the flaw of the dornier do 335 design?

[tomo pauk]

Couple of faults come to mind: With the high inertia resulting from engines at each end the unexplored (at the time) issue of roll coupling and resulting possibilities of unrecoverable departures from controlled flight is one.
...

Rear engine was closer to the CoG than to the rear prop, check out the picture at post #16 here.

 

[Shortround6]

I always thought the a/c was designed to be a fast bomber destroyer not a dogfighter.

One of the big flaws, as a fighter, was that was intended to be a schnell bomber and as such had an internal bomb bay for a 1000kb bomb load (two 500kg bombs?).
This helped dictate the size of the aircraft. As a bomber destroyer this meant there was plenty of weight carrying ability for large,powerful weapons. As a night fighter it meant you could stick the 2nd crewman in the area where the fuel tank was and move the fuel to the bomb bay area.
You still had a very large airplane (for a fighter) though. Expecting it to maneuver like a single engine fighter (even a P-47) was a forlorn hope.

The Luftwaffe may have had no real requirement for a Shell bomber by the time the design was ready but did have a pressing need for bomber destroyers so the design was adapted.

 

[BiffF15]

One of the big flaws, as a fighter, was that was intended to be a schnell bomber and as such had an internal bomb bay for a 1000kb bomb load (two 500kg bombs?).
This helped dictate the size of the aircraft. As a bomber destroyer this meant there was plenty of weight carrying ability for large,powerful weapons. As a night fighter it meant you could stick the 2nd crewman in the area where the fuel tank was and move the fuel to the bomb bay area.
You still had a very large airplane (for a fighter) though. Expecting it to maneuver like a single engine fighter (even a P-47) was a forlorn hope.

The Luftwaffe may have had no real requirement for a Shell bomber by the time the design was ready but did have a pressing need for bomber destroyers so the design was adapted.

I'm curious how it flew with all the weight / mass at both ends. Did it detract from dynamic stability, or how did it do with more violent or stressful maneuvers? It was a fighter as much as an interceptor and had the radar versions been earlier might have put a dent (size not a show stopper but...) in the night raids. Day raids would have been a bit difficult with squadrons of Mustangs in the vicinity. Any idea on endurance?

Cheers,
Biff

 

[wuzak]

It depends on the tactics they used.

If they used the high speed of the Do 335 to hit the bombers and run, the P-51s may have had a difficult time catching up.

Endurance wasn't as much as a P-51, but much better than the Me 262, and better than the Fw 190 and Bf 109.

 

[Ivan1GFP]

Thanks Ivan. Maybe the tricycle undercarriage gives the 335 a larger look. The whole airframe is high off the ground. It is a big plane. I'm about 30 miles North of the Udvar Hazy. Its fun to go, and I still like the diversity of the Air and Space down town.


I stumbled on this site from Finland:

Dornier Do 335 "Pfeil"

Hello pinehilljoe,
It sounds like we live in about the same area. These days, we only go there about once a year.
When they have Flak Bait and Heinkel 219 finished, we are sure to visit again. We could see Flak Bait being worked on when we were last there.
The link you included is very interesting. I am still exploring it.

One of the big flaws, as a fighter, was that was intended to be a schnell bomber and as such had an internal bomb bay for a 1000kb bomb load (two 500kg bombs?).
This helped dictate the size of the aircraft. As a bomber destroyer this meant there was plenty of weight carrying ability for large,powerful weapons. As a night fighter it meant you could stick the 2nd crewman in the area where the fuel tank was and move the fuel to the bomb bay area.
You still had a very large airplane (for a fighter) though. Expecting it to maneuver like a single engine fighter (even a P-47) was a forlorn hope.

The Luftwaffe may have had no real requirement for a Shell bomber by the time the design was ready but did have a pressing need for bomber destroyers so the design was adapted.

Hello Shortround6,
Even without an internal bomb bay, the Dornier 335 would have been a large aircraft.
The Daimler Benz DB 603 was a very large and heavy engine and any aircraft mounting two of them was not going to be small especially if it were to carry enough fuel to have any kind of useful range. Just a bare engine with no accessories was over a ton in dry weight.

