Assessing the Dornier 335’s capabilities as a fighter

[Soren]

Assessing the Dornier 335's capabilities as a fighter.

Fighter, A-1 A-5.

Specifications:

Loaded Weight: 9590 kg

Wing area: 38.5 m^2

Wing span: 13.8 m

Wing aspect ratio: 4.94

Wing Clmax: ~ 1.65 (?)

Length: 13.87 m

Powerplants: 2x DB-603E engines rated at 1,800 PS take off power, and 2,400 PS at emergency power using methanol water injection.

Top speed: 763 km/h @ 6,400m (565 km/h on 1 engine)

Climb rate: 23.3 m/s (4,600 ft/min)

Service Ceiling: 11,800 m

Armament: 3x 30mm Mk103 automatic cannons + 2x 20mm MG151/20 automatic cannons

Optional armament: 2x or 4x R4M rocket ramps with 12 rockets each (total of 48 rockets), 1x 500 kg bomb in internal bombay (removal of belly fuel tank)

Ammunition types:
HE(M), HE(I), AP(T), AP(I).

Other Equipment:

EZ-42, computing gunsight

Kommandogerät, engine propeller management computer

Patin PKS 12b, course steering Autopilot

Ejection seat

Electric heating of wing leading edges for de-icing.

Heated windscreen

Layout:

 

[davebender]

Clearly it's superior to every other piston engine fighter if flown with the proper Boom Zoom tactics. In fact it might be faster then early model Gloster Meteor jet fighter aircraft.

I wonder about production cost. Do we have any data concerning man hours to build the airframe?

 

[Soren]

It was certainly faster than any Meteor in service during the war. But the Ta-152H was just as fast and did climb faster, plus it featured better maneuverability and a much higher ceiling. But the Do-335 was a more versatile a/c.

As for cost, well I'm thinking it was probably in the vicinity of the same as a Ju-88G.

 

[davebender]

Light fighter vs heavy fighter. High-low mix. Whatever you want to call it.

The Ta-152H becomes the mass production light fighter. It takes over from the Me-109 series, which is due for retirement after a decade of stellar service.

The Do-335 has serious firepower (3 x Mk103 cannon) plus a combat radius of about 700 miles with drop tanks. It also has space for a radar operator. It specializes in killing heavy bombers both at night and during the daytime.

 

[MikeGazdik]

Awesome plane. It certainly would have caused B-17's and B-24's serious trouble. I think though they would have trouble dealing with the Mustang escort. At least, the P-51's would not make it easy.

 

[timshatz]

Awesome plane. It certainly would have caused B-17's and B-24's serious trouble. I think though they would have trouble dealing with the Mustang escort. At least, the P-51's would not make it easy.

I kinda wonder if they would've sent it after the American Bombers. It has the speed and the firepower. But there were swarms of escort fighters out there waiting for anything to come up. While it had them on the speed and was probably fairly manuverable, it would've been chased by everything up there. Would they've sent it? Yes. Would it knock down bombers? Yes. Would it have survived? Probably not. Odds were just too long.

It would've made a great intruder. Even a daylight intruder. Do what the Mosquito did but in reverse. Go over England and stirr up trouble. While the RAF would've been after it, the very nature of the mission would've made and intercept difficult. Whereas the bombers were an obvious target, the Do would've had the whole island to chose to attack. Can't cover everything.

High Altitude Photo Recon, very good platform.

Ground attack? Maybe, but seems like a waste. Use the Armored up 190s for that.

 

[riacrato]

I would agree. EK 335s assessment of it in the heavy fighter role wasn't too promising. Granted the version they flew had a castrated performance, I still think they were essentially with what they said: The plane will likely perform in the early '45 air battles like the Me 410 did a year earlier: good when there's no escorts, but will get into serious trouble if intercepted.

As an intruder/nightfighter it'd be great though.

