B-17 vs. He-177 vs. Lancaster

[delcyros]

I unfortunately have no scanner here but here are some stats for the He-177A5 (Nowarra, Vol.2, p.230f.):
max. fuel: 12.400l. (overloaded)
long range fuel: 9.610l
middle range fuel: 7.610l
short range fuel: 5.610l (=max. bombload: 7.2t.)
-from these number it should be possible to verify the range with the DB-610A/B fuel consumption figures-

payloads: max: 7.2t.
normalinternal: 48 x 70Kg, or 10 x 500Kg, or 6 x 1000Kg or 2 x 2500Kg
external hardpoints for 3 x Hs 293/4 or 3 x PC 1400FX or torpedoes

Ferry range is specified with 5.600Km.
The range is given with 3.700 Km, payload not specified.
Cruise speed is given with 510 Km/h, payload not specified.
top speed is given with 540 Km/h, payload not specified.

The 3.700Km range is from my understanding the range with normal payload (5t.), short range would be ~2.500-2.800Km at 7.2t. payload and long range would be 4.200-4.400Km at 3t.? perhaps someone could verify this with He-177 Werksausgabe, Bed.-Vorschrift, 1943,
Operating instruction, flight manual. D(Luft)T2177A5?

 

[Kurfürst]

I unfortunately have no scanner here but here are some stats for the He-177A5 (Nowarra, Vol.2, p.230f.):

...
The range is given with 3.700 Km, payload not specified.
Cruise speed is given with 510 Km/h, payload not specified.
top speed is given with 540 Km/h, payload not specified.

Interesting. I did some calculations to figure out what engine rating the 510 and 540 figures refer to. The difference is 5,88 %. Power requirements increase on the cube, so to get 510 -> 540 km/h, you will need appx. 18.7% power.

Assuming 'cruise' means maximum continous cruise settings (Höchtz. Dauerl.), this would mean 1080 PS at rated altitude, increasing this by 18.7% yields 1282 PS (and there`s some inaccuracy with these rough calculations).

The 30-min rating was 1250 PS (stating) at altitude.

It would seem thus the 540 km/h figure is understood for 30-min Military power, or 100% Steig und Kampfleistung in German terms. Given that, the 565 km/h figure seems reasonable at 110%, 5-min WEP rating or Startleistung.

It should be noted though that with a plane of such size, the top speed would be more sensitive the loading than with fighters.

In any, 510 km/h for cruise is massively impressive for a bomber of this size. The Mosquito FB VI, for example, was measured at 544 for cruise.

 

[JoeB]

In fact, and as i seem to recall, loss rate for the B-29 is worse: a total of ~1,950 ships delivered losing ~650 from all causes...consider timeframes for B-29 operations in the PTO and the result ain´t very flattering: first bombing runs were flown from India and China (June 1944); first combat missions flown in the Pacific did not occur until late 1944 (October) involving B-29s based in the Marianas...during said period of time the Japanese aerial forces of the time were in real poor shape, nowhere near close to the type of fighter opposition faced by the 8th and 15th AFs in the ETO during the same time. Of the approximate ~650 B-29´s lost in operations, something around ~120 were due to enemy action, less than 25% of the total losses....

I think your general point is reasonable, but I'd question the numbers somewhat on B-29's. The USAAF Statistics Digest gives 414 B-29's lost on combat missions (how I would interpret 'on operations') of which 147 were specifically attributed to enemy action. (that represented a 1.3% per sortie loss rate for the total; and it includes both China and Marianas operations; 8th/15th sortie loss rate was 1.6%). Maybe your total includes training including in the US? Also, some B-29 losses to 'other cause on combat mission' might be planes damaged over Japan by enemy action. On a tangent, it's often said that that's true of B-29 loss accounting in Korea but tracking down each one I found it was rarely true, the official combat loss number was approximately correct in that war, but I've seen several examples in WWII where damaged planes that couldn't make it back all the way to the Mariana's were counted as 'other'. The % might be higher than in Korea also, though I'm not sure how high. At some point somebody may go through all the WWII B-29 losses from original records and reclassify their causes (or maybe somebody has, but not that I know of); AFAIK the details still exist.

Also turning your point around about opposition, lack of consisently highly tough opposition is one reason the proportion of operational losses was higher for the B-29; the more difficult operational conditions, distance particularly, were another. Also, the opposition varied a lot, was not consistently weak. The intial campaign from the Marianas v Japan Nov '44-Feb '45 was unescorted in daylight, with no 'milk runs' available v targets in occupied Europe like the 8th could do when it needed a break from its attempt at unescorted raids over Germany ca. 1943. And the Japanese rammed extensively, see Henry Sakaida's "B-29 Hunters of the JAAF" for two-sided treatment; that accounted for most of the B-29's downed by hostile action in that initial phase, and was quite a difficult tactic the 8th and 15th seldom had to deal with. Later on opposition waned, both in the night raids from March 1945 for which Japan was less prepared and when daylight ops resumed alongside night from April to the end of the war.

But I agree with you, the B-29 in its early WWII operation mid 1944- early 45 was a pretty buggy airplane, I don't think anyone familiar with its history would contest that as general statement. And not all those bugs were ever competely ironed out; it still suffered a somewhat elevated operational loss rate even in Korea, though much lower by then, and lower even as 1945 went on.

Joe

 

[delcyros]

The official post war Very heavy bomber investigation (only B-29) give the following numbers:

Losses B-29 during it´s ww2 career:
in combat:
to enemy action (confirmed): 148
to operational factors: 151
to unknown causes: 115 (some been rammed)
to training accidents / ferry flights on theatre of action: 97
written off / canibalized due to damage received in action: 286
in the US:
to training accidents: 260

total on theatre of action: 809
total during ww2: 1069

production B-29:
B-29: 2513=
Boing -Wichita: 1620, producing the last B-29 in oct. 45.
Martin-Omaha: 536
Bell Marietta: 357
B-29A: 1119, the last beeing produced ?
B-29B: 339, the last been produced ?
total: 3.971 (including production after VJ-day)

This is about 1/3 to 1/4 of all B-29 produced in ww2 beeing lost or written off. All training accidents ca. 33%, operational losses ca. 39% (all causes) and written off due to damage received ca. 27%.

 

[model299]

I realize that overall, the Lanc is probably the superior plane technically, but my screen name and a look at my avatar will tell you which plane got my vote.

 

[Juha]

Hello Delcyros
a bit strange that Novarra gives exactly 100km/h greater max speed than that given in Griehl's and Dressel's book or in matter of fact in Brown's book. From G's D's book is clearly seen that they have went through a lot of original technical documents on He 177. In my copy of Brown's book I have noted on mariginal that on p. 207 of Roderich Cescotti's Kampfflugzeuge and Aufklärer in Die Deutsche Luftfahrt series, which I have understood is rather authorative book, gives the same specs than those in Brown's book but some ammo figures plus some extra info, propeller diameter etc. Now I cannot recall exactly what the He 177 pages looked in Cescotti's book but I recall that in Do 17 part he had reproduced pages from original pilot's notes and speed graps because some of them were the same that can be found from Finnish Air Force papers. What's your opinion on Cescotti's book?

Juha

 

[Udet]

I think your general point is reasonable, but I'd question the numbers somewhat on B-29's. The USAAF Statistics Digest gives 414 B-29's lost on combat missions (how I would interpret 'on operations') of which 147 were specifically attributed to enemy action. (that represented a 1.3% per sortie loss rate for the total; and it includes both China and Marianas operations; 8th/15th sortie loss rate was 1.6%). Maybe your total includes training including in the US? Also, some B-29 losses to 'other cause on combat mission' might be planes damaged over Japan by enemy action. On a tangent, it's often said that that's true of B-29 loss accounting in Korea but tracking down each one I found it was rarely true, the official combat loss number was approximately correct in that war, but I've seen several examples in WWII where damaged planes that couldn't make it back all the way to the Mariana's were counted as 'other'. The % might be higher than in Korea also, though I'm not sure how high. At some point somebody may go through all the WWII B-29 losses from original records and reclassify their causes (or maybe somebody has, but not that I know of); AFAIK the details still exist.

Also turning your point around about opposition, lack of consisently highly tough opposition is one reason the proportion of operational losses was higher for the B-29; the more difficult operational conditions, distance particularly, were another. Also, the opposition varied a lot, was not consistently weak. The intial campaign from the Marianas v Japan Nov '44-Feb '45 was unescorted in daylight, with no 'milk runs' available v targets in occupied Europe like the 8th could do when it needed a break from its attempt at unescorted raids over Germany ca. 1943. And the Japanese rammed extensively, see Henry Sakaida's "B-29 Hunters of the JAAF" for two-sided treatment; that accounted for most of the B-29's downed by hostile action in that initial phase, and was quite a difficult tactic the 8th and 15th seldom had to deal with. Later on opposition waned, both in the night raids from March 1945 for which Japan was less prepared and when daylight ops resumed alongside night from April to the end of the war.

But I agree with you, the B-29 in its early WWII operation mid 1944- early 45 was a pretty buggy airplane, I don't think anyone familiar with its history would contest that as general statement. And not all those bugs were ever competely ironed out; it still suffered a somewhat elevated operational loss rate even in Korea, though much lower by then, and lower even as 1945 went on.

Joe

Joe, hello.

I did the numbers from memory. I am sure more than 2,000 B-29s were produced during the war -around 2500- but no more than that (2,000) were sent into combat operations in the PTO.

One person told me once that nearly 4,000 B-29s were built during WW2, but i did not believe the figure; after further asking i was confirmed the 4,000 airplane figure was for the entire B-29 production era, which of course includes post WW2 versions of the B-29 that were produced.

Now, the ~650 B-29s lost from all causes during WW2 did not include training losses that ocurred in the U.S.A.

Now according to numbers posted by Herr Delcyros here total losses are somewhat higher, quote:

Losses B-29 during it´s ww2 career:
in combat:
to enemy action (confirmed): 148
to operational factors: 151
to unknown causes: 115 (some been rammed)
to training accidents / ferry flights on theatre of action: 97
written off / canibalized due to damage received in action: 286

Total: 798 B-29´s lost

It´d be interesting to know what should we understand by "operational factors" though; losses from engine or other technical problems (bugs) perhaps?

As for those lost in training flights in the U.S.A. i was familiar with the figure of ~260 ships lost, consistent with the number on Herr Delcyros´ posting.

This should be critical in comprehending how buggy and complex the aircraft was in reality: ~260 planes lost in training flights in the U.S.A. would account for nearly 10% of the approximate total number of B-29s produced during WW2...not what you´d call a low figure eh?

So the poor He 177, which was pressed into service during a time when it was not really required, and in limited numbers only -also belonging into the defeated "evil" side- gets all the rotten eggs and tomatoes thrown at. This is bizarre, the Germans seemed to have finally fixed all bugs on the He 177, while U.S. engineers seemed uncapable of solving their own for the most part of the operational history of the B-29 during WW2.

I was of course referring to loss % examined against total number of B-29s deployed in operations; yes, it is only one approach, but it is exactly the same thing done by the Allied boys when referring to the Steinbock raids of the Luftwaffe against Great Britain in the first 5 months of 1944, when a bomber force of ~550 planes was assembled and launched against England. They say that by the end of May, 1944 that from the initial number (~550) only a few bombers remained, thus the "catastrophic" nature of the Steinbock raids.

We seem to agree here Joe, the B-29 was not a less buggy plane than the He 177, but for some "odd" reason such details are oftenly overlooked in the case of the B-29 focusing mainly on his battle exploits (ie. incinerating Japan´s paper and wood housing and cities, slamming their industry, the atomic bomb, etc.); we can not say the same about the He 177...search the internet for "He 177" and you will find loads of crappy webpages focused mostly -and mainly- on those "troublesome engines catching fire"; someone first came across such data, put it on a webpage, then like a virus spreading across the land, many others simply copied the same data without bothering to read or research further and put it on several other webpages. Selective use and manipulation of information that is, tainted with the vision of the victors.

As for operational conditions i agree: the B-29´s flying from the Marianas had to fly across a vast extension of ocean but the He 177s too had to operate in the open sea, and they did it in the majority of missions flown, mainly in KG 40 and KG 100; acknowledged is the fact distances covered by He 177s of KG 40 and KG 100 over the sea were not of the dimension observed in the PTO, but its still open sea and the plane performed very well in that scenario losing only a few from technical problems.

Finally Joe, i came along with this to state my view that ~30% of B-29s deployed against Japan were lost from all causes. Overall that´s certainly high. Understood are your arguments of operational conditions and enemy oppossition (fighter force and AA defence), but i believe you will agree with me that by the time the B-29 commenced flying from the Marianas (late 1994) the Japanese were horribly mauled and their home defence systems were way behind those of Germany; if the enemy they confronted was not strong enough to threaten B-29 formations, perhaps the B-29 itself was its own most dangerous enemy; they were lucky the Japanese proved uncapable of organizing and developing a more effective fighter/AA system.

Also do you have any numbers of B-29 losses over Japan during the time they flew unescorted...i do not, but i am confident to affirm that any B-17 or B-24 pilot that flew over the Reich prior to the arrival of long rage escorts (P-51s) in 1943 and early 1944 would have found flying unescorted bomber missions over Japan the most joyous of the rides.

Had the B-29 then faced the type of Flak defence systems and fighter strength similar to that of the Germans, then it is not daring to assume their losses could of been quite higher.

 

[syscom3]

3895 B29's were built between July 1943 and Sept 1945. Only 9 B29's were built in Oct, Nov and Dec 1945.

 

[FLYBOYJ]

Again interesting points Udet but a few things to consider....

The B-29 was a weapons' system that HAD to work - the US was depending on its success and even though there were bugs that were never worked out they were accepted as "collateral flaws" something I think every aircraft has. As far as the 177 - a promising airframe that had a lot stacked against it. First off you had the Luftwaffle not embracing the four engine strategic bomber concept. I don't believe the He-177 never had the strategic importance behind it. Combine that with limited strategic resources and the "dive bombing" requirement and you have set a recipe for failure - and maybe not the fault of the initial design.

As far as the losses of the B-29 - you had a "state of the art aircraft" being rushed into production and deployment during a wartime urgency and flown by kids. Considering those factors I'm surprised the losses weren't more. As far as those "unknown" losses - I doubt the majority of those could really be attributed to Japanese interceptions and "rammings." I don't know what kind of numbers JoeB could come up with from the Japanese camp but I would have a hard time believing that they were a majority of that 115.

It's hard to say how the 177 would of played out and allowed to mature and then subjected to the same production numbers and urgency the B-29 went through. I still believe the B-29 was technically superior but the 177 wasn't that far behind. Also consider those post war training accidents that occurred during the formation of SAC - little risk mitigation, LeMay wanted results and nothing more - I think there were a lot of unnecessary risks that resulted in the loss of many men and aircraft.

Written off aircraft that made it back to their base - I don't consider them losses in the sense of being lost to fighters or flack. If the crew makes it back with the "asset" and that asset can be utilized to keep other assets flying - then it has served a purpose - it relieved part of the "supply chain."

 

[drgondog]

In this type of threads there will always be this sort of automatic tendency to consider the Allied hardware the best.

All too true

I am sure the He 177 was a very fine craft with lots of potential -and not necessarily more technical problems than the B-29- but saw service in limited numbers and did not have any chance for making any measurable contribution in favor of Germany´s war effort.

Also true

I have studied operations of KG 40 and KG 100 in the past -two units that used the He 177 in operations- and their loss ratio seemed anything but "catastrophic". In fact, and as i seem to recall, loss rate for the B-29 is worse: a total of ~1,950 ships delivered losing ~650 from all causes...consider timeframes for B-29 operations in the PTO and the result ain´t very flattering: first bombing runs were flown from India and China (June 1944); first combat missions flown in the Pacific did not occur until late 1944 (October) involving B-29s based in the Marianas...during said period of time the Japanese aerial forces of the time were in real poor shape, nowhere near close to the type of fighter opposition faced by the 8th and 15th AFs in the ETO during the same time. Of the approximate ~650 B-29´s lost in operations, something around ~120 were due to enemy action, less than 25% of the total losses...this leaves a 75% of losses due to causes other than enemy actions: accidents, technical problems...could this lead us to assume the B-29 was not as good as portrayed?

Udet - there is nothing like a 1,500 mile return trip to surface mechanical problems, 200 mph headwinds, ets.

Correct me if necessary but while i could not mention details on the matter, there were some technical problems on the B-29 that were never solved during the time the model saw combat operations.

the 3350 was a dear! nothing like engine fires with 1500 miles of blue water to set your mind thinkin'

As a very young kid coming back from Japan in Nov 1950 we flew back in the KC 97 and I had the joy of watching #3 trail 50 foot flames before the pilot put them out in a dive. After two of these including an emergency landing at Johnson Is, my mother booked a Dutch freigter rather than do that again

If you consider the fact a large number of the He 177s deployed in operations flew their missions over the sea it would then be reasonable to assume the He 177 was a reliable plane, reliable enough to allow for such type of missions -this to counter the other classical tale of "never ending engine problems that plagued the bomber"-.

I think the major issue with all these comparisons, as you have put out before is that aren't comparable mission profiles.. how many want to fly a He 177 from Guam to Tokyo and bomb from 28,000 feet in a headwind of 200mph? with a 9,000 pound bomb load?

I'm glad I didn't fly either one at the edge of their performance profiles.

Tip of the hat A,

Bill

PS we had snow on New years and the wolfhounds were hysterical dashing about like kids!

 

[syscom3]

Also consider the airframe itself. Was their room for growth? The B29 added a crew member with specialized eqmt (radar and ECM) AFTER the design had been frozen and it was in production. Could the German design do that? It looked awfully cramped in there. Hardly any room to add all new weapons systems and additional aircrew.

What about the bomb bay? Could it handle oversize bomb loads without airframe modifications? The B29 could handle internal stowage of any bomb the allies had, save two.... the Grand slam and A-Bomb.

 

[delcyros]

Hello Delcyros
a bit strange that Novarra gives exactly 100km/h greater max speed than that given in Griehl's and Dressel's book or in matter of fact in Brown's book. From G's D's book is clearly seen that they have went through a lot of original technical documents on He 177. In my copy of Brown's book I have noted on mariginal that on p. 207 of Roderich Cescotti's Kampfflugzeuge and Aufklärer in Die Deutsche Luftfahrt series, which I have understood is rather authorative book, gives the same specs than those in Brown's book but some ammo figures plus some extra info, propeller diameter etc. Now I cannot recall exactly what the He 177 pages looked in Cescotti's book but I recall that in Do 17 part he had reproduced pages from original pilot's notes and speed graps because some of them were the same that can be found from Finnish Air Force papers. What's your opinion on Cescotti's book?

Juha

Hi Juha,

I don´t think the numbers necessarely contradict each other. That´s because the payload isn´t specified but has a huge impact on top speed. The He-177 tested in England was reported to have a top speed of 483 Km/h at something like 80% gross weight at slightly different altitude. I could imagine that the Nowarra figure belongs to top speed in it´s original sense (i.e. without payload, as none is specified-he specified the load on other bombers), while other figures belong to loaded conditions. This would be in within typical margins of other bombers. However, as I pointed out above, the flight instruction manual, which I haven´t seen so far, contains the information You want to get.

best regards,
delc

 

[Juha]

Thanks Delcyros
I'm still a bit sceptical. IMHO the weight itself should not have very big influence on speed, but of course I might be wrong. 177A-3 usually carried its bombs internally, IIRC only 2*SC2500 load was carried externally, so dropping the bombs should not have very big effect on speed. But not being expert on this I can be in error. I'm very busy now so I don't have time to check but IIRC max speed of Do17Z-2 at max load was 425km/h and 433km/h at 75% load according to German tests. So the speed difference wasn't big. It was different thing with a/c carrying most of their load externally, again IIRC Ju88A-4 max speed at max weight was 435km/h but after dropping its bombs its max speed was 475km/h.

Best Regards
Juha

 

[FLYBOYJ]

Also consider the airframe itself. Was their room for growth? The B29 added a crew member with specialized eqmt (radar and ECM) AFTER the design had been frozen and it was in production. Could the German design do that? It looked awfully cramped in there. Hardly any room to add all new weapons systems and additional aircrew.

What about the bomb bay? Could it handle oversize bomb loads without airframe modifications? The B29 could handle internal stowage of any bomb the allies had, save two.... the Grand slam and A-Bomb.

good points...

 

[delcyros]

Thanks Delcyros
I'm still a bit sceptical. IMHO the weight itself should not have very big influence on speed, but of course I might be wrong. 177A-3 usually carried its bombs internally, IIRC only 2*SC2500 load was carried externally, so dropping the bombs should not have very big effect on speed. But not being expert on this I can be in error. I'm very busy now so I don't have time to check but IIRC max speed of Do17Z-2 at max load was 425km/h and 433km/h at 75% load according to German tests. So the speed difference wasn't big. It was different thing with a/c carrying most of their load externally, again IIRC Ju88A-4 max speed at max weight was 435km/h but after dropping its bombs its max speed was 475km/h.

Best Regards
Juha

You are welcome. I don´t want to convince anybody, just proposing what I have read. Everybody is free to draw his own conclusions, of course.
Adding 7t. of weight will have notable effects on performance. More if aerodynamic drag is induced by external loads. However, not weight per see reduces performances but cog-shift and, more important, the amount of power necessary to achieve a cruise speed / cruise altitude profile. This can be seen on the B-29 charts provided by HoHun.
A further notable difference is that the powersetting is not known for the top speed figures. I doubt that the DB-610 was ever cleared for 110% WEP, it was to troublesome (I might be wrong here), and it isn´t impossible that early engines possibly might have been limited even further artificially. I haven´t the necessary knowledge on this matter. A thoroughly made study of the engine and primary sources of the He-177 would be highly welcome to clear this. Perhaps someone can obtain a copy from the instruction manuals of the He-177 from the Luftarchiv Hafner.

 

[HoHun]

Hi Juha,

>I'm still a bit sceptical. IMHO the weight itself should not have very big influence on speed, but of course I might be wrong.

The size of the influence strongly depends on the altitude as well as on the relative load difference.

I just made a quick calculation based on a top speed of 520 km/h @ 5.7 km for a 31 t Heinkel He 177A-5/R2 using 1.3 ata/2600 rpm - these figures are from Heinkel datasheets, reprinted in the datasheet collection "Heinkel" (Aviatik-Verlag, no author/editor attribution).

With no payload, 50% fuel, 50% oil, I get a weight of 23915 kg, which gives a top speed of 545 km/h @ 5.8 km at the same power settings as above. (Ram effect is responsible for the slight increase in best altitude.)

However, if we look at altitudes above full throttle height, the difference is even more striking - at 31 t, the He 177 does 440 km/h @ 8 km according to my calculation, but at 23915 kg the possible top speed increases to 510 km/h at this height.

The reason for this large difference is that the large coefficients of lift necessary for flight at high altitude and heavy weights translate into very high induced drag, and getting rid of this weight increases the available excess power considerably.

If you ever wondered why high-altitude aircraft tend to have large wings - this is it

(From the perspective of performance analysis, the large influence of flying weight makes it very difficult to come up with accurate figures as there are few good sources that give the complete data required for an accurate analysis. So take my speeds for the He 177 as illustrations for the principle only, I don't really have enough data on the type to make any bullet-proof statements.)

Regards,

Henning (HoHun)

 

[Udet]

Syscom...can you confirm the figure for B-29s produced during ww2?

 

[syscom3]

Syscom...can you confirm the figure for B-29s produced during ww2?

The figure is very accurate. Its from my B29 production book thats a trove of information. production essentially ended in Sept 1945. I beleive the AAF was already comtemplating production of the B-50 and saw no reason to build the B-29 as it was.

 

[Juha]

Thanks a lot Delcyros and HoHun
your answers made things clearier. I had wondered why they gave 80% of max weight performance but after reading HoHun's message I saw the light.

I had time to take a brief look on Do17Z and my memory had made one trick, the 433km/h speed wasn't for 75% load but for 7400kg which is nearer to 85% of max weight. And I admit that Do17Z was a bit different a/c than He177A.

Thankfully
Juha

 

[albion]

Best ww 1 bomber Vickers Vimy.First plane to fly non stop across the Atlantic.