 

[EDFN]

Some years ago, there was a longish series on the Do 335 in a german magazine about historical aircraft. One of the weakest points of this design was the complete lack of rearward visibility which made it a very bad fighter. It´s only effective fighting tactics could have been a hit-and-run one: Dive onto the bombers, strafe heavily and zoom up again into the sun. No dogfighting, please, because this required constant visual all-round perception. IIRC, somobody wrote about it epitomizing the swan song of piston driven fighters.

 

[Tom Fey]

Chuck Yeager flew the Do-335 and is on record as saying it was "... a can of worms. A maintenance nightmare." I don't have anything more specific than that, but perhaps there is a Army Air Force flight test report hiding in the archives somewhere.

 

[Milosh]

Myth about the Do335 was that a pilot lost his arms when he jettisoned the canopy.

 

[GrauGeist]

There was an account by Clostermann where he and his flight encountered a Do335 that was at tree-top level, late in the war.
As he and his flight tried to get into position to down it, the Do335 pulled away from their Tempests at a good rate of speed - and the Tempest was nearly as fast as the P-51D.

 

[Tony Kambic]

I've been a volunteer at Uvar-Hazy since it opened and have always been fascinated by the Do335. I've been very fortunate to be volunteering in the restoration and conservation areas the past few years.

There have been discussions around the museum docents and staff on the Do335. One sad thing is that the original rear spinner was missing and the one created in Oberpfaffenhofen by the Dornier staff during the rebuild is not the exact dimensions. Compare photos and you will see the original was more extended. Also, this aircraft is displayed with original 'strut collars'. Apparently ground crews used these to eliminate problems raising the aircraft since the aircraft was large and late war field damage led to collapse. The F4 phantom in Hazy also has native strut collars among other aircraft.

Last, there has always been some discussion about the relationship of the 'wing' design of the Do335. Legend has it that it may have been an influence on the P16, which Bill Lear was involved with and that carried over to the Lear Jet. For you to decide.

Tony

 

[davparlr]

The real problem was that it was already obsolete. By the time the Do 335 would become operational, Allied jets, P-80, Meteor, were quickly maturing. Even without jets the Do 335 was equaled or outclassed by late war Allied designs, specifically the XP-72, which had completed impressive flight test and was in production when cancelled due to war progress. It was as powerful at all altitudes (using only one engine, even the P-47M/N was more powerful at 30,000 ft than the Do 335), about 5000lbs lighter, was faster, a 4500 ft. higher ceiling, and, most likely, more maneuverable. As usual, Germany spent too much time chasing concepts rather than building already proven designs, Ta 152, Me 262, other jets.

 

[YF12A]

Dave, have to respectfully disagree with you about the XP-72. Yes, heck of an aircraft, but... Probably the best prop fighter to get to a War Zone but not see combat, and was made in large numbers (555) was the P-51H. It could do everything the 72 could do which was more than a match for anything else already out there short of the Me-262, was already in production, used far less resources to make and use, fuel efficient, MPG on the XP-72, ouch!, was a lot less complex and far more maintainable and I'm sure a lot less expensive over all. The Merlin was a Mature engine, the R-4360 was not. My Dad told me they had problems with the Corncob from his times at American Overseas Airlines, after WW2, with the first batch of Stratocruisers' and these engines were being operated to Civilian standards, not in a War Zone in Combat. Heck, SAC had problems with them in the '50's with the B-36. How many times I have been told by former B-36 crewmen it was totally not unusual to take off with 6 running and return with only 5, sometimes 4, still running. I know, unusual backwards installation etc, but still, in a single engine Fighter a Decade earlier in Combat, no thanks!

About the DO-335. I am a Native of Alexandria VA. I have been going to the Air and Space Museums since I could walk, early '60's back when I could barely reach out and touch Yeagers' Bell X-1 sitting on the ground, to Silver Hill, the NASM DC and U/H on literally hundreds of times. My point, I'm now 6'9" and have literally grown up around all of these aircraft all my life and the DO-335 is still Freaking HUGE compared, to me, to any other fighter, P-47 included. It's like F-4 Phantom size! My Dads' opinion on the 335 besides having 2 engines on a fighter was from a maintenance side was simple. The higher up off the ground, the harder and more time consuming it is to work on. He absolutely hated the DC-10, I remember the first one we saw together when I was young. He pointed to the tail mounted engine and asked me, "what's wrong here? ". I said I didn't know. He asked, how do you get to that engine without a lot of new and expensive equipment unique to this plane! In my Decades of flying on A/A, I was forbidden to fly on one and I didn't disagree.

 

[davparlr]

Dave, have to respectfully disagree with you about the XP-72. Yes, heck of an aircraft, but... Probably the best prop fighter to get to a War Zone but not see combat, and was made in large numbers (555) was the P-51H. It could do everything the 72 could do which was more than a match for anything else already out there short of the Me-262, was already in production, used far less resources to make and use, fuel efficient, MPG on the XP-72, ouch!, was a lot less complex and far more maintainable and I'm sure a lot less expensive over all. The Merlin was a Mature engine, the R-4360 was not. My Dad told me they had problems with the Corncob from his times at American Overseas Airlines, after WW2, with the first batch of Stratocruisers' and these engines were being operated to Civilian standards, not in a War Zone in Combat. Heck, SAC had problems with them in the '50's with the B-36. How many times I have been told by former B-36 crewmen it was totally not unusual to take off with 6 running and return with only 5, sometimes 4, still running. I know, unusual backwards installation etc, but still, in a single engine Fighter a Decade earlier in Combat, no thanks!

About the DO-335. I am a Native of Alexandria VA. I have been going to the Air and Space Museums since I could walk, early '60's back when I could barely reach out and touch Yeagers' Bell X-1 sitting on the ground, to Silver Hill, the NASM DC and U/H on literally hundreds of times. My point, I'm now 6'9" and have literally grown up around all of these aircraft all my life and the DO-335 is still Freaking HUGE compared, to me, to any other fighter, P-47 included. It's like F-4 Phantom size! My Dads' opinion on the 335 besides having 2 engines on a fighter was from a maintenance side was simple. The higher up off the ground, the harder and more time consuming it is to work on. He absolutely hated the DC-10, I remember the first one we saw together when I was young. He pointed to the tail mounted engine and asked me, "what's wrong here? ". I said I didn't know. He asked, how do you get to that engine without a lot of new and expensive equipment unique to this plane! In my Decades of flying on A/A, I was forbidden to fly on one and I didn't disagree.

The P-51H was indeed one of the superb late model allied aircraft including the P-47M/N (with its amazing 2800 hp at 33k ft) and probably some Brit models. Performance of the P-51H did tend to drop off rather quickly above 25k ft. but just about unbeatable at or below that. I don't have good data on the XP-72 other than top speed was 20 mph faster than the P-51H and that it had a huge supercharger (not turbocharger) and was well liked by test personnel. All of these planes would be formidable opponents to the Do 335.

 

[BiffF15]

Dave, have to respectfully disagree with you about the XP-72. Yes, heck of an aircraft, but... Probably the best prop fighter to get to a War Zone but not see combat, and was made in large numbers (555) was the P-51H. It could do everything the 72 could do which was more than a match for anything else already out there short of the Me-262, was already in production, used far less resources to make and use, fuel efficient, MPG on the XP-72, ouch!, was a lot less complex and far more maintainable and I'm sure a lot less expensive over all. The Merlin was a Mature engine, the R-4360 was not. My Dad told me they had problems with the Corncob from his times at American Overseas Airlines, after WW2, with the first batch of Stratocruisers' and these engines were being operated to Civilian standards, not in a War Zone in Combat. Heck, SAC had problems with them in the '50's with the B-36. How many times I have been told by former B-36 crewmen it was totally not unusual to take off with 6 running and return with only 5, sometimes 4, still running. I know, unusual backwards installation etc, but still, in a single engine Fighter a Decade earlier in Combat, no thanks!

About the DO-335. I am a Native of Alexandria VA. I have been going to the Air and Space Museums since I could walk, early '60's back when I could barely reach out and touch Yeagers' Bell X-1 sitting on the ground, to Silver Hill, the NASM DC and U/H on literally hundreds of times. My point, I'm now 6'9" and have literally grown up around all of these aircraft all my life and the DO-335 is still Freaking HUGE compared, to me, to any other fighter, P-47 included. It's like F-4 Phantom size! My Dads' opinion on the 335 besides having 2 engines on a fighter was from a maintenance side was simple. The higher up off the ground, the harder and more time consuming it is to work on. He absolutely hated the DC-10, I remember the first one we saw together when I was young. He pointed to the tail mounted engine and asked me, "what's wrong here? ". I said I didn't know. He asked, how do you get to that engine without a lot of new and expensive equipment unique to this plane! In my Decades of flying on A/A, I was forbidden to fly on one and I didn't disagree.

