Why Did the He 177 Fail?

[GregP]

I thought there were six, too:
1. Do 26A (D-AGNT Seeadler) and Do 26A (D-AWDS Seefalke.Civil planes.
2. Do 26B (D-ASRA Seemöwe). Civil plane.
3. Do 26C V1. V2, and V3. Military planes with Jumo 205D engines.

I found a reference to a seventh one as "D" (I assume a Do 26D) but many more sources that say six was the entire population.

What do you have as the entire population, Capt. Vick?

 

[nuuumannn]

perfected He-177A heavy bombers

'Perfected' is not a word I'd use to describe the He 177A. It was a good performer, but the engine fires were not the only issue with the aircraft that prevented it from becoming anything greater than an 'also-ran'.

Comparison with the Manchester and Lancaster is apt, as the Manchester suffered a raft of issues with its electrical systems, aerodynamic problems that caused bad handling - that gawdawful Fraser-Nash mid upper turret and inadequate vertical tail surface area, but the majority of its problems were solved in the Manchester 1A, which benefitted from the design work needed to create the Manchester III, including the larger tail fins and lower profile mid upper turret. Even the Vulture's problems were cured before the Manchester III entered full scale production as the Lancaster. This is where the Manchester could be argued to have been a successful design, as its airframe went largely unchanged to become the Lancaster; the first Lanc, BT308 was actually a Manchester airframe removed from the production line and modified.

The big difference between the Manchester/Lancaster and the He 177 however, is not the nature of the issues that beset the types, but the time frame in which the change from innovative failure to successful design took place, also the large number of Lancasters built, against which the He 177 could not compete in comparison. Because Manchesters were already moving down production lines, the change to the Lancaster was not as disruptive as it could have been if too many changes to the design were required. The best bits about the Lancaster - apart from its engines were already incorporated into the Manchester.

If you want to make a comparison across a period of time that matches the He 177, then look no further than the Handley Page Halifax. It wasn't for almost three years after it first flew that it became the sort of aircraft that it should have been to begin with in the Halifax III, ironically, its benchmark was the aircraft that the Air Ministry claimed had to be better than the Halifax before it would contemplate continuing its production - the Lancaster. The difference between the Halifax and the He 177 being the industry that supported it; at the time the British needed all the Halifaxes and Stirlings it could get its hands on - mediocre design and performance notwithstanding - the German need for the He 177 never really seemed as pressing; its use in attacks against the UK were desultory and without measurable result; their planning seemed to be more of a hollow gesture rather than a serious campaign.

The German hierarchy and way of doing things - as identified by others here was perhaps the biggest stumbling block to its success; this is also identified by contemporaries - Hans Werner Lerche states this as being a big cause of its failure, although he didn't state the airframe was 'great', merely that it had pleasant handling characteristics; here's paragraphs from his book Luftwaffe Test Pilot on the He 177 compared to the B-24 and why it failed.

"If I were asked whether I would prefer to have flown a Liberator with its not completely satisfying flying characteristics or a Heinkel He 177 with practically faultless characteristics but unreliable powerplants, I must confess that I would have preferred to pilot the Liberator, to say nothing of the superior numbers and the fighter escort. In fact, the He 177 with the longer fuselage was not difficult to fly at all, and the version with the separate engines could have made quite a decent combat aeroplane. Perhaps an aircraft combining the new He 177 airframe with the excellent American high altitude engines with their exhaust driven turbo superchargers would have made the ideal bomber at the time."

"I myself see other and deeper reasons, rather than the fault of the engineers, for the debacle with the He 177 and other bad planning on the part of the Luftwaffe. The politically false assessment regarding the entry into the war of Great Britain and later the USA, and the underestimation of the Soviet military power, made the development of a long range bomber appear superfluous at that time. Then, when the He 177 became available and held promise of evolving into an efficient combat aircraft, the State Ministry of Aviation insisted that the He 177 also had to be capable of diving attacks to a far greater extent than planned. This led to a whole series of unnecessary structural alterations and reinforcements which, in turn increased weight."

"In the meantime, the first military successes had been achieved and the Russian campaign also appeared to be running to plan. It seems it was not just a bad joke that, for example, the supply of agricultural machinery to the occupied regions of the Soviet Union - and there was even talk of erecting folk museums! - ranked higher than the needs of the Luftwaffe on the priority list. Consequently not only the He 177 but also several other aircraft developments were postponed, or at least delayed."

 

[GregP]

Folk museums? Ha ha ha ha ...


How lucky could the Allies get? Museums with a higher priority than the Air Force ina cou try at war! It boggles the mind.

 

[nuuumannn]

Yep, bizarre; only in Nazi Germany. The nazis' view of history was cruelly clinical; destroy the offending abscess, then preserve its memory by erecting a museum to it. They even planned a Jewish museum once they had wiped them out.

 

[SpicyJuan11]

'Perfected' is not a word I'd use to describe the He 177A. It was a good performer, but the engine fires were not the only issue with the aircraft that prevented it from becoming anything greater than an 'also-ran'.

Comparison with the Manchester and Lancaster is apt, as the Manchester suffered a raft of issues with its electrical systems, aerodynamic problems that caused bad handling - that gawdawful Fraser-Nash mid upper turret and inadequate vertical tail surface area, but the majority of its problems were solved in the Manchester 1A, which benefitted from the design work needed to create the Manchester III, including the larger tail fins and lower profile mid upper turret. Even the Vulture's problems were cured before the Manchester III entered full scale production as the Lancaster. This is where the Manchester could be argued to have been a successful design, as its airframe went largely unchanged to become the Lancaster; the first Lanc, BT308 was actually a Manchester airframe removed from the production line and modified.

The big difference between the Manchester/Lancaster and the He 177 however, is not the nature of the issues that beset the types, but the time frame in which the change from innovative failure to successful design took place, also the large number of Lancasters built, against which the He 177 could not compete in comparison. Because Manchesters were already moving down production lines, the change to the Lancaster was not as disruptive as it could have been if too many changes to the design were required. The best bits about the Lancaster - apart from its engines were already incorporated into the Manchester.

If you want to make a comparison across a period of time that matches the He 177, then look no further than the Handley Page Halifax. It wasn't for almost three years after it first flew that it became the sort of aircraft that it should have been to begin with in the Halifax III, ironically, its benchmark was the aircraft that the Air Ministry claimed had to be better than the Halifax before it would contemplate continuing its production - the Lancaster. The difference between the Halifax and the He 177 being the industry that supported it; at the time the British needed all the Halifaxes and Stirlings it could get its hands on - mediocre design and performance notwithstanding - the German need for the He 177 never really seemed as pressing; its use in attacks against the UK were desultory and without measurable result; their planning seemed to be more of a hollow gesture rather than a serious campaign.

The German hierarchy and way of doing things - as identified by others here was perhaps the biggest stumbling block to its success; this is also identified by contemporaries - Hans Werner Lerche states this as being a big cause of its failure, although he didn't state the airframe was 'great', merely that it had pleasant handling characteristics; here's paragraphs from his book Luftwaffe Test Pilot on the He 177 compared to the B-24 and why it failed.

"If I were asked whether I would prefer to have flown a Liberator with its not completely satisfying flying characteristics or a Heinkel He 177 with practically faultless characteristics but unreliable powerplants, I must confess that I would have preferred to pilot the Liberator, to say nothing of the superior numbers and the fighter escort. In fact, the He 177 with the longer fuselage was not difficult to fly at all, and the version with the separate engines could have made quite a decent combat aeroplane. Perhaps an aircraft combining the new He 177 airframe with the excellent American high altitude engines with their exhaust driven turbo superchargers would have made the ideal bomber at the time."

"I myself see other and deeper reasons, rather than the fault of the engineers, for the debacle with the He 177 and other bad planning on the part of the Luftwaffe. The politically false assessment regarding the entry into the war of Great Britain and later the USA, and the underestimation of the Soviet military power, made the development of a long range bomber appear superfluous at that time. Then, when the He 177 became available and held promise of evolving into an efficient combat aircraft, the State Ministry of Aviation insisted that the He 177 also had to be capable of diving attacks to a far greater extent than planned. This led to a whole series of unnecessary structural alterations and reinforcements which, in turn increased weight."

"In the meantime, the first military successes had been achieved and the Russian campaign also appeared to be running to plan. It seems it was not just a bad joke that, for example, the supply of agricultural machinery to the occupied regions of the Soviet Union - and there was even talk of erecting folk museums! - ranked higher than the needs of the Luftwaffe on the priority list. Consequently not only the He 177 but also several other aircraft developments were postponed, or at least delayed."

My mistake, I admit I did not read his report myself, but I got my info from this post from a previous thread http://www.ww2aircraft.net/forum/polls/17-vs-177-vs-lancaster-11308.html::

Hi B-17engineer,

The German test pilot Werner Lerche considered the airframe of the He 177 excellent, but after flying a captured B-24 which he didn't like much, he said that he'd have preferred a He 177 with the reliable, turbo-supercharged B-24 engines.

He also flew a captured B-17 and enjoyed it so much that he improvised a low-level airshow over a Luftwaffe field. He considered it so docile that it could give a "misleading" impression of great manoeuvrability Sheer inertia took its toll, which is the reason for the "misleading" bit of his comment ... but he considered the B-17's flying qualities equal to that of the Heinkel He 111, which appears to have had a great reputation as a pilot's aircraft in the Luftwaffe.

So much for the "enemy" perspective ... I hope that as a B-17 enthusiast, you'll find it interesting!

Regards,

Henning (HoHun)

 

[SpicyJuan11]

Yep, bizarre; only in Nazi Germany. The nazis' view of history was cruelly clinical; destroy the offending abscess, then preserve its memory by erecting a museum to it. They even planned a Jewish museum once they had wiped them out.

Yes it was, but to reiterate what was said in the soviet thread, could we please keep this discussion to the He 177 and not digress into a discussion of the politics of the Reich? Many thanks.

 

[SpicyJuan11]

Sorry, double post.

 

[nuuumannn]

No worries Spicy Juan, not so much a criticism of what you said, more to clarify what Lerche meant and also to emphasise that although the He 177 might have had promise, there were far too many negative factors influencing its design and conception that meant it was only ever going to achieve mediocrity. Lancaster, B-17 and B-24 are in a different league; their production and subsequent careers are testament to this and starkly highlight the differences between them and the He 177.

(You don't need to repeat yourself, I heard you the first time )

 

[GregP]

The He 177 WAS part of the politics of the Reich.

 

[Koopernic]

Its partly just plane bad luck. Lets look at the Manchester/Lancaster

The Manchester was introduced into RAF service in November 1940. It was overweight and therefor underpowered. There was no hope of strengthening the Vulture engines bearings in a reasonable time so 4 separate Merlin engines inside of Beufighter power eggs were installed on a modified wing. The Lancaster thus entered service in February 1942.

Hence the British took 15 months to recognise and fix the Manchester/Lancaster problem.

The He 177 entered service as the He 177A1 in mid 1942 to late 1942 about 18 months after the Manchester. It has experienced delays for structural reasons as well as engine issues. It was a more ambitious and advanced design than the Lancaster/Manchester in regards to range and speed.

Had the problems with the engines been regarded as insurmountable and 4 separate engines fitted from that point on a 15 month period would imply a 4 engine He 177B could be available in late 1943. It seems the fix was always just around the corner. With pilot training, good maintenance maritime patrol He 177 achieved acceptable engine MTBO of 220 hours by March 1944.

The Luftwaffe just didn't have enough time to recognise the problem and alter the aircraft because it had been delayed till mid 1942. If the 'disaster'had of happened earlier the drastic action might have been taken.

Its issues needed to be recognised during testing as insurmountable and radical action taken in Mid 1941 or so irrespective of cost.

 

[Denniss]

The DB 606 engine had always been OK, it was the problematic tight installation causing the major problems/fires. The DB 610 engine in use from the A-3 on had a far better installation but introduced its own set of issue owing to the oil problems in the basic DB 605 source engine (fixed mid to late 43).
With proper maintenance equipment and training + proper pilot training the He 177 A-3 could have been put to good use in later 43. Both Luftwaffe and Heinkel failed in this, missing documentation, training and equipment.

 

[parsifal]

It depends on which mark of the He 177 we are talking about. The prototypes had so many faults it is difficult to catalogue them all. The A-1 series, which was the main 'operational" type to the end of 1942 was the type to which most of the post war criticisms had serious engine, fuel system and structural issues in the wings, which I will get back to in a minute. The A-3 had less problems and the A-5 sub type was actually a pretty good a/c, but did not enter large scale service in the winter of 1943-4. Despite having largely solved the massive technical issue that dogged this a/c losses for the A-5, used mostly in the anti-shipping role, remained high and losses to non-combat causes still remained the highest single cause for losses. Some of the aircrafts reliability problems remained with it until the end really.

Returning to the A-1, some commentators have commented as follows regarding the A-1 "despite the considerable background of test and development, the A-1 proved unacceptable for operations". A Rechlin report dated October 9 1942 states "The examination has shown that the strength of the wings is less than 1/3 those calculated by the company. The reason for this is the uneven rigidity of the individual members with consequent deformation under load. This condition was not recognised by the company at the proper time, the failure tests having been undertaken too late in view of the size of the structure".

The minutes of a Generalluftzeugmeister meeting held a week later included the following comment "He (Heinkel) is aware of the difficulties expereienced with the He177. He is aware that the most significant problems are associated with insufficient testing". This, after more than two years of flight trials and numerous losses to the protoypes.

The basic problems are associated with the engine couplings, the leaking fuel system, the poorly designed engine manifolds , poor design in the wing struts and fasteners. These are not minor issues for the aircraft and the basic problem, in my opinion was that it was an aircraft with so many new innovations, a procurement apparatus at war with the company, and fluctuating and listless interest in the whole project by the Luftwaffe hierarchy. Its problems, in other words were very deep seated and not just the result of technical over reach

 

[SpicyJuan11]

The He 177 WAS part of the politics of the Reich.

GregP, please, you know what I meant.

 

[SpicyJuan11]

The DB 606 engine had always been OK, it was the problematic tight installation causing the major problems/fires. The DB 610 engine in use from the A-3 on had a far better installation but introduced its own set of issue owing to the oil problems in the basic DB 605 source engine (fixed mid to late 43).
With proper maintenance equipment and training + proper pilot training the He 177 A-3 could have been put to good use in later 43. Both Luftwaffe and Heinkel failed in this, missing documentation, training and equipment.

It depends on which mark of the He 177 we are talking about. The prototypes had so many faults it is difficult to catalogue them all. The A-1 series, which was the main 'operational" type to the end of 1942 was the type to which most of the post war criticisms had serious engine, fuel system and structural issues in the wings, which I will get back to in a minute. The A-3 had less problems and the A-5 sub type was actually a pretty good a/c, but did not enter large scale service in the winter of 1943-4. Despite having largely solved the massive technical issue that dogged this a/c losses for the A-5, used mostly in the anti-shipping role, remained high and losses to non-combat causes still remained the highest single cause for losses. Some of the aircrafts reliability problems remained with it until the end really.

Returning to the A-1, some commentators have commented as follows regarding the A-1 "despite the considerable background of test and development, the A-1 proved unacceptable for operations". A Rechlin report dated October 9 1942 states "The examination has shown that the strength of the wings is less than 1/3 those calculated by the company. The reason for this is the uneven rigidity of the individual members with consequent deformation under load. This condition was not recognised by the company at the proper time, the failure tests having been undertaken too late in view of the size of the structure".

The minutes of a Generalluftzeugmeister meeting held a week later included the following comment "He (Heinkel) is aware of the difficulties expereienced with the He177. He is aware that the most significant problems are associated with insufficient testing". This, after more than two years of flight trials and numerous losses to the protoypes.

The basic problems are associated with the engine couplings, the leaking fuel system, the poorly designed engine manifolds , poor design in the wing struts and fasteners. These are not minor issues for the aircraft and the basic problem, in my opinion was that it was an aircraft with so many new innovations, a procurement apparatus at war with the company, and fluctuating and listless interest in the whole project by the Luftwaffe hierarchy. Its problems, in other words were very deep seated and not just the result of technical over reach

Thanks for the input guys.

 

[SpicyJuan11]

Its partly just plane bad luck. Lets look at the Manchester/Lancaster

The Manchester was introduced into RAF service in November 1940. It was overweight and therefor underpowered. There was no hope of strengthening the Vulture engines bearings in a reasonable time so 4 separate Merlin engines inside of Beufighter power eggs were installed on a modified wing. The Lancaster thus entered service in February 1942.

Hence the British took 15 months to recognise and fix the Manchester/Lancaster problem.

The He 177 entered service as the He 177A1 in mid 1942 to late 1942 about 18 months after the Manchester. It has experienced delays for structural reasons as well as engine issues. It was a more ambitious and advanced design than the Lancaster/Manchester in regards to range and speed.

Had the problems with the engines been regarded as insurmountable and 4 separate engines fitted from that point on a 15 month period would imply a 4 engine He 177B could be available in late 1943. It seems the fix was always just around the corner. With pilot training, good maintenance maritime patrol He 177 achieved acceptable engine MTBO of 220 hours by March 1944.

The Luftwaffe just didn't have enough time to recognise the problem and alter the aircraft because it had been delayed till mid 1942. If the 'disaster'had of happened earlier the drastic action might have been taken.

Its issues needed to be recognised during testing as insurmountable and radical action taken in Mid 1941 or so irrespective of cost.

What if the issues were seen early on, and the RLM decided to take up Heinkel's counter-proposal the He 177B in 1939? Could it have been in service earlier, how would it perform?

 

[Shortround6]

If you want in service sooner you have to figure the state of the art at the time. Figure the lower powered engines, a bit more drag, defensive armament that, shall we say, is lacking. Part of the problem was the ever changing specifications. The V1 having a crew of 3 men and 3 defensive MGs. one in the tail, one above the fuselage behind the flight deck and one in the ventral gondola. The man responsible for the lower and upper guns must have been fairly athletic.

A 4th man was added on the V2 in the picture. The prototypes may not have carried full armament. The above list of weapons for the V-1 were, in fact, not fitted.

performance was waaay less than expected with the V1 making 286mph and the V-5 and V6 supposedly doing 289mph max cruise and 263mph long range cruise with production "standard" engines. Service ceiling was reported as just under 23,000ft.

It was Aug 2 1941 when the V6 and V7 Show up on the French coast for operational evaluation. Timing is slipping away. The A-0 and A-1 have five men and a rather amazing collection of defensive guns. 6 guns total of 3 different calibers. Three 7.92s, two 13mm guns and a single 20mm MG FF out the front of the gondola.
Compare this to the B-17E which first flew on Sept 5th, 1941 and 42 were delivered by Nov 30th 1941. "one 0.30-inch machine gun which could be mounted on any one of six ball-and-socket mounts in the extreme nose. One Sperry No. 645473E power turret in the dorsal position with two 0.50 Browning M2 machine guns with 500 rounds per gun. One Sperry No. 654849-J power turret in ventral position with two 0.50-inch Browning machine guns with 500 rounds per gun. One 0.50-inch Browning M2 machine gun is each of the two waist windows, 400 rounds per gun. Two 0.50-inch M2 Browning machine guns in the tail position, with 500 rounds per gun."

From Joe Baughers web site. I would note that the B-17E was supposed to be able to hit 318mph at 25,000ft although cruising speeds were much lower. The B-17E was incapable of defending itself over Europe with eight .50 cal guns and 4 of themin power turrets. Chances of the He 177 with either 2 props or 4 being able to operate in daylight in areas with enemy fighters without strong fighter escort are about zero.

 

[SpicyJuan11]

If you want in service sooner you have to figure the state of the art at the time. Figure the lower powered engines, a bit more drag, defensive armament that, shall we say, is lacking. Part of the problem was the ever changing specifications. The V1 having a crew of 3 men and 3 defensive MGs. one in the tail, one above the fuselage behind the flight deck and one in the ventral gondola. The man responsible for the lower and upper guns must have been fairly athletic.

View attachment 295073

A 4th man was added on the V2 in the picture. The prototypes may not have carried full armament. The above list of weapons for the V-1 were, in fact, not fitted.

performance was waaay less than expected with the V1 making 286mph and the V-5 and V6 supposedly doing 289mph max cruise and 263mph long range cruise with production "standard" engines. Service ceiling was reported as just under 23,000ft.

It was Aug 2 1941 when the V6 and V7 Show up on the French coast for operational evaluation. Timing is slipping away. The A-0 and A-1 have five men and a rather amazing collection of defensive guns. 6 guns total of 3 different calibers. Three 7.92s, two 13mm guns and a single 20mm MG FF out the front of the gondola.
Compare this to the B-17E which first flew on Sept 5th, 1941 and 42 were delivered by Nov 30th 1941. "one 0.30-inch machine gun which could be mounted on any one of six ball-and-socket mounts in the extreme nose. One Sperry No. 645473E power turret in the dorsal position with two 0.50 Browning M2 machine guns with 500 rounds per gun. One Sperry No. 654849-J power turret in ventral position with two 0.50-inch Browning machine guns with 500 rounds per gun. One 0.50-inch Browning M2 machine gun is each of the two waist windows, 400 rounds per gun. Two 0.50-inch M2 Browning machine guns in the tail position, with 500 rounds per gun."

From Joe Baughers web site. I would note that the B-17E was supposed to be able to hit 318mph at 25,000ft although cruising speeds were much lower. The B-17E was incapable of defending itself over Europe with eight .50 cal guns and 4 of themin power turrets. Chances of the He 177 with either 2 props or 4 being able to operate in daylight in areas with enemy fighters without strong fighter escort are about zero.

Well yes, I was thinking that the best place for them would be on the eastern front where the Soviets air defense in 1941-1942 was also a bit lacking.

 

[SpicyJuan11]

If you want in service sooner you have to figure the state of the art at the time. Figure the lower powered engines, a bit more drag, defensive armament that, shall we say, is lacking. Part of the problem was the ever changing specifications. The V1 having a crew of 3 men and 3 defensive MGs. one in the tail, one above the fuselage behind the flight deck and one in the ventral gondola. The man responsible for the lower and upper guns must have been fairly athletic.

View attachment 295073

A 4th man was added on the V2 in the picture. The prototypes may not have carried full armament. The above list of weapons for the V-1 were, in fact, not fitted.

performance was waaay less than expected with the V1 making 286mph and the V-5 and V6 supposedly doing 289mph max cruise and 263mph long range cruise with production "standard" engines. Service ceiling was reported as just under 23,000ft.

It was Aug 2 1941 when the V6 and V7 Show up on the French coast for operational evaluation. Timing is slipping away. The A-0 and A-1 have five men and a rather amazing collection of defensive guns. 6 guns total of 3 different calibers. Three 7.92s, two 13mm guns and a single 20mm MG FF out the front of the gondola.
Compare this to the B-17E which first flew on Sept 5th, 1941 and 42 were delivered by Nov 30th 1941. "one 0.30-inch machine gun which could be mounted on any one of six ball-and-socket mounts in the extreme nose. One Sperry No. 645473E power turret in the dorsal position with two 0.50 Browning M2 machine guns with 500 rounds per gun. One Sperry No. 654849-J power turret in ventral position with two 0.50-inch Browning machine guns with 500 rounds per gun. One 0.50-inch Browning M2 machine gun is each of the two waist windows, 400 rounds per gun. Two 0.50-inch M2 Browning machine guns in the tail position, with 500 rounds per gun."

From Joe Baughers web site. I would note that the B-17E was supposed to be able to hit 318mph at 25,000ft although cruising speeds were much lower. The B-17E was incapable of defending itself over Europe with eight .50 cal guns and 4 of themin power turrets. Chances of the He 177 with either 2 props or 4 being able to operate in daylight in areas with enemy fighters without strong fighter escort are about zero.

Well yes, I was thinking that the best place for them would be on the eastern front where the Soviets air defense in 1941-1942 was also a bit lacking.

 

[GregP]

Hi Juan,

Yeah, I knew what you meant and was just poking a little fun.

I don't think the He 177 was EVER going to be a good airplane myself. I think the He 277 could easily have been. I like V-12's but don't think the Allison V-3420 was ever really going to be agreat engine either, for much the same reasons. In the case of the V-3420, it never did get into a mass production aircraft. In the case of the He 177, they tried and found exactly what I woluld have expected.

What the world back then needed was a good, oil-tight gasket and the world today still needs that. When we HAVE one, then a W engine might make some sense. Until then it's an oil fire waiting to happen.

Your experience with any engine will not be the experience of the perfrectlky-maintained and perfectly-flown airplane. It will largely be the experience of the aircraft with average maintenance and operation. And if an average mechanic and pilot can't get reliable engine and airframe operation, the plane will fail in its intended task.

 

[nuuumannn]

The Luftwaffe just didn't have enough time

I don't think time was the issue in this case, Koopernic, although I agree with your point; the Luftwaffe/Germans had little clearly defined need for the He 177 quite in the same way as the British had for the Manchester, Halifax etc. Also, with ever changing requirements, as Shortround pointed out, it was never going to be satisfactory.

Like I pointed out, the Halifax's gestation into a suitable aircraft took the same length of time and while each subsequent model was a minor improvement, until Merlins were replaced with Hercules' its aerodynamic issues were not going to be cured - the engine was mounted in the wrong position on the wing, which increased drag and also lined the exhausts up with the wing leading edge, which resulted in large trumpet exhausts; the shielding for night ops produced enormous amounts of drag. Interestingly, the Lancaster Mk.II fitted with Hercs had a similar result of higher drag because of the engine mounting location; the Merlin on the Lancaster being mounted lower on the Lanc than the Hali. The Halifax IV was to be powered by Merlin 60s and the engines repositioned on the wing; after experiments done by Rolls Royce, the Halifax IV proved to have excellent performance and would have been a superior aircraft to the Lancaster III, but only one was built and the interim Hali III became the largest produced variant... anyway, I digress. Sorry folks.

A bit like the He 177 though, what if they had done this sooner etc...