Dornier 219 What If

Dornier had all sorts of experience with liquid cooled tandem engine aircraft. Why would a heavy bomber be any different then the Do-26 seaplane?

Dornier Do 214 Luft '46 entry


Powered by eight DB613 24 cylinder engines. A tandem engine Bomber A powered by four Jumo 211 engines would be puny by comparison.

Again, just seaplanes or flying boats for Dornier. Did they just not get contracts for land-based planes after the Do19 fiasco?

Ar-196 was the primary German ship based seaplane.

BV-138 was the primary German long range seaplane.

He-115 was the primary German seaplane torpedo bomber.

Do-17 light bomber and Do-18 seaplane were phased out of production by early 1941.
.....Dornier couldn't obtain enough engines for the Do-217 bomber program. It was the logical replacement for the Do-17 level bomber.
.....Do-26 seaplane was not allowed to enter mass production. It was the logical replacement for the Do-18.

Ju-288 was selected for Bomber B program rather then the equally capable Do-317.

Do-335 tandem engine light bomber program specifications were changed several times, preventing that aircraft from entering mass production.

It appears to me Dornier had few friends within the German government. Otherwise it's difficult to explain why orders for Dornier aircraft dried up after 1940.

The Do17 was supposed to be phased out in 1938, but Dornier lobbied to get it continued, successfully keeping it around until 1941. So he had some influence it seems.

Luftwaffe only had 787 He-111s as of September 1939. Ju-88 didn't enter mass production until late 1939.

IMO the Do-17 probably remained in production until 1941 because Germany had nothing to replace it with. If the Ju-88 had entered mass production two years earlier then Do-17 production would have ended during 1938.

Alright, somewhat separate question. Could the Do19 be redesigned with the push-puller configuration and be production ready in 1939? That would mean a total wing redesign, a fuselage enlargement, a tail and nose assembly redesign. Pretty much a total overhaul. I think it would take about 1 year for the full redesign to finish, about a 10-12 months to produce a prototype and about a year of testing/further development.
So assuming a start in July 1936 when the halt order came down for Do19 development and Dornier convinces the RLM to authorize further development, the redesign would be ready around August 1937. The prototype would be ready in June-August 1938. The green light for production could either happen after the prototype is demonstrated as basically sound even if it needs some tweeks over the next year. Still, most new designs in WW2 required 2 years of development/testing to be production ready, the major exception being the Do217, which to a degree was an outgrowth of the Do17. Could this abbreviated timeframe work with the Do19?

17 April 1936. RLM request for Bomber A.
…..Top speed of 335mph.
…..Operational radius of 1,000 miles with a 2,000kg payload.
…..Operational radius of 1,800 miles with a 1,000kg payload.
…..Capable of shallow angle bombing. Later modified to 60 degree angle.
…..Expected to be operational by 1940.

IMO Do-19 is the wrong approach. Start with the much better Do-217 which historically could almost meet Bomber A specifications powered by a pair of DB603 engines.

Historical design of the Do-217 began during 1938. However it was based on the Do-17 which first flew during 1934. Move Do-217 airframe design forward two or three years. Power it with a pair of tandem Jumo 211 engine pods which will eliminate the historical Do-217 engine shortage and provide quite a bit more total power. You need more internal fuel capacity to meet the range requirement which may result in a slightly larger aircraft.

Yeah, the wings would have to be expanded too to make sure the engines were far enough apart. I have to think over this idea, because there are going to have to be several changes of the OTL model, which will pretty much make it a Do219.

The Bomber A spec could have been met by the B17...which the Do19 could have turned into by 1939-40 with development and testing.

I disagree. B-17 cannot meet Bomber A speed or range with payload requirements. The 1943 B-17G comes close but by then Germany had the superior He-177A3 and He-177A5 in production.

Factsheets : Boeing B-17E
B-17E entered service during 1941.
317mph max speed.
3,200 miles max ferry range.

You're right, the speed is the only thing it cannot keep up with when using the required payload. But otherwise it meets the spec.
But I'm for the He177B or Do219. The question is whether either could be ready in time to make a difference in the Blitz.

I agree.

He-177B (4 x Jumo 211 engines) recommended by Heinkel during 1938 had potential to be the best heavy bomber of WWII and it probably could have been in service by 1941. Late war version powered by DB603 or Jumo 213 engines would have rivaled the B-29 in performance. I believe there was even a He-177B prototype powered by 2,500 hp Jumo 222 engines.

However it would still have been interesting to see a Dornier tandem engine bomber design. Do-217 was an excellent airframe.

Certainly. The mockup was ready in mid-1937, but was delayed by modifications ordered by the Luftwaffe. At that point they could have also requested changes to the engines, as the 2 props predated the dive bombing requirement, which appeared in November 1937 when the final mockup was ready. It the original plan was stuck to, the first prototype would have flown in late 1938 and probably been production ready in late 1940, to enter service in June-July 1941.

As to the Do217 frame with tandem engines, the airframe would have had to have been modified to handle the significantly larger wings that would have been required. So the airframe would have ended up much larger and not been the Do217 anymore, but something like a Do317 or Do219. It would have had to have been so much larger than it would then make sense to have a bomb bay that could take 6 tons of bombs and been the rival to the He177B.

airframe would have ended up much larger and not been the Do217 anymore, but something like a Do317

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Data from Wikipedia.