YF12A,

I follow your train of thought regards MX on various A/C however I thought I would offer another perspective. The A-10 sits high above the ground, motors included, making MX difficult. However it was done for a reason or reasons. First, with the wing high enough above the ground it makes for easier arming or weapons loading and or uploading or downloading fuel tanks. Also with the motors high up on the fuselage a gear up landing will result in little to nod FOD being ingested. The Eagle needed to sit high enough to carry a 4000lb fuel bag under the centerline, which results in the gear being taller, and the plane sitting higher. The DC-10 was built around the FAA limit of three engines being required for long distance overwater flight. With that in mind, you will either put the second engine in the tail or fuselage. If you put it in the fuselage where do you put the APU (in the DC10 it's in the tail cone area). Yes the plane had an Achilles heel as seen with UAL232, however that was fixed. If it was such a bad design why are so many still flying along with it's brother the MD11. I worked as a F/E on them and would have no problem with my family flying on it (as long as it was properly maintained but that applies to any airplane).

All designs are a series of compromises. I think the B777 was the first aircraft to be designed with a real maintainer in mind, not one who has 4 foot long arms with incredibly strong but tiny hands. I have changed out boxes / gauges in the cockpit of an Eagle, as well as hydraulic pumps, and am firmly convinced that ZERO consideration was given to to the individual who would actually work on it (doesn't mean I don't love it though).

Cheers,
Biff

 

[GrauGeist]

Two (of several) formidable late-comers that could have handled the Do335, would have been the Hawker Sea Fury and Martin-Baker MB.5, too.

 

[GrauGeist]

If it was such a bad design why are so many still flying along with it's brother the MD11.

Whatever the pros and cons of the DC-10 may be, it was a glorious sight here during the Carr Fire!

(stock photo)

 

[davebender]

I always thought the a/c was designed to be a fast bomber destroyer not a dogfighter
This is only speculation but I believe recon would be the best role. Think SR-71. Fast, long range and almost impossible to intercept.

 

[Ivan1GFP]

The real problem was that it was already obsolete. By the time the Do 335 would become operational, Allied jets, P-80, Meteor, were quickly maturing. Even without jets the Do 335 was equaled or outclassed by late war Allied designs, specifically the XP-72, which had completed impressive flight test and was in production when cancelled due to war progress. It was as powerful at all altitudes (using only one engine, even the P-47M/N was more powerful at 30,000 ft than the Do 335), about 5000lbs lighter, was faster, a 4500 ft. higher ceiling, and, most likely, more maneuverable. As usual, Germany spent too much time chasing concepts rather than building already proven designs, Ta 152, Me 262, other jets.

Hello davparlr,
This isn't a bad discussion on what Allied counters to the Dornier 335 would have been, but I believe it is also a bit off the mark.
You are thinking about why the Dornier 335 would not have been quite as effective as the numbers might indicate.

Think instead from the German viewpoint in 1942. If you want an aircraft with great performance, you need power and there are not sufficiently powerful engines available. As it turned out, there never would be, but that was not known in 1942.
A lot of the late war German designs depended on the successful development of more powerful engines but even moderate improvements such as the DB 603G did not enter production. The DB 610 did not work as well as expected. The JuMo 222 never reached production. The JuMo 213 eventually had its bugs worked out, but at this time the engineers still had not figured out why it was breaking crankshafts.
If you can't get sufficient power with one engine, then going with two sounds pretty reasonable. A tandem arrangement is pretty good from an aerodynamic standpoint and Dornier already had experience with such configurations.

Unlike the United States, Germany never had the reliable high powered engine like a C series R-2800 that could be used in a simple single engine fighter.

- Ivan.

 

[Glider]

To be honest, it was too big, too complex, too unmaneoverable, too expensive and too late

 

[BiffF15]

In the night fighter variant I might consider it a peer of the P-61. I'm surprised that more weren't earmarked for that role as they could be used day or night against the bomber streams.

Cheers,
Biff