 kg/m^2, 0.36 kg/HP
P-82G (1150 kg fuel): 204 kg/m^2, 0.49 kg/HP

(Power loading based on maximum power.)

>North American Aviation test pilot George Welch (who flew the P-38 against the Japanese) found the Twin Mustang to be, and quote, "considerably superior to the P-51D in every aspect of air combat."

Well, there should be a difference between the 1945 Merlin-powered P-82B and the late-1946 Allison-powered versions like the F-82G I listed above.

>What we have here is an interceptor designed to kill high altitude bombers vs. a high altitude fighter designed to kill interceptors.

The Do 335 actually didn't follow any special fighter concept but was rather a high-speed bomber adapted for the fighter role (similar to the Mosquito).

With regard to the P-82B comparison, I'd say that the Do 335B held the speed, firepower and roll rate advantages, while the P-82B held the turn rate, visibility and range advantages.

(The climb rate comparison depends on the exact DB603 variant used and of course on the power of the V-1650-22/23, so I can't comment on that yet.)

>I lean towards the Do 335 being far less effective than the Me 262, and far more vunerable to boot.

Well, I'm afraid I don't know what you mean by "far more vulnerable".

With regard to the Me 262 comparison, the Do 335's main strengths was the long endurance and rough field capability (due to propeller power) so that they wouldn't have had to scramble from and land back on bases that were under constant attack.

Performance-wise, the Me 262 of course was superior to the Do 335, just as it was to any other piston fighter of the era.

Regards,

Henning (HoHun)

[Tony Williams]

The armament comparison is interesting. Most of the Do 335s had one MK 103 engine cannon and a pair of synchronised MG 151 (there is some confusion about whether the 15mm version was used in some installations), although the B-2 added another pair of MK 103's in the wings.

The MK 103 was a very powerful, long-range gun and the MG 151/15 was also superior to the .50 in power, but their combined rates of fire were much lower than the US armament. It would probably have come down to luck; the US plane would have scored more hits but the Do only had to connect once with that 30mm cannon.

Tony Williams: Military gun and ammunition website and Discussion forum

[Westy]

I still think the P-47M would have eaten the DO-335 alive

[M.C.202]

The sources I have give the V-1650-21/23/25 as being "similar to V-1650-11.
At 4,000,  low blower, water injection on... 2,270BHP @3,000rpm @90"hg
At 19,400, high blower water injection on... 1,860 BHP @3,000rpm @90"hg
400 rounds per gun, and an eight-gun pod could be fitted under the center section of the wing...
Base weight was 15,615, max was 24,864
The P-51H was a single engine P-82, not the reverse.

[GRUNHERZ]

Originally posted by M.C.202

The P-51H was a single engine P-82, not the reverse.

Though not exactly accurate, it's a pretty intresting way of putting it.

[HoHun]

Hi Tony,

>The MK 103 was a very powerful, long-range gun and the MG 151/15 was also superior to the .50 in power, but their combined rates of fire were much lower than the US armament. It would probably have come down to luck; the US plane would have scored more hits but the Do only had to connect once with that 30mm cannon.

By your own calculations, the two MG151/20 cannon alone had the same firepower as the Twin Mustang's six Brownings and the MK103 added almost twice the firepower again.

There is absolutely no contest - the Do 335's firepower was far superior to the P-82's.

If a battery can deliver the number of projectiles required for a certain probability of kill in a shorter period of time than another battery, it's superior. The absolute number of rounds is quite irrelevant. With about three times the firepower, the Do 335's battery is superior to the P-82's anywhere in effective range.

Luck has nothing to do with it.

Regards,

Henning (HoHun)

[Widewing]

Originally posted by HoHun
Well, there should be a difference between the 1945 Merlin-powered P-82B and the late-1946 Allison-powered versions like the F-82G I listed above.

Differences are significant in that the F-82G was a night fighter, fitted with a large under-wing radar pod and its associated hardware.

Had the war in Europe continued on into 1946, the P-82B would have remained the primary varient, supplemented by the 487 mph P-51H. Indeed, had it appeared that the war would drag on that long, the Republic XP-72 would not have been cancelled. This monster, armed with with the proposed four 37mm guns (Republic's Chief Engineer has stated that the probable  production armament would have been six Hispanos), would have been capable of level speeds right at 500 mph (both prototypes reached 490 mph on 450 less HP than the spec engine).

I view the Do 335 as being badly outclassed as a fighter, and being considrably slower than the Me 262, it would have been hard pressed to escape the newer generation of Allied piston-engine fighters using speed alone.

My regards,

Widewing

[HoHun]

Hi Widewing,

>I view the Do 335 as being badly outclassed as a fighter, and being considrably slower than the Me 262, it would have been hard pressed to escape the newer generation of Allied piston-engine fighters using speed alone.

Well, that depends on the numerical ratio between Allied fighters and the Do 335s. Facing equal numbers, the Do 335 certainly would have been highly competetive.

By the end of 1945, the Do 335 would have been powered by the DB603LA with 1800 HP at 9 km altitude. By the time the P-72 would have been ready, the Do 335 probably would have been powered by the Jumo 222E/F.

>both prototypes reached 490 mph on 450 less HP than the spec engine).

The Do 335 prototype reached 482 mph in 1944. That was with the DB603A engines which had 700 less HP than the DB603LAs, and a full throttle height of 6 km compared to the DB603LA's 9 km.

>escape the newer generation of Allied piston-engine fighters using speed alone.

Hm. Speed is an essential offensive quality.

Regards,

Henning (HoHun)

[Tony Williams]

Originally posted by HoHun
There is absolutely no contest - the Do 335's firepower was far superior to the P-82's.

If a battery can deliver the number of projectiles required for a certain probability of kill in a shorter period of time than another battery, it's superior. The absolute number of rounds is quite irrelevant. With about three times the firepower, the Do 335's battery is superior to the P-82's anywhere in effective range.

Luck has nothing to do with it.

I would entirely agree with you in the case of attacking large bombers which could soak up a lot of fire before going down. However, the .50 was generally adequate against fighters so the Do 335 might have been disabled by a few .50 hits, depending on where they landed. Sure the Do's armament was far more destructive, but against fighters the six .50s were probably destructive enough.

So if you could run a one-on-one combat between these armament fits a hundred times over, I would expect the Do to win most of them, but lose some on those occasions when the P-82 could land some .50 bullets in the right place - which is really down to luck.

Tony Williams: Military gun and ammunition website and Discussion forum

[M.C.202]

GRUNHERZ said:

Though not exactly accurate, it's a pretty intresting way of putting it.

By this I mean that the research and design put into the P-82 was the basis for much of the H model re-design.
It was the "clean sheet" that allowed for better (faster and cheaper) unit production, and incorporation of the latest drag studies.

I see the P-82 vs Do 335 question revolving on who sees who first. If Co-E and Co-alt, the better wing loading and the better range of vision (not counting the extra set of Mk1 eyeballs) of the P-82 would give it the edge.

As to the P-72, it was first flown in Feb of '44. The 490 mph "on the books" speed and the "500mph" run was with the four blade (rather than the planned six blade counter rotating one) prop was in '44.

I look at design and production dates to see what matches to what, rather than the "saw combat use" thing. This is a game using pre-Sept '45 aircraft out of their historic context, not a WWII re-creation. If it was re-creation only one of twenty pilots would be in "late" aircraft in combat, worse for the Axis birds.