 

[FLYBOYJ]

It would have been a great "boom and zoom" fighter - plenty of room for growth into other roles. Push-pull aircraft in general are notorious for over heating problems in the aft engine, especially while on the ground, I wonder if the 335 had any such problems?

 

[davparlr]

This is a rehash of previous discussions but since we are talking about proposed aircraft, my feelings are that Germany should have spent it development efforts on the clearly superior Me-262 and maybe other jets instead of aircraft like the Ta-152, and especially the Do-335, that were not going to provide significant advantages over the latest Allied aircraft such as the P-51H, P-51M, F4U-4, and the latest Spitfire marks.

Here's a comparison of the Do-335A1/5 to the XP-72, an allied aircraft whose very successful flight test program was cancelled because the Allies were moving on in technology. If we assume that the war had continued and jets were not becoming operational, and these two aircraft, whose development was parallel, met in the skies over Europe in the summer of '45, this is how they might match up.


Empty Weight-lbs
P-72 11476
Do 16280

Loaded Weight-lbs
P-72 14433
Do 21142

Length-ft
P-72 36.6
Dop 45.6

Wingspan-ft
P-72 40.9
Do 45.3

Wing Area- ft^2
P-72 300
Do 414.4

Wing Loading- lb/ ft^2
P-72 48.1
Do 51

Power–Hp(PS)
P-72 3450
Do 4800

P/W Loaded- hp/lb
P-72 .24
Do .23

Max Airspeed-mph
P-72 480 (tested, without turbo) to 490+ (est.)
Do 474

Climb Rate-ft/min
P-72 5280
Do 4600

Ceiling-ft
P-72 42,000
Do 38,000


I think it is apparent that the Do-335 would be at a disadvantage as it is exceeded my most all performance criteria.

 

[DerAdlerIstGelandet]

I have read that the Pheil did have problems during development with the rear engine overheating. As you stated though, it is common with these types of aircraft.

 

[red admiral]

It was certainly faster than any Meteor in service during the war.

Faster than the eight prototypes and twenty Meteor Mk.Is. Now, changing over to the Meteor Mk. III in December 1944 and gave a significant speed advantage at all heights, the Do 335 only coming close at full throttle height.

I have read that the Pheil did have problems during development with the rear engine overheating.

Stability problems at high speed as well.

"One of the problems that had manifested itself as test-flying progressed was that it was found that the automatic opening of the rearoil cooler flaps caused an uncontrolled spontaneous flick which was transmitted through the lateral axis, causing the aircraft to porpoise. In order to establish the reason for this, and surmount any overheating problems with the rear engine, several tests were undertaken with the V6 fuselage "

In spite of its remarkable performance, the Do 335 failed to be seen in any numbers in Luftwaffe service. There were three main reasons for this. Firstly, the bombing of the Dornier factories which caused severe disruption to production plans; secondly the problem of the weakness of the undercarriage which was never satisfactorily solved; and thirdly, difficulties with stability. An insight into this last problem was given in a preliminary interrogation by USAAF staff of the respected Luftwaffe fighter ace, Generalleutnant Adolf Galland, on 14 May 1945:

"Galland had flown the Do 335, but although he found it a good aircraft, he believed it would require considerable improvement in design before it could be accepted as operational. As a twin engined fighter it lacked the stability required, and usually found, in such aircraft. He attributed this lack of stability to the distance between the two engines. In comparison to a single-engined fighter he stated that it handled 'too heavy'."

Dornier Do 335: The Luftwaffe's Fastest Piston-Engine Fighter by J. Richard Smith , Eddie J. Creek and Gerhard Roletschek

 

[drgondog]

If Mustangs and Tempests could successfully chase down a fighter that was 100mph faster (Me 262) why does anyone think that the Do335 would be a formidable threat to USAAF bomber fleets in 1945 - Given the coverage both for escort and sweeps?

Boom and Zoom has questionable sufficient advantage in performance to remain quasi invulnerable. There was always a high escort ~ 5000 feet above the bomners for at least one squadron over just about every wing at that stage of the war. 335 could definitely dive past to make initial attack but not sure of staying away from escorts even if after the initial attack.

It certainly would/should have been more effective than Fw 190 and me 109 but at what cost to the Me 262 deliveries?

 

[Bug_racer]

how about adding some rocket pods for quick getaway acceleration ?

 

[DerAdlerIstGelandet]

If Mustangs and Tempests could successfully chase down a fighter that was 100mph faster (Me 262) why does anyone think that the Do335 would be a formidable threat to USAAF bomber fleets in 1945 - Given the coverage both for escort and sweeps?

I have been contemplating the same thing. While I think it was a remarkable aircraft, I find it hard to believe it would have given the Luftwaffe any advantage at all.

 

[parsifal]

It has the disadvantage also of simply using two engines, instead of one, which adds to the production costs enormously.

In order for there to be no impact on serviceability rates and logistics, the Germans would need to phase out one of their other types. Since the retention of the Ta 152 and the retention of the Me 262 have already been mentioned, we also have the He 162 to consider, and a couple of other types as well, all doing basically the same job, all using different parts, fuels, ammunition, lubricants, etc etc. Luftwaffe serviceability rates would have suffered if yet another type were added to the inventory.

 

[davebender]

Once the Me-262 enters mass production it would be senseless to mass produce the Do-335 also. It you want the Do-335 in mass production then you must assume either:
a. The Me-262 program was a failure.
b. The Do-335 program begins early. Perhaps during 1937 concurrent with the Fw-190 program.

 

[FLYBOYJ]

Once the Me-262 enters mass production it would be senseless to mass produce the Do-335 also. It you want the Do-335 in mass production then you must assume either:
a. The Me-262 program was a failure.
b. The Do-335 program begins early. Perhaps during 1937 concurrent with the Fw-190 program.

How about dumping the Bf 109 and Me 110?????

 

[Shortround6]

Once the Me-262 enters mass production it would be senseless to mass produce the Do-335 also. It you want the Do-335 in mass production then you must assume either:
a. The Me-262 program was a failure.
b. The Do-335 program begins early. Perhaps during 1937 concurrent with the Fw-190 program.

There is little or no sense to an early Do-335 program as the armament available to the Luftwaffe doesn't make much sense for a tandem engine single seat fighter. The through the engine mount for the 20mm MG/FF didn't work all that well and even if they thought it would, that leaves you with a twin engine fighter armed with a single cannon and that gun with rather limited ammo capacity. Yes you can put guns in the wing but at the time the 20mm/FF used a 60 round drum. Using two engines to haul the same armamet as the 109E-3 was supposed to carry doesn't seem to good. Unless of course you put a couple of MG 17s in the wing roots in addiotion to putting them in cowl.
The Bf 110 carried 3 drums per cannon but used the radio operator/rear gunner as the drum changer. Maybe not real practical but no worse than the first Beaufighters and certainly better than being limited to a single drum per gun as a wing installation or engine installation would require.
Any guns besides the MG 17 and the MG/FF don't show up in numbers until 1941/42.

 

[MikeGazdik]

I know little about the 335, but looking at it I would assume the props counter-rotate. That being, there would have to be some tremendous torsional loads mid fuselage. That would have to cause serious problems in certain maneuvers. I would also think because of those loads the middle of the fuselage would be very intolerant of battle damage.

As a technology though, I think the engineering is just incredible!

 

[Soren]

Regarding Galland and his comments on the Do-335. Well first of all I'm not even sure he ever flew one, secondly if he did it must have been an early prototype cause according to Do-335 chief test pilot Hans Werner Lerche the Do-335 featured very light controls and the handling characteristics of the a/c were non other than excellent, the a/c featuring a fast roll rate and impressive turn performance. Furthermore Lerche says the a/c was very stable in flight, so again not sure where red admiral gets his info from, but the A-0 atleast didn't feature any of the weaknesses he claims.