Wingspan.
19 meters. Do-217J (BMW801 engines).
20.63 meters. Do-317A (DB603 engines).
26 meters. Do-317B (DB610 engines).

Length.
18.2 meters. Do-217J.
16.8 meters. Do-317.
.....Not sure why Do-317 is shorter then Do-217. Could that be a misprint?

A tandem pair of Jumo 211 engines should weigh about the same as a paired DB610 engine. So I think the Do-317B represents what our hypothetical aircraft would look like. Except for greater wingspan it's still pretty much a Do-217.

Minor point. It seems like by now we are talking about an aircraft that has essentially no similarity to the original Do-19, and which is not even descended from it. The discussion is about a purely hypothetical Dornier aircraft that, if anything, is an extrapolation of the Do-217 using tandem push-pull engines developed from the concepts used on floatplanes. Very unlikely it would be called Do-219, methinks. How 'bout calling it a Do-417 or taking another approach and making it a landplane adaptation of one of the proposed Dornier large flying boats. Actually, it seems to me to be that forthright accelerated development of the He-177B or He-277 makes the most sense.

If design work begins during 1935 or 1936 it would be earlier then the historical Do-217. So it would probably receive the Do-217 designation.

I meant the width of the wings (front to back), not the length. The wings would of course be strong enough to handle two Jumos, just as they would two DBs, but they would need to be wide (deep?) enough to one directly behind the other on each side.
Junkers Jumo 211 - Wikipedia, the free encyclopedia

Length: 1,768 mm (69.61 in)

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Each is nearly 6ft long, so the wings would also need to be about 14ft or so long/deep to take both engine and give enough room between engines so they don't over heat, but also to give the propellors enough room so that the 'backwash' of the front propellor doesn't disrupt the rear propellor's airflow.

davebender said:

If design work begins during 1935 or 1936 it would be earlier then the historical Do-217. So it would probably receive the Do-217 designation.

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Why? The Do217 was a development of the medium bomber the Do17. Hence the advanced designation of 217. A strategic bomber would be the advanced version of their previous version, enough though it has nothing to do with it, just as the Do217 structurally had little to do with the Do17. So IMHO it makes more sense to go along with the next step in the 19 series, as it was the Dornier strategic bomber series. Unless they just wanted to go for an unassigned number like the Do30 or something like that.

wiking85 said:

Each is nearly 6ft long, so the wings would also need to be about 14ft or so long/deep to take both engine and give enough room between engines so they don't over heat, but also to give the propellors enough room so that the 'backwash' of the front propellor doesn't disrupt the rear propellor's airflow.

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And there you have one of the problems with the tandem engine.

You have to decide on all but the largest of planes before metal is cut, if you are using 4 tractor engines ( including coupled engines like the DB 606/610) or two tandem engines. The tractor engines are all forward of the main spar and forward of the center of gravity, while the rear engines in the tandem are aft of the main spar and aft of the center of gravity. On anything but the largest of aircraft ( like big flying boats) ADDING a pair of engines aft of the main spar is going to call for a lot of redesign.
Or teying to change from 4 tractors to to two tandem nacelles. If you need more room between the props you can use extensions shafts on the rear engines as was done on the DO-26.

another choice that has to be made fairly early in the design process is if flaps are going to be used to assist take-off. In the early to mid 30s NOBODY used flaps for take off, in the early 30s many aircraft did not use flaps for landing The P-26 was first produced with out them although later versions had them and they were retro fitted to the earlier planes. Early flaps were little more than drag flaps in some cases ( including the earlier Spitfire), that provided no lift but steepened the landing approach. When flaps were arranged to lower a small amount (15-40 degrees?) instead of 70-90 degrees they could be used for more lift when taking-off. Putting a propeller right in back of of a lowered flap, even a moderately lowered one is going to do serious things to the airflow through the prop and the thrust.



Engine/props are raised but I hope show the idea, drooping flaps could have a rather negative effect on thrust. Not a deal breaker but you do have to decide while building the plane if it takes of on thrust or on lift from wing/flaps.

The Germans ( and a few others) often complicated things to great extent in order to save 2-4% in drag. Tandem engines do make sense in some installations like the Do 18 flying boat (and numerous copies), you want the engines and props high up in order to keep them out of the spray, a central location centers the weight and improves roll. being able to stand on the hull or wing while working on the engines ( or reach them in flight) makes things easier for maintenance, especial if afloat and away from a land base.

One engine on each wing. Third engine in rear fuselage with prop aft of the tail (i.e. similiar to Do-335 rear engine). This arrangement leaves nose free for bombardier position. Might need the 1,750 hp DB603 engine to provide enough total power with only three engines.

Great idea! The Do217 gets changed only in that it has another engine in the pusher configuration. That way it can run on three Jumo 211's or DB601's until the DB603 arrives. Then it has more power than IOTL.
The only problem is how far toward the ground the propellor is during landing and take off.

Looking at this though shows that it would need special landing gear to keep it further off the ground like the tricycle landing gear of the Do335...which was expensive and difficult to produce and maintain...