As a preface to the topic I'd like to say hello. Just a thirty something aviation enthusiast joining your ranks from Sweden. Hello!

My interest in aviation is broad. After reading the excellent "Speedbird - The complete history of BOAC" by Robin Higham I became very curious about passenger converted bombers. It's obvious that early post-war Britain (airlines across the globe really) scrambled to fill civilian needs with bomber conversions. While plenty know of the Avro York, this aircraft mated a new fuselage to the wings of a Avro Lancaster, making it more of a new plane than a conversion.

Below are a few examples. I'd love to know more about how they were perceived by passengers and crew and what they looked like outside and in. In most cases pictures and stories are incredibly hard to come by. These planes were not seen as glamorous and served a stop-gaps. Therefore information is scarce; nothing more than slightly expanded footnotes.

BOAC Lancastrian
The BOAC Lancastrians were given rounded noses and converted the bomb bay into passenger accommodations. The slim fuselage posed challenges though, and the high fuel consumption made them incredibly uneconomical. They were used by BOAC and QANTAS for express services post-war until purpose built aircraft could be sourced. Plenty of other airlines used them as well, both for passengers and cargo.

Pictures below courtesy of https://travelupdate.com/sideways-seating-avro-lancastrian/. The article is well worth the read.

Outside


Interior of BOAC - Interesting sideways seating


Interior of BSAA - Slightly more conventional



Handley Page Halton
The Handley Page Halton is a slightly more shy beast. It never got quite the sales I'm assuming. I have precious little info about her and I'm very curious. So if you fine folks have more info I'd be delighted to hear it. It seems as though there was more space in the passenger cabin than the Lancastrian. Commonly a pannier was also added to the bottom of the fuselage. The purpose of which is unknown to me, possibly freight? Again, if you know more about her interiors and/or service and what passengers and crew thought about her it would be very valuable to me.

Exterior picture courtesy of Wikipedia


I have no interiors, but this cut-away courtesy of http://www.aviationancestry.co.uk shows it to be an interesting layout.


Consolidated C-87
The passenger liberator was, according to wikipedia, not a terribly pleasant aircraft for crew to fly. With many vices. Interiors that I've come across have also been incredibly sparse, with naked metal interiors and toilets with a "privacy curtain" in lieu of a proper door for a lot of them. BOAC had at least one in service, and I've got to wonder if the intriors of this example weren't better. Looking at the Lancastrian there seems to have been actual effort put into making it as nice as possible. I would love to see their Liberator interior. As a side note: I do love the fact that the faired nose looks a bit like a sperm whale or moomin (if you're familiar with the Finnish children's figures).

Exterior view courtesy of wikimedia


I've sourced the following picture from Reddit, there is no attribution as to actual source I'm afraid.


Boeing B-17 conversions
Boeing did have both an "official" conversion called the C-108, as well as other conversions. This might be the beast I know the least about that carried passengers. Boeing has an interesting article on their own Boeing Frontiers magazine about the Scandinavian examples which you can read more about here: https://www.boeing.com/news/frontiers/archive/2006/february/i_history.html

A picture from the same article


Discussion
There were other conversions, some I simply don't know about (so please do chip in), and others were converted for freight. And as interesting as freight handling is, I'm personally more interested in the trickier passenger conversions.

In a few cases I wonder why the likes of BOAC didn't adopt more conversions at the very end of the war years. The York is the only real effort to make a quick and easy "proper" airliner out of a bomber. There were also plenty of conversions of flying boat Short Sunderlands, and these airframes were eminently suitable and easy to convert. But it seems as though both the Halfords and the Liberators could have been lengthened and pressed into service for short to medium haul routes as well, though it would have required more effort.

Of course, the DC-3, DC-4, and Constellations were purpose built and better suited. But especially Britain suffered heavily from a debt burden. They didn't want to spend dollars which were necessary for other national interests. The economy working differently then than it does now means that dollar reserves were exceptionally valuable in a way that they aren't today in the same way. Which should have made how grown conversions economically viable propositions.

If BOAC would have accepted them is a different matter. BOAC had to compete with American and European airlines and had a sense, true or not, that bomber conversions would be donkeys racing stallions. And the storied Brabazon committee made no recommendations for bomber derived stop-gaps. Instead focusing wholly on new ventures in order to let British aircraft manufacturers catch up technologically. The Hadley Page Hastings military transport derived Hermes was the only one, and it was delayed far too much to be useful. Converting the unpressurised Hastings to a DC-4 competitor was too radical to be done in a timely manner as it turned out. I propose that had production of Yorks and lengthened/enlarged Haltons been done before wars end the need for the Hermes would never have arisen. Then again, had the Avro Tudor been persevered with the entire question would be moot. But what is the British aircraft industry but a huge list of depressing what-ifs?

What's evident is that they and others DID use bomber conversions. The stories of which are few but oh so tantalising. What was it like to fly on a SILA B-17? The Halford? A BSAA Lancastrian to South America? How were they used and why in airliner networks? It's simply a bit of a forgotten part of aviation history in my opinion. A small but important one.

Hello.
The current (June 2021) edition of 'Aeroplane' covers the development and use of the Lancastrian in detail. It is well worth reading if you can get hold of a copy.
After the war, BOAC didn't adopt more bomber based aircraft simply because the airline was expecting new designs like the Tudor and Hermes to quickly become available, with the Lancastrian to be a stop-gap only until those types were ready for service.
Before replacement types arrived, BOAC Lancastrians operated services to Australia and New Zealand and South America (there were route swaps with BSAA, and then BSAA was absorbed).
In 1946 the UK Government approved the use of precious dollars for a BOAC order for Constellations for use on the Atlantic.
In 1947, after a number of issues and delays, BOAC cancelled its order for Tudors and the airline never flew the type.
From 1949 on BOAC operated a fleet of Canadair Argonauts (the DC-4 with RR Merlin engines).
The Hermes entered service with BOAC in 1950.
By then (or thereabouts) the Constellation had developed into the more capable L749 version and DC-6 had appeared. The UK airliner industry had been left behind.

The Russians converted 2 Tu-95s into Tu-116s by installing 2 pressurized cabins for 20+ passengers, a wardrobe and a lavatory. It was a "plan B" aircraft in case the Tu-114 (itself derived from the Tu-95) wouldn't be ready in time for Krushchev's visit to the US in 1959.

QANTAS operated Consolidated Catalina PBY's on the famous double sunrise route across the Indian Ocean. There is a restored aircraft at the QANTAS Museum and a restaurant on Rose Bay in Sydney, one of the locations from which the Catalinas departed is named "Catalina" in remembrance of the aircraft.

Thank you Leovinus for an excellent posting. It looks like you've done a lot of research already. I like the way that you describe the British aircraft industry as a list of depressing "what-ifs". I think this is simply an extension of the British mentality. I would describe the British football and cricket teams using similar language. (Yes I am a Brit) M76

In addition to the Swedish examples, "Final Cut: The Post-War Boeing B-17 Flying Fortress" by Scott Thompson notes that a single B-17 was also civilianized by Boeing and TWA. Registrations were NX4600 and NL1B. No photos of the interior, and it may not have been used for scheduled service, but you might consider following up on this book if you're curious.

A-26 Invader converted to On Mark Marksman:

https://web.archive.org/web/20080620205559/http://www.airsceneuk.org.uk/hangar/2004/marksman/marksman.htm

Excellent topic, thank you!

Boeing Stratocruiser was a derivative, obviously (rather than a conversion) of Boeing B-29 bomber, though there's a body of opinion that it was a development of C-97 military transport (itself a version of B-29).

A slightly more convoluted story is of an interwar flying boat, Consolidated Commodore. It was a passenger plane, originally developed as US Navy's XPY-1 Admiral by Consolidated. US Navy selected the design, approved it, then turned around and gave the manufacturing contract to Glenn Martin. Consolidated went on to redevelop the design into passenger plane -- Consolidated Commodore. I tend to remember that the prototype (of XPY-1 Admiral) went on to become a Commodore, though cannot be sure on that detail.

In Jet Age, Tu-104 had the flying surfaces (more or less) directly transplanted from Tu-16 bomber. That gave some nasty aerodynamic issues to resulting passenger jet.

There was at least one case of reverse development happening -- Focke-Wulf Condor was originally designed to a commercial requirement (Lufthansa), and then was redeveloped into a military plane on Japanese request, eventually being adopted by Luftwaffe.

Newark727 wrote:

In addition to the Swedish examples, "Final Cut: The Post-War Boeing B-17 Flying Fortress" by Scott Thompson notes that a single B-17 was also civilianized by Boeing and TWA. Registrations were NX4600 and NL1B. No photos of the interior, and it may not have been used for scheduled service, but you might consider following up on this book if you're curious.

Sounds like it's precisely up my alley. I'll have to have a look and see if I can find it. Thank you kindly for the suggestion!

The Short Sunderland was a cool conversion.

I wish there was a "like" button to the comments in this thread.

A lot of aircraft have a heavy bomber heritage in their airframes as a lot of you point out. Especially Russian aircraft, but also mighty beasts like the Boeing B-377. In fact it's quite fun to see it all listed. Just shows you how much cross-over there was between military and civilian aircraft way back when. Some more overt than others, but all interesting.

For the this particular topic I'm personally more focused on the bombers airlines "slapped seats into", like the Lancastrian or Liberator Express and their ilk, than what came after them.

More interesting still is that this practice sort of ended after WW2. Lockheed had plans for civilian versions of both the Starlifter (which according to wikipedia was much more than paper proposals) and the C-5 Galaxy. Which sort of adhere to the "slap some seats into it" vibe. There were whispers of Antonov An-22's in passenger configurations, but this was more of a paper idea than real proposal so far as I know. The Canadair CL-44 might sort of count. Though it sort of fails as it was a military transport conversion based on the civilian Britannia, that got re-converted for civilian use by Icelandic airline Loftleiðir. So it sort of cheated by not being entirely military in origin.

I suppose the world had moved too far after WW2. Expectations were probably for more purpose built and thus more efficient aircraft than conversions could ever be, and there was no lack of good aircraft or funding to get them once economies recovered.

Newark727 wrote:

In addition to the Swedish examples, "Final Cut: The Post-War Boeing B-17 Flying Fortress" by Scott Thompson notes that a single B-17 was also civilianized by Boeing and TWA. Registrations were NX4600 and NL1B. No photos of the interior, and it may not have been used for scheduled service, but you might consider following up on this book if you're curious.

I believe it was only used for VIP transport. It was re-designated Model 299AB.

http://aviationtrivia.blogspot.com/2010/06/although-in-excess-of-25-different.html


From: https://www.dembrudders.com/uploads/1/2 ... m_orig.png


From:http://p8.storage.canalblog.com/86/80/871230/65687410.jpg

Many more photos here (post #28):

https://ww2aircraft.net/forum/threads/one-for-trebor.40045/page-2

Most Boeing narrowbodies have the fuselage of the 707, which shares a common ancestor with the KC-135. It wasn't converted, but the two families are pretty close.

starrion wrote:

Most Boeing narrowbodies have the fuselage of the 707, which shares a common ancestor with the KC-135. It wasn't converted, but the two families are pretty close.

The KC135 fuselage is narrower than the 707, and can only fit 5 abreast instead of 6.

Leovinus wrote:

I wish there was a "like" button to the comments in this thread.

A lot of aircraft have a heavy bomber heritage in their airframes as a lot of you point out. Especially Russian aircraft, but also mighty beasts like the Boeing B-377. In fact it's quite fun to see it all listed. Just shows you how much cross-over there was between military and civilian aircraft way back when. Some more overt than others, but all interesting.

For the this particular topic I'm personally more focused on the bombers airlines "slapped seats into", like the Lancastrian or Liberator Express and their ilk, than what came after them.

More interesting still is that this practice sort of ended after WW2. Lockheed had plans for civilian versions of both the Starlifter (which according to wikipedia was much more than paper proposals) and the C-5 Galaxy. Which sort of adhere to the "slap some seats into it" vibe. There were whispers of Antonov An-22's in passenger configurations, but this was more of a paper idea than real proposal so far as I know. The Canadair CL-44 might sort of count. Though it sort of fails as it was a military transport conversion based on the civilian Britannia, that got re-converted for civilian use by Icelandic airline Loftleiðir. So it sort of cheated by not being entirely military in origin.

I suppose the world had moved too far after WW2. Expectations were probably for more purpose built and thus more efficient aircraft than conversions could ever be, and there was no lack of good aircraft or funding to get them once economies recovered.

No idea on An-22 options, but it's actually open knowledge that Antonov An-10 and An-12 were a parallel design. There was even a conversion kit presumably developed, to fit An-10 with a ramp (one-way ticket, though, impossible to convert back into pax configuration). As a result, cockpit is basically separately pressurized on both An-10 and An-12.
Of course, no conversion ever happened, as metallurgy on An-10 centre wing box turned incompatible with rough fields/frequent operations mode Aeroflot ran them on. After a couple of spectacular fatigue crashes, An-10 was unceremoniously retired, while An-12 continues to soldier on.

DL_Mech wrote:

Newark727 wrote:

In addition to the Swedish examples, "Final Cut: The Post-War Boeing B-17 Flying Fortress" by Scott Thompson notes that a single B-17 was also civilianized by Boeing and TWA. Registrations were NX4600 and NL1B. No photos of the interior, and it may not have been used for scheduled service, but you might consider following up on this book if you're curious.

I believe it was only used for VIP transport. It was re-designated Model 299AB.

http://aviationtrivia.blogspot.com/2010/06/although-in-excess-of-25-different.html


From: https://www.dembrudders.com/uploads/1/2 ... m_orig.png


From:http://p8.storage.canalblog.com/86/80/871230/65687410.jpg

Many more photos here (post #28):

https://ww2aircraft.net/forum/threads/one-for-trebor.40045/page-2

I'm getting more and more curious about these B-17 conversions. I'm gonna have to see if SAS has any info on their conversions and where and for how long they flew them. Considering they even went to the point of lengthening the fuselages it sounds like they were serious about using them.

I wonder what this TWA example was like to fly in as well. Soundproofing was... more or less non-existent in the original airframe. If TWA used it for VIP transport or something I would assume they brimmed them with sound deadening. Neither interior nor seats scream "executive" though.

I believe there was also a rare C-108 serving as VIP aircraft for Douglas MacArthur. Though I don't know how this one was appointed. 25 were built for troop carrying and 8 for officer transports. I wonder what happened to these after the war. If they soldiered on in some smaller passenger outfit? I'm going to assume they were relegated to cargo and/or scrapped.

Phosphorus wrote:

Leovinus wrote:

I wish there was a "like" button to the comments in this thread.

A lot of aircraft have a heavy bomber heritage in their airframes as a lot of you point out. Especially Russian aircraft, but also mighty beasts like the Boeing B-377. In fact it's quite fun to see it all listed. Just shows you how much cross-over there was between military and civilian aircraft way back when. Some more overt than others, but all interesting.

For the this particular topic I'm personally more focused on the bombers airlines "slapped seats into", like the Lancastrian or Liberator Express and their ilk, than what came after them.

More interesting still is that this practice sort of ended after WW2. Lockheed had plans for civilian versions of both the Starlifter (which according to wikipedia was much more than paper proposals) and the C-5 Galaxy. Which sort of adhere to the "slap some seats into it" vibe. There were whispers of Antonov An-22's in passenger configurations, but this was more of a paper idea than real proposal so far as I know. The Canadair CL-44 might sort of count. Though it sort of fails as it was a military transport conversion based on the civilian Britannia, that got re-converted for civilian use by Icelandic airline Loftleiðir. So it sort of cheated by not being entirely military in origin.

I suppose the world had moved too far after WW2. Expectations were probably for more purpose built and thus more efficient aircraft than conversions could ever be, and there was no lack of good aircraft or funding to get them once economies recovered.

No idea on An-22 options, but it's actually open knowledge that Antonov An-10 and An-12 were a parallel design. There was even a conversion kit presumably developed, to fit An-10 with a ramp (one-way ticket, though, impossible to convert back into pax configuration). As a result, cockpit is basically separately pressurized on both An-10 and An-12.
Of course, no conversion ever happened, as metallurgy on An-10 centre wing box turned incompatible with rough fields/frequent operations mode Aeroflot ran them on. After a couple of spectacular fatigue crashes, An-10 was unceremoniously retired, while An-12 continues to soldier on.

That's interesting. I didn't know about the fatigue issues with the An-10. The An-12 seems to be a proper tank though. Soldiering on.

The An-22 conversion was nothing but a paper project. I've never seen any design sketches of it though. Apparently a two deck version was proposed with seating for 724 passengers. Far outstripping any demand for travel in the Soviet sphere at the time. Or anywhere else for that matter. These mega proposals always fall flat on that hurdle.

Bomber conversions seem to have grown in popularity primarily among feeder airlines or small operators where their ruggedness was appreciated. I assume thats why especially the Soviet civilian designs were so heavily based on military aircraft. Poor runways and FOD risk was a more prevalent concern than in the west. I find it kind of funny that the two Tupolev Tu-4 designs never made it to production however. Russian sources are harder to come by for me, so I couldn't say why.

Like the Tu-70


Or Tu-75

jeffrey0032j wrote:

starrion wrote:

Most Boeing narrowbodies have the fuselage of the 707, which shares a common ancestor with the KC-135. It wasn't converted, but the two families are pretty close.

The KC135 fuselage is narrower than the 707, and can only fit 5 abreast instead of 6.

That's what he said! They share a "common ancestor", which is the Dah80 prototype which had a 5 abreast configuration. In developing the KC-135 family they kept 5 abreast because thats what the customer [USAF] wanted, With the B707 most [all?] subsequent Boeing narrow bodies the customers wanted 6 abreast so Boeing gave it to them.
BTW You can see the Dash 80 in the Air & Space museum's annex at Dulles Airport.

Gemuser

Check out B-17E 41-2596 Desert Rat being restored. It was converted to a XC-108 during WWII and now being restored back to a B-17E. They talk about some of the mods from a bomber to a Freighter.

I've done some mor sleuthing and come across two other examples of bombers turned passenger aircraft. Though in this case it seems to have been much, much, sneakier.

In the run-up to WW2 Germany was increasingly skirting the Versailles treaty with regards to military buildup and production. I've known for a long time that a lot of their record breaking aircraft were meant to be prototypes for fighter aircraft. I didn't know that two of their primary bomber aircraft used "high speed passenger transports" as their way of circumventing regulations.

Whereas the Focke-Wulf Condor and the Junkers Ju-90 were passenger aircraft turned reconnaissance and bomber aircraft (though the Ju-90 had the wings and empennage of the aborted Ju-89 long range bomber, so it's definitely an edge case) the Heinkel He-111 C and G and Junkers Ju-86 were bombers developed under the guise of passenger aircraft. Or so it would seem at least. I'm mostly connecting the dots from historical knowledge of German rearmament and the "happy coincidence" of Lufthansa ordering high speed passenger aircraft of this calibre and size. So fitting for medium range high speed bombers.

The Junkers Ju-86 did see quite widespread use however. And looked like quite a nifty little airliner.

Bomber:


Passenger:


Interior:


The Heinkel is more difficult to find information on though. It was seemingly produced in far fewer numbers than the Ju-86. It had a stepped cockpit and faired nose. Looking quite handsome outside, though the inside is unknown to me. A picture of it is available on Flickr:
https://www.flickr.com/photos/27862259@N02/5924151118/

Leovinus wrote:

Phosphorus wrote:

Leovinus wrote:

I wish there was a "like" button to the comments in this thread.

A lot of aircraft have a heavy bomber heritage in their airframes as a lot of you point out. Especially Russian aircraft, but also mighty beasts like the Boeing B-377. In fact it's quite fun to see it all listed. Just shows you how much cross-over there was between military and civilian aircraft way back when. Some more overt than others, but all interesting.

For the this particular topic I'm personally more focused on the bombers airlines "slapped seats into", like the Lancastrian or Liberator Express and their ilk, than what came after them.

More interesting still is that this practice sort of ended after WW2. Lockheed had plans for civilian versions of both the Starlifter (which according to wikipedia was much more than paper proposals) and the C-5 Galaxy. Which sort of adhere to the "slap some seats into it" vibe. There were whispers of Antonov An-22's in passenger configurations, but this was more of a paper idea than real proposal so far as I know. The Canadair CL-44 might sort of count. Though it sort of fails as it was a military transport conversion based on the civilian Britannia, that got re-converted for civilian use by Icelandic airline Loftleiðir. So it sort of cheated by not being entirely military in origin.

I suppose the world had moved too far after WW2. Expectations were probably for more purpose built and thus more efficient aircraft than conversions could ever be, and there was no lack of good aircraft or funding to get them once economies recovered.

No idea on An-22 options, but it's actually open knowledge that Antonov An-10 and An-12 were a parallel design. There was even a conversion kit presumably developed, to fit An-10 with a ramp (one-way ticket, though, impossible to convert back into pax configuration). As a result, cockpit is basically separately pressurized on both An-10 and An-12.
Of course, no conversion ever happened, as metallurgy on An-10 centre wing box turned incompatible with rough fields/frequent operations mode Aeroflot ran them on. After a couple of spectacular fatigue crashes, An-10 was unceremoniously retired, while An-12 continues to soldier on.

That's interesting. I didn't know about the fatigue issues with the An-10. The An-12 seems to be a proper tank though. Soldiering on.

The An-22 conversion was nothing but a paper project. I've never seen any design sketches of it though. Apparently a two deck version was proposed with seating for 724 passengers. Far outstripping any demand for travel in the Soviet sphere at the time. Or anywhere else for that matter. These mega proposals always fall flat on that hurdle.

Bomber conversions seem to have grown in popularity primarily among feeder airlines or small operators where their ruggedness was appreciated. I assume thats why especially the Soviet civilian designs were so heavily based on military aircraft. Poor runways and FOD risk was a more prevalent concern than in the west. I find it kind of funny that the two Tupolev Tu-4 designs never made it to production however. Russian sources are harder to come by for me, so I couldn't say why.

Like the Tu-70


Or Tu-75

Adapting B-29 design to Soviet manufacturing was enough grief for Tupolev (both Andrei and his bureau) already. Andrei Tupolev personally had a love-hate relationship with B-29/Tu-4. He admired the original, he knew how advanced it was, he knew where he could still improve it, after all the reverse engineering. And he was under strict orders to make a copy, not an upgrade. Folks who worked for him said that it was a very special moment in Tupolev's life, and he was not exactly himself when he had to accomplish that task. He obviously was much more comfortable doing what he was best at: designing airplanes, and using every trick in the book to get resources to design them, and then get them built. Slime, politics, backdoor deals, browbeating opposition -- he reveled in this. B-29/Tu-4 was neither: he would get all the resources he would ask for, but he could not use them for advancing the design. Only to copy. Talk about frustration.

That neither Tu-70 nor Tu-75 got anywhere leaves us with very few options: either indigenous designs (particularly Il-12 and Il-14) were more than adequate to the requirements of the day, and Tu-70/75 were both hopelessly superfluous. Or Tupolev was disheartened enough, and conscious enough that these are just manicured redesigns of B-29, not to use his muscle to push them through.

This thread is great, thanks to all who have posted.

I have read that Chuchill used a VIP B-24 during World War 2. Does anyone have any pictures of the interior? I believe I read somewhere that the passenger compartment was rigged up in the bomb bay, cold, drafty, loud, and uncomfortable.

Phosphorus wrote:

Leovinus wrote:

Phosphorus wrote:

No idea on An-22 options, but it's actually open knowledge that Antonov An-10 and An-12 were a parallel design. There was even a conversion kit presumably developed, to fit An-10 with a ramp (one-way ticket, though, impossible to convert back into pax configuration). As a result, cockpit is basically separately pressurized on both An-10 and An-12.
Of course, no conversion ever happened, as metallurgy on An-10 centre wing box turned incompatible with rough fields/frequent operations mode Aeroflot ran them on. After a couple of spectacular fatigue crashes, An-10 was unceremoniously retired, while An-12 continues to soldier on.

That's interesting. I didn't know about the fatigue issues with the An-10. The An-12 seems to be a proper tank though. Soldiering on.

The An-22 conversion was nothing but a paper project. I've never seen any design sketches of it though. Apparently a two deck version was proposed with seating for 724 passengers. Far outstripping any demand for travel in the Soviet sphere at the time. Or anywhere else for that matter. These mega proposals always fall flat on that hurdle.

Bomber conversions seem to have grown in popularity primarily among feeder airlines or small operators where their ruggedness was appreciated. I assume thats why especially the Soviet civilian designs were so heavily based on military aircraft. Poor runways and FOD risk was a more prevalent concern than in the west. I find it kind of funny that the two Tupolev Tu-4 designs never made it to production however. Russian sources are harder to come by for me, so I couldn't say why.

Like the Tu-70


Or Tu-75

Adapting B-29 design to Soviet manufacturing was enough grief for Tupolev (both Andrei and his bureau) already. Andrei Tupolev personally had a love-hate relationship with B-29/Tu-4. He admired the original, he knew how advanced it was, he knew where he could still improve it, after all the reverse engineering. And he was under strict orders to make a copy, not an upgrade. Folks who worked for him said that it was a very special moment in Tupolev's life, and he was not exactly himself when he had to accomplish that task. He obviously was much more comfortable doing what he was best at: designing airplanes, and using every trick in the book to get resources to design them, and then get them built. Slime, politics, backdoor deals, browbeating opposition -- he reveled in this. B-29/Tu-4 was neither: he would get all the resources he would ask for, but he could not use them for advancing the design. Only to copy. Talk about frustration.

That neither Tu-70 nor Tu-75 got anywhere leaves us with very few options: either indigenous designs (particularly Il-12 and Il-14) were more than adequate to the requirements of the day, and Tu-70/75 were both hopelessly superfluous. Or Tupolev was disheartened enough, and conscious enough that these are just manicured redesigns of B-29, not to use his muscle to push them through.

Sounds as though you've read his biography. If there is one in English I would certainly want to read it.

It was a strange decision by the politburo to force a strict copy. I can see how a strict copy of the initial airframe might have made a modicum of sense. The leadership knew it obviously worked and had a great and pressing need for a long range bomber. But not allowing a "Tu-4B" or the like to be developed by one of the countries premier aircraft designers is a bit baffling. Especially as it was used for so many purposes. Even slight improvements could have had far reaching consequences for a production run of 847 aircraft. In the end we were graced with the Tu-95 and the Tu-114, but it would be some ways off.

What strikes me with Tupolev is that, bar a few exceptions, all of his civilian airliners were bomber derivatives. Same wings, landing gears, and empennage generally. Or at least closely related derivatives. Probably lessening the tooling costs substantially and shortening design and development time. Whereas Ilyushin seems to have been given broader mandate to make purpose built civilian airliners with their own tooling. The Il-18, Il-62, Il-86 and 96 were all purpose-built civilian aircraft. Sharing no tooling with military examples so far as I know. Tupolev have two as far as I know. The beautiful Tu-144, and the work-horse Tu-154.

Fun fact is that the Tu-144 actually began as a supersonic bomber concept which got dusted off (The Sukhoi T-4 was the eventual result of that initial concept requirement) to produce a civilian aircraft. It was later proposed as a supersonic missile carrier. Apparently it was a seriously studied proposal that fell through due to shifting interests in warfare and tactics.

SteelChair wrote:

This thread is great, thanks to all who have posted.

I have read that Chuchill used a VIP B-24 during World War 2. Does anyone have any pictures of the interior? I believe I read somewhere that the passenger compartment was rigged up in the bomb bay, cold, drafty, loud, and uncomfortable.

Here is a picture of a RAF liberator converted. As you can see there is very little finesse. Naked metal fuselage covered in what looks like plastic or tarpaulin, possibly insulated behind it? Chairs that look like they'd buckle in light chop. And this is an example that looks GOOD. I've seen far, far, worse examples. Churchills might have been better appointed. I simply don't know. I would hope it was though.

Leovinus wrote:

SteelChair wrote:

This thread is great, thanks to all who have posted.

I have read that Chuchill used a VIP B-24 during World War 2. Does anyone have any pictures of the interior? I believe I read somewhere that the passenger compartment was rigged up in the bomb bay, cold, drafty, loud, and uncomfortable.

Here is a picture of a RAF liberator converted. As you can see there is very little finesse. Naked metal fuselage covered in what looks like plastic or tarpaulin, possibly insulated behind it? Chairs that look like they'd buckle in light chop. And this is an example that looks GOOD. I've seen far, far, worse examples. Churchills might have been better appointed. I simply don't know. I would hope it was though.

Conversion for government VIP transport duty is a whole different ball game. US has a tradition of those, going back to Douglas Dolphin. You can argue that these are always conversions, either way -- when they were civil aircraft, pressed into USAF/USN VIP transport role (Boeing 314, Constellation, VC-25, C-137, whatever), they become militarized. And when they were originally military aircraft, they are also converted to carry pax (C-54, B-24 notably), so a conversion of sorts.

In WWII, USSR had at least a single of Pe-8 (a.k.a. TB-7) fitted to VIP duty, taking Molotov to Britain and later USA. On the first leg, they flew at 12.000 meters or so over occupied Europe, too high to be bothered by Nazis.

In Gernany, at least one Fw 200 Condor, after full switch to manufacturing military frames only, was actually built to a VIP specification for Hitler.

About conversion for Churchill -- films tend to depict his flights as miserable experiences, with sitting on benches parallel to the hull, always shuddering with cold. No idea how accurate that would be.

Leovinus wrote:

Phosphorus wrote:

Leovinus wrote:

That's interesting. I didn't know about the fatigue issues with the An-10. The An-12 seems to be a proper tank though. Soldiering on.

The An-22 conversion was nothing but a paper project. I've never seen any design sketches of it though. Apparently a two deck version was proposed with seating for 724 passengers. Far outstripping any demand for travel in the Soviet sphere at the time. Or anywhere else for that matter. These mega proposals always fall flat on that hurdle.

Bomber conversions seem to have grown in popularity primarily among feeder airlines or small operators where their ruggedness was appreciated. I assume thats why especially the Soviet civilian designs were so heavily based on military aircraft. Poor runways and FOD risk was a more prevalent concern than in the west. I find it kind of funny that the two Tupolev Tu-4 designs never made it to production however. Russian sources are harder to come by for me, so I couldn't say why.

Like the Tu-70


Or Tu-75

Adapting B-29 design to Soviet manufacturing was enough grief for Tupolev (both Andrei and his bureau) already. Andrei Tupolev personally had a love-hate relationship with B-29/Tu-4. He admired the original, he knew how advanced it was, he knew where he could still improve it, after all the reverse engineering. And he was under strict orders to make a copy, not an upgrade. Folks who worked for him said that it was a very special moment in Tupolev's life, and he was not exactly himself when he had to accomplish that task. He obviously was much more comfortable doing what he was best at: designing airplanes, and using every trick in the book to get resources to design them, and then get them built. Slime, politics, backdoor deals, browbeating opposition -- he reveled in this. B-29/Tu-4 was neither: he would get all the resources he would ask for, but he could not use them for advancing the design. Only to copy. Talk about frustration.

That neither Tu-70 nor Tu-75 got anywhere leaves us with very few options: either indigenous designs (particularly Il-12 and Il-14) were more than adequate to the requirements of the day, and Tu-70/75 were both hopelessly superfluous. Or Tupolev was disheartened enough, and conscious enough that these are just manicured redesigns of B-29, not to use his muscle to push them through.

Sounds as though you've read his biography. If there is one in English I would certainly want to read it.

It was a strange decision by the politburo to force a strict copy. I can see how a strict copy of the initial airframe might have made a modicum of sense. The leadership knew it obviously worked and had a great and pressing need for a long range bomber. But not allowing a "Tu-4B" or the like to be developed by one of the countries premier aircraft designers is a bit baffling. Especially as it was used for so many purposes. Even slight improvements could have had far reaching consequences for a production run of 847 aircraft. In the end we were graced with the Tu-95 and the Tu-114, but it would be some ways off.

What strikes me with Tupolev is that, bar a few exceptions, all of his civilian airliners were bomber derivatives. Same wings, landing gears, and empennage generally. Or at least closely related derivatives. Probably lessening the tooling costs substantially and shortening design and development time. Whereas Ilyushin seems to have been given broader mandate to make purpose built civilian airliners with their own tooling. The Il-18, Il-62, Il-86 and 96 were all purpose-built civilian aircraft. Sharing no tooling with military examples so far as I know. Tupolev have two as far as I know. The beautiful Tu-144, and the work-horse Tu-154.

Fun fact is that the Tu-144 actually began as a supersonic bomber concept which got dusted off (The Sukhoi T-4 was the eventual result of that initial concept requirement) to produce a civilian aircraft. It was later proposed as a supersonic missile carrier. Apparently it was a seriously studied proposal that fell through due to shifting interests in warfare and tactics.

I cannot attest to truthfulness of the idea that "Tu-144 actually began as a supersonic bomber concept which got dusted off". Maybe it did, but all I know was that Tupolev was working on Tu-144 specifically as a pax plane, period.

Regarding different design philosophies between competing design houses -- they were exactly those, different design philosophies. Andrei Tupolev believed in "Quick and dirty wins the day" or something like that. He was ready to compromise aerodynamic and engineering rigor, using quick fixes -- provided they worked.
Tu-104 aerodynamics proved this concept has an Achilles heel, when you are on the bleeding edge of the design of the day. Infamous "pitch-up" maneuver first scared, and then killed a few Tu-104 crews (and their passengers) before Andrei Tupolev had to stop his typical "your pilots are crap, learn to fly my perfect planes first", shut his mouth, and go back to the drawing board. After https://en.wikipedia.org/wiki/1958_Aero ... nash_crash he had to redesign the thing, as the crew narrated their experience in a way a test pilot would, reporting what went wrong all the way to impact.

Anyway, Andrei Tupolev would use anything available to speed things up, and that manifested in the cross-usage of things between military and civilian sides, as you observed.
Tu-144 was designed by his son, Alexei -- a different sort of fellow, with a different set of requirements (first supersonic civil pax aircraft in the world). He probably could not, and probably was not inclined to, endlessly reuse hardware from subsonic side (military or civil).

Regarding Tu-4B. First, again, Tupolev hated Tu-4; the lore goes internal project name was "B-4", as Tupolev was loathe to call a plane he didn't design with his name. Alas, the decision was not his, and Tu-4 it was.
Second, Tu-4 never became an exact copy, regardless. Famously, hull metallurgy could not be replicated without basically rebuilding Soviet almunium industry, for that project alone. Exact alloy could be eventually developed, but the metal thickness of the original B-29 frame (uniform thickness in fraction of inches, rather than metric decimals) made the exercise useless. So a combination of thicker-thinner of domestically manufactured alloys was used. There were other challenges as well. Tu-4 turned out to be heavier, and was pressed into service regardless.

Also, USSR was a planned economy. Running large batches of things, and making everything mutually replaceable and compatible made sense. Jet engine was already available, and Tu-16 (still in service in China today) would fly within 5 years from Tu-4. Probably, it made sense to close the Tu-4 chapter, transfer responsibility to manufacturing industry and the Air Force, and move on.

East Germany had some former Junkers engineering team building the "first German jet passenger aircraft", Baade 152 in the 1950s. While it was not a bomber itself it was a derivative of the Samoljot 150 jet bomber the same team had built in the Soviet Union before based on research that group had done in WW2 for the Germans.

The Baade 152 has some high wing bomber layout with the main spar led through the passenger cabin and some bomber gear to leave room for the (non existing) bomb bay in the center of gravity.
Original East German promo film:
https://youtu.be/_cURB_AEoR4

Phosphorus wrote:

I cannot attest to truthfulness of the idea that "Tu-144 actually began as a supersonic bomber concept which got dusted off". Maybe it did, but all I know was that Tupolev was working on Tu-144 specifically as a pax plane, period.

I meant it in the absolutely loosest sense. R&D that went into the Tupolev proposal for what became the Sukhoi T-4, among them the Tu-125 and Tu-135 bombers, was used during the Tu-144 project according to http://www.globalsecurity.org articles on the different aircraft. You could say it has a vague "lineage". So you're right to balk at any suggestion that the Tu-144 was a bomber derivative. As far as I understand it, it simply traces ideas from earlier military work. I've attached a picture from one of the articles from globalsecurity purporting to show one of several design suggestions of the Tu-135, already with civilian use in mind:



The Tu-144 is one of my favourite aircraft. It's history, development, and service is incredibly muddled and fascinating.

And I've got to say: You're intimate knowledge of the men involved on the Russian side of aircraft development is a tantalising treat! I am going to assume you have much better, perhaps primary, sources from which to pull information than I do. Limited as I am to English and mostly the web.

Leovinus wrote:

Phosphorus wrote:

I cannot attest to truthfulness of the idea that "Tu-144 actually began as a supersonic bomber concept which got dusted off". Maybe it did, but all I know was that Tupolev was working on Tu-144 specifically as a pax plane, period.

I meant it in the absolutely loosest sense. R&D that went into the Tupolev proposal for what became the Sukhoi T-4, among them the Tu-125 and Tu-135 bombers, was used during the Tu-144 project according to http://www.globalsecurity.org articles on the different aircraft. You could say it has a vague "lineage". So you're right to balk at any suggestion that the Tu-144 was a bomber derivative. As far as I understand it, it simply traces ideas from earlier military work. I've attached a picture from one of the articles from globalsecurity purporting to show one of several design suggestions of the Tu-135, already with civilian use in mind:



The Tu-144 is one of my favourite aircraft. It's history, development, and service is incredibly muddled and fascinating.

And I've got to say: You're intimate knowledge of the men involved on the Russian side of aircraft development is a tantalising treat! I am going to assume you have much better, perhaps primary, sources from which to pull information than I do. Limited as I am to English and mostly the web.

Not intimate enough. I share the hometown with Antonov company, and happened to know some folks who worked there over the years.
The knowledge of the rest of design houses and production plants is rather second-hand or from books.

Regarding supersonic developments in USSR -- those were indeed shared, at least on research stages, with military leading the way. Sukhoi T4 design was grabbed, AFAIR, and massively redeveloped by Tupolev team, into Tu-160.
Now, Tu-144, is from my humble viewpoint, is basically two (and some would argue three) airplanes -- first being Tu-144 (original), first flown in 1968. Second would be canard-equipped Tu-144S. Third would be the re-engined Tu-144D, probably, though the latter two IMHO are subtypes of the same plane; these flew commercially from 1975 or thereabouts. And only these latter could receive any serious contribution from Sukhoi T-4, though I have no idea if that ever happened or not.

My understanding is the RAF, and other Commonwealth countries, operated Lockhead Hudson light bomber was a Lockhead Electra derivative. The US airforce also operated variants.
Likewise the Ventura bomber operated by the same countries was a derivative of the Lockhead Lodestar.
Postwar some of these were converted into passenger aircraft in the US.
In NZ Lockhead Loadstars preceded DC3s as the only twin engined aircraft employed as agricultural aircraft dispersing fertiliser onto rugged hill country farms. Certainly the DC3s were modified to single pilot configuration.

Unfortunately no pictures but here's a story about Churchill's Liberator:

https://www.airspacemag.com/history-of- ... 66507/?all

Here a link to a picture of Churchill by the entrance hatch to the B-24 but I couldn't find any of the interior.

https://www.pinterest.com/pin/17381148533545486/

Remove the S in https if there is trouble in opening the pages.

Toenga wrote:

My understanding is the RAF, and other Commonwealth countries, operated Lockhead Hudson light bomber was a Lockhead Electra derivative. The US airforce also operated variants.
Likewise the Ventura bomber operated by the same countries was a derivative of the Lockhead Lodestar.
Postwar some of these were converted into passenger aircraft in the US.
In NZ Lockhead Loadstars preceded DC3s as the only twin engined aircraft employed as agricultural aircraft dispersing fertiliser onto rugged hill country farms. Certainly the DC3s were modified to single pilot configuration.

The Electra and the DC-3 were both converted into bombers. The Lockheed Ventura and the Douglas Bolo if I recall. The Focke Wulf Condor was pressed into bomber service as well. Kind of an interesting reversal. I know there were plans for a bomber based on the Constellation that never saw the light of day.

ClipperYankee wrote:

Unfortunately no pictures but here's a story about Churchill's Liberator:

https://www.airspacemag.com/history-of- ... 66507/?all

Here a link to a picture of Churchill by the entrance hatch to the B-24 but I couldn't find any of the interior.

https://www.pinterest.com/pin/17381148533545486/

Remove the S in https if there is trouble in opening the pages.

Fascinating reading, thank you for that. Precisely the kind of stuff I've been looking for with regards to passenger and crew stories of these beasts. I often find that hobbyists trend towards the technical of aircraft, which to me misses the wider context that make them so special. The Liberator sounds like a dreary machine to fly on as a passenger. I know BOAC only used their passenger versions for a very brief period. And the picture is emerging that they were rattly, cold, and uncomfortable things in passenger guise. I suppose there Is only so much you can do. And in war time effort was probably also at a minimum. But I'm still blown away by the comparative luxury in accommodation fitted to Halfords and Lancastrians. I wonder what the York was like for Churchill considering it was dedicated for passenger transport. I'm going to assume it was a fair bit more comfortable. Quite a few were built too, serving with various airlines for decades.

Phosphorus wrote:

Leovinus wrote:

Phosphorus wrote:

I cannot attest to truthfulness of the idea that "Tu-144 actually began as a supersonic bomber concept which got dusted off". Maybe it did, but all I know was that Tupolev was working on Tu-144 specifically as a pax plane, period.

I meant it in the absolutely loosest sense. R&D that went into the Tupolev proposal for what became the Sukhoi T-4, among them the Tu-125 and Tu-135 bombers, was used during the Tu-144 project according to http://www.globalsecurity.org articles on the different aircraft. You could say it has a vague "lineage". So you're right to balk at any suggestion that the Tu-144 was a bomber derivative. As far as I understand it, it simply traces ideas from earlier military work. I've attached a picture from one of the articles from globalsecurity purporting to show one of several design suggestions of the Tu-135, already with civilian use in mind:



The Tu-144 is one of my favourite aircraft. It's history, development, and service is incredibly muddled and fascinating.

And I've got to say: You're intimate knowledge of the men involved on the Russian side of aircraft development is a tantalising treat! I am going to assume you have much better, perhaps primary, sources from which to pull information than I do. Limited as I am to English and mostly the web.

Not intimate enough. I share the hometown with Antonov company, and happened to know some folks who worked there over the years.
The knowledge of the rest of design houses and production plants is rather second-hand or from books.

Regarding supersonic developments in USSR -- those were indeed shared, at least on research stages, with military leading the way. Sukhoi T4 design was grabbed, AFAIR, and massively redeveloped by Tupolev team, into Tu-160.
Now, Tu-144, is from my humble viewpoint, is basically two (and some would argue three) airplanes -- first being Tu-144 (original), first flown in 1968. Second would be canard-equipped Tu-144S. Third would be the re-engined Tu-144D, probably, though the latter two IMHO are subtypes of the same plane; these flew commercially from 1975 or thereabouts. And only these latter could receive any serious contribution from Sukhoi T-4, though I have no idea if that ever happened or not.

I have seen models of a bomber with wing edges that swept down XB70 style that was clearly derived from the TU-144 design - although the wing leading edges were extended further forward to the nose of the plane. The tail looked very similar.

I don’t know what this was called. It appears to have been some sort of study that never made reality.

This is the one of the very best threads I’ve seen on this site, absolutely fascinating

A number of airlines, including BOAC, Qantas, Ansett, NZ National Airways Corporation and TEAL (the last two later subsumed into Air NZ) used the Short Sunderland and/or its commercial derivative, the Sandringham, in commercial service.

Interesting to see bombers converted for pax use. But what about the other way around?

I think I saw in another thread how certain early Soviet airliners could be readily-converted towards bomber-use, in the event of war. Would love to see if there's any more evidence of that.

And I'd rather find out here rather than doing lots of searches. This seems like the thread for that.

USTraveler wrote:

Interesting to see bombers converted for pax use. But what about the other way around?

I think I saw in another thread how certain early Soviet airliners could be readily-converted towards bomber-use, in the event of war. Would love to see if there's any more evidence of that.

And I'd rather find out here rather than doing lots of searches. This seems like the thread for that.

The book "On the beach" describes the start of nuclear Armageddon coming on wings of Il-62 -- AFAIR, it's an Albanian Il-62 bringing nuke and detonating it over USA. Stunned, surviving US chain of command makes a conclusion "Soviet-built airliner brought nuke = Soviets nuked us" and retaliates, despite Soviet pleas "it wasn't us", and then it deteriorates into a triangle of nuclear warfare (China hitting both NATO and USSR with cobalt-based nukes, and USSR and NATO nuking each other into ashtray state, or something to that nature).

A thesis many on this site would take to heart, even at this day, was: as the catalyst of humanity annihilation was a rogue nation owning an Il-62, the wise idea was never to let small countries buy long-range airliners. Only UN permanent SC members (5 countries) could own those, and that was already stretching it.

Now, whether you could convert a Tu-134 or Il-62 into a real, bomb-bay door-equipped bomber? I cannot visualize it, but maybe someone more knowledgeable could. Kamikaze missions, with an airliner being a disposable missile to deliver a payload, don't count, IMHO.
I could well see Aeroflot withdrawing capacity from pax operations, and shifting it to move troops around. Maybe use the planes for rapid deployment into still "hot" areas. Not really bombing.

For example, during Soviet (rather, Warsaw Pact) invasion of Czechoslovakia, Prague Airport tower was taken over by a Soviet commando team that arrived on a plane to that same Prague airport. They issued a fake distress signal, got a landing clearance, and the rest was history. Whether the "distressed" plane flew under Aeroflot or Soviet Air Force callsign, I do not remember, but it was a pax type or mil equivalent (think An-24 vs An-26 for example; or An-10 vs. An-12)

Phosphorus...

Sounds very riveting! Like a great novel. Almost too close for comfort due to the actual possibility of it all.

It seems like some of the Soviet-era airliners could have easily had "hard-points" to mount externally-carried bombs...

DavidByrne wrote:

A number of airlines, including BOAC, Qantas, Ansett, NZ National Airways Corporation and TEAL (the last two later subsumed into Air NZ) used the Short Sunderland and/or its commercial derivative, the Sandringham, in commercial service.

I've only done cursory research into this, but the Short Solent and Sandringhams were apparently both Sunderland derived. And quite comfortable, sturdy, aircraft. BOAC wanted to phase them out rather quickly however. Using them out of necessity rather than any particular usefulness specific to flying boats. Which is why many of them quickly found themselves elsewhere after the war. I believe they left BOAC in the early 50s. Understandably so. BOAC's routes were flooded with airfields, and pressurised aircraft were both more comfortable and efficient than the flying boats. But Australia, Asia, and Africa, and South America still had lots of use of them.

Max Q wrote:

This is the one of the very best threads I’ve seen on this site, absolutely fascinating

Glad you like it! These are the kinds of discussions I wanted to have on Reddit, but couldn't. It's simply too geared towards short term discussions by its nature. Airliners.net, being a proper forum, is a much better... well... forum for discussion. So now I'm here

USTraveler wrote:

Phosphorus...

Sounds very riveting! Like a great novel. Almost too close for comfort due to the actual possibility of it all.

It seems like some of the Soviet-era airliners could have easily had "hard-points" to mount externally-carried bombs...

It is. https://en.wikipedia.org/wiki/On_the_Beach_(novel)
There are two movies based on it, 1950's vintage (Ava Gardner, Gregory Peck, Fred Astaire), and 2000's one.

Now, installation of hard points is something where someone more knowledgeable than me has to chime in. Except Antonov and Myasischev (and of course the entire Tu-114/95/142 grouping), Soviet large aircraft designers preferred clean wings, with engines away in the tail area.
What kind of consequences that has for potential hard-points -- no idea. Because it could go either way -- either a clean wing only, with no provision for large "something" hanging from it; or clean wing to better accommodate "something"? I don't know, someone more knowledgeable is needed.

I found a few wonderful sites with well sourced articles on the B-17 bomber conversions in Scandinavia and their long years of work. With a few amazing photos of their interiors as well, which is very rare. I highly recommend giving them a read.

https://worldairphotography.wordpress.com/2014/04/16/the-story-about-the-only-b-17-flying-fortress-in-the-royal-danish-air-force/

Though it does seem to be a translation of the following article in Swedish:
http://chefsingenjoren.blogspot.com/2011/08/se-bap.html

A high resolution side comparison from the American Air Museum in Britain of a standard B-17 and a post-conversion exemplar. Notice the elongated nose and the addition of windows for the passenger compartment:


Here is a short article in PDF form from http://www.bobsganderhistory.com with a focus on one of the transatlantic flights flown:
http://bobsganderhistory.com/SEBAN.pdf

And I can't help myself from linking to a Wikimedia photo of it in service:

BOAC actually used Mosquitoes during WW2 to carry I think just one VIP who sat in the bomb bay breathing oxygen, these flights were made to neutral countries in Europe

Leovinus wrote:

I found a few wonderful sites with well sourced articles on the B-17 bomber conversions in Scandinavia and their long years of work. With a few amazing photos of their interiors as well, which is very rare. I highly recommend giving them a read.

This was very fascinating, it looks decent enough inside but it must have been pretty rough/noisy.

Although it never made production or even testing, I also looked at North American's proposals for a passenger carrying version of the XB-70 with either a standard size and small passenger cabin at the front or a lengthened cabin section and shorter range. North American M-3000 SST. From the diagrams I've seen the passengers would have been jammed into it.

What was interesting is a comparison in size. The XB-70 is fairly large itself but the planned Boeing 2707 absolutely dwarfs it for size comparison, The L2000 Lockheed too. It's quite amazing just how large those American SSTs would have been.

I cannot post the source as it is on a rival internet site (so against the rules).

Phosphorus wrote:

USTraveler wrote:

Phosphorus...

Sounds very riveting! Like a great novel. Almost too close for comfort due to the actual possibility of it all.

It seems like some of the Soviet-era airliners could have easily had "hard-points" to mount externally-carried bombs...

It is. https://en.wikipedia.org/wiki/On_the_Beach_(novel)
There are two movies based on it, 1950's vintage (Ava Gardner, Gregory Peck, Fred Astaire), and 2000's one.

Now, installation of hard points is something where someone more knowledgeable than me has to chime in. Except Antonov and Myasischev (and of course the entire Tu-114/95/142 grouping), Soviet large aircraft designers preferred clean wings, with engines away in the tail area.
What kind of consequences that has for potential hard-points -- no idea. Because it could go either way -- either a clean wing only, with no provision for large "something" hanging from it; or clean wing to better accommodate "something"? I don't know, someone more knowledgeable is needed.

The Antonov converted bombers mostly had hard points attached to various parts of the fuselage with external weapons carriage. I suppose that was a simpler solution than overbuilding a wing for only very occasional use.

I'm treating this thread as my own memory repository at this point. So I thought I'd add more on the B-17's in Swedish use as I found an excellent source on them. I'm not sure I can share it as such, but I can do a few translations I'm sure.

In the Swedish magazine "Flyg", nr. 17 edition of 1944, several pages are devoted to an in depth review of the converted aircraft. It also answered some of my own questions regarding bomber conversions and the curious lack of them in use after the war more than briefly.

I'll translate from my native Swedish tongue to English a few of the paragraphs I found enlightening:

To fly on this >>Flying Fortress>>, be it the civilian version and that the F-17 is but an emergency solution to the Swedish intercontinental traffics aircraft problem, is nothing if not an experience. When flying as a passenger in this >>Trafficfortress>> able to walk about to visit the cargo bay, pilots and navigators as well as the flight mechanic while also able to crawl down to the radiooperator in the nose – not to mention the excitement of squeeze through the toilets back door, past the fairing of the tailwheel retraction mechanism and out to the forlorn gunners chair left at the rear. Where a gunner once sat in wild buffeting in violent escape manoeuvres from German anti-aircraft guns, fighters, or just turbulent weather. You can't but help to let your imagination play in your mind a tad.

The author, Gunnar Knutsson, was (among other things) amazed at the short start and landing distance achieved in the plane. He went on to explain the planes usefulness to Sweden thusly however:

ABA and SILA – All Swedes in fact – ought to be happy to have been given the chance to rebuild these diverted B-17s, which for now are on loan to Sweden and can be purchased after the war [...]. But this gratitude shouldn't distract from the fact that rebuilt bombers for civilian use is an emergency measure, only possible in wartime when no other suitable aircraft are available and that in peacetime will prove far too uneconomical based on their limited passenger and cargo carrying capacity.

He goes on to compare the Douglas C-54 and the DC-3 to the B-17's (named F-17, where the F stands for Felix. The surname of colonel Felix Hardison who was instrumental in making the entire endeavour possible). Noting that the C-54 could carry 55 in pressurised comfort, the DC-3 a mere 21, and the fortress a paltry 14. And the DC-3 could outdo the fortress on a 1500 distance carrying these 21 while burning 350 litres of fuel an hour. The F-17 with 14 passengers and 3 tons of cargo guzzling 700 and hour over roughly the same distance. Economics were obviously not on the side of the bomber. But one had to make do and mend. And this they certainly did. Gloriously.

What follows is descriptions on the fuselage modifications:

• Lengthening the nose by half a meter and widening it to make room for a mail/cargo bay in order to secure the centre of gravity.
• Adding to and in some place replacing radio equipment and modernising it with nationally sourced alternatives.
• Converting the cockpit instrumentation to metric and a few minor changes to instrument positions in order stay in line with Swedish norms at the time.
• Rebuilding the bomb bay into the main cargo hold with an electrical hoist.
• Rebuilding the original radio operators station into a passenger compartment for six passengers seated lengthwise along the hull (not a bench but individual and very plush and comfortable looking seats) with new windows installed above.
• In the immediately connected and step-less rear passenger compartment the seats are raised In a way commonly seen on busses in order to get the shoulder height to the point of maximum fuselage width. Two ordinary rows of seats, each with their own window, five on the right side and three on the left looking aft. At the very rear is a compartment for storing coats and luggage, a toilet (also with a window), and the entry door to the emptied out tail. Useful for storage if CG allows, though it's pointed out that steering cables are naked and could be impinged if the cargo shifts(!)
• All of the electrics in the aircraft have been completely redone as Swedish regulations didn't allow for unshielded/unprotected electrical wiring. Roof lighting, reading lights, and call buttons etc. was also added
• The entire fuselage was clad in a flame-retardant isolation as well as filt aside from nose and cargo bay. The inside of the passenger and crew compartments were additionally covered in canvas and leather.
• The original heating system was doubled and electrical circulation fans installed, most of it hidden out of sight. Fresh air could also be adjusted with a modicum of individually allowed modification.
• A new oxygen system was installed throughout. I'm assuming for emergency use as the aircraft was not pressurised.

I can attest from the images that the interior looks very comfortable. Like a slightly more spacious Lockheed Super Electra, and equally as well appointed. Though the seats are more bolstered and more in line with BOAC's of the same era with their weird round cushions each side of the head.

The article ends with a description of its capacity:

The civilian version of the >>Flying Fortress>> normally carries 4 crew and 14 passengers along with three tons of cargo, bagage, and post sans fuel and oil for a maximum range of 1 800 km. Flight weight is then 25,7 tons. The maximum allowable carry weight, including passengers and cargo, is around 5 tons.

It's a point of pride mention in the article that Boeing and several nations asked for the blueprints with a keen eye on potentially making their own conversions. Boeing praised the conversion quality and thoroughness as some of the finest work they'd ever seen apparently. A qualified ego boost for the company responsible. One Svenska Aeroplan Aktiebolag, better known as SAAB.

As others have said, this threat is fantastic and what all of a.net should be.

One other honorable mention: the behemoth Convair XC-99, the cargo/passenger adaptation of the B-36. I understand that this is not a converted bomber, as it has an entirely new fuselage, which is akin to the relationship between the B-29 and B377. But I just had to mention this awesome airplane because you can see its B-36 roots, because it actually flew, and because Pan Am ordered it. Amazing that a piston-driven airliner was going to have a MGTOW of 320,000lbs.

It was of course not to be. The Pratt&Whitney R-4360 was already a thermodynamic challenge, as it was difficult to keep the back rows of cylinders cool in operation. Placing the engine inside the wing so it could drive a pusher propeller was much worse, as the engine just cooked itself with inadequate ventilation. The 4360 was tough as it was on the Stratocruiser. This thing would have been impossible. Powerplant thermodynamics is one of the reasons the B-36 was not more successful.

Leovinus wrote:

As a preface to the topic I'd like to say hello. Just a thirty something aviation enthusiast joining your ranks from Sweden. Hello!

My interest in aviation is broad. After reading the excellent "Speedbird - The complete history of BOAC" by Robin Higham I became very curious about passenger converted bombers. It's obvious that early post-war Britain (airlines across the globe really) scrambled to fill civilian needs with bomber conversions. While plenty know of the Avro York, this aircraft mated a new fuselage to the wings of a Avro Lancaster, making it more of a new plane than a conversion.

Below are a few examples. I'd love to know more about how they were perceived by passengers and crew and what they looked like outside and in. In most cases pictures and stories are incredibly hard to come by. These planes were not seen as glamorous and served a stop-gaps. Therefore information is scarce; nothing more than slightly expanded footnotes.

BOAC Lancastrian
The BOAC Lancastrians were given rounded noses and converted the bomb bay into passenger accommodations. The slim fuselage posed challenges though, and the high fuel consumption made them incredibly uneconomical. They were used by BOAC and QANTAS for express services post-war until purpose built aircraft could be sourced. Plenty of other airlines used them as well, both for passengers and cargo.

Pictures below courtesy of https://travelupdate.com/sideways-seating-avro-lancastrian/. The article is well worth the read.

Outside


Interior of BOAC - Interesting sideways seating


Interior of BSAA - Slightly more conventional



Handley Page Halton
The Handley Page Halton is a slightly more shy beast. It never got quite the sales I'm assuming. I have precious little info about her and I'm very curious. So if you fine folks have more info I'd be delighted to hear it. It seems as though there was more space in the passenger cabin than the Lancastrian. Commonly a pannier was also added to the bottom of the fuselage. The purpose of which is unknown to me, possibly freight? Again, if you know more about her interiors and/or service and what passengers and crew thought about her it would be very valuable to me.

Exterior picture courtesy of Wikipedia


I have no interiors, but this cut-away courtesy of http://www.aviationancestry.co.uk shows it to be an interesting layout.


Consolidated C-87
The passenger liberator was, according to wikipedia, not a terribly pleasant aircraft for crew to fly. With many vices. Interiors that I've come across have also been incredibly sparse, with naked metal interiors and toilets with a "privacy curtain" in lieu of a proper door for a lot of them. BOAC had at least one in service, and I've got to wonder if the intriors of this example weren't better. Looking at the Lancastrian there seems to have been actual effort put into making it as nice as possible. I would love to see their Liberator interior. As a side note: I do love the fact that the faired nose looks a bit like a sperm whale or moomin (if you're familiar with the Finnish children's figures).

Exterior view courtesy of wikimedia


I've sourced the following picture from Reddit, there is no attribution as to actual source I'm afraid.


Boeing B-17 conversions
Boeing did have both an "official" conversion called the C-108, as well as other conversions. This might be the beast I know the least about that carried passengers. Boeing has an interesting article on their own Boeing Frontiers magazine about the Scandinavian examples which you can read more about here: https://www.boeing.com/news/frontiers/archive/2006/february/i_history.html

A picture from the same article


Discussion
There were other conversions, some I simply don't know about (so please do chip in), and others were converted for freight. And as interesting as freight handling is, I'm personally more interested in the trickier passenger conversions.

In a few cases I wonder why the likes of BOAC didn't adopt more conversions at the very end of the war years. The York is the only real effort to make a quick and easy "proper" airliner out of a bomber. There were also plenty of conversions of flying boat Short Sunderlands, and these airframes were eminently suitable and easy to convert. But it seems as though both the Halfords and the Liberators could have been lengthened and pressed into service for short to medium haul routes as well, though it would have required more effort.

Of course, the DC-3, DC-4, and Constellations were purpose built and better suited. But especially Britain suffered heavily from a debt burden. They didn't want to spend dollars which were necessary for other national interests. The economy working differently then than it does now means that dollar reserves were exceptionally valuable in a way that they aren't today in the same way. Which should have made how grown conversions economically viable propositions.

If BOAC would have accepted them is a different matter. BOAC had to compete with American and European airlines and had a sense, true or not, that bomber conversions would be donkeys racing stallions. And the storied Brabazon committee made no recommendations for bomber derived stop-gaps. Instead focusing wholly on new ventures in order to let British aircraft manufacturers catch up technologically. The Hadley Page Hastings military transport derived Hermes was the only one, and it was delayed far too much to be useful. Converting the unpressurised Hastings to a DC-4 competitor was too radical to be done in a timely manner as it turned out. I propose that had production of Yorks and lengthened/enlarged Haltons been done before wars end the need for the Hermes would never have arisen. Then again, had the Avro Tudor been persevered with the entire question would be moot. But what is the British aircraft industry but a huge list of depressing what-ifs?

What's evident is that they and others DID use bomber conversions. The stories of which are few but oh so tantalising. What was it like to fly on a SILA B-17? The Halford? A BSAA Lancastrian to South America? How were they used and why in airliner networks? It's simply a bit of a forgotten part of aviation history in my opinion. A small but important one.

TCA also operated Lancaster civilian conversion Lancastrians.

I didn’t see anyone mention the the famous ex-SAHA AIR ex-military 707s converted to airline use...even though SAHA is owned by the Iranian military. But some of their ex-707 fleet were formerly air-to-air refuelers.

TW870 wrote:

As others have said, this threat is fantastic and what all of a.net should be.

One other honorable mention: the behemoth Convair XC-99, the cargo/passenger adaptation of the B-36. I understand that this is not a converted bomber, as it has an entirely new fuselage, which is akin to the relationship between the B-29 and B377. But I just had to mention this awesome airplane because you can see its B-36 roots, because it actually flew, and because Pan Am ordered it. Amazing that a piston-driven airliner was going to have a MGTOW of 320,000lbs.

It was of course not to be. The Pratt&Whitney R-4360 was already a thermodynamic challenge, as it was difficult to keep the back rows of cylinders cool in operation. Placing the engine inside the wing so it could drive a pusher propeller was much worse, as the engine just cooked itself with inadequate ventilation. The 4360 was tough as it was on the Stratocruiser. This thing would have been impossible. Powerplant thermodynamics is one of the reasons the B-36 was not more successful.

The Convair XC-99 (The civilian version was to be named the Model 37) really hinged on turboprops being available for the production model so far as I recall. I can't find the source for that at the moment however, if someone does I'd be very happy.

I don't think a lot of people realise that at the change-over from ordinary props to jets and turboprops it was far from clear cut that jets would actually be the way forward. Their propulsive efficiency was abysmal. The De Havilland Comet showed that it was possible to make them economical on short to medium haul sectors however.

The problem with turboprops is that they are more mechanically complex. Development was slower than the pure jet. Had the turboprop actually come into production in a timely manner I think we'd have seen many more "simple" conversions though. Lockheed, Douglas and Boeing, all had designs on turboprop conversions or derivatives of their Constellations, DC-7s and B-377s, waiting on an engine. Lockheed went the furthest by trialing turboprops on the Connie, and Bristol had finally sorted the Britannia into a thoroughbred, but at that point pure jets hade matured enough. Jets became the future in the eyes of the public, and their higher speed outweighed their economy of operation for operative and passenger appeal.

Maybe I should make another thread for the likes of the XC-99, Bristol Brabazon, Lockheed Republic, and Saunders Roe Princess. The giants that failed. Yes, I think I just might.

Dominion301 wrote:

I didn’t see anyone mention the the famous ex-SAHA AIR ex-military 707s converted to airline use...even though SAHA is owned by the Iranian military. But some of their ex-707 fleet were formerly air-to-air refuelers.

They must have been awfully cramped considering the 707 tanker used the original, slimmer, fuselage that got redesigned into a wider 3+3 capable fuselage width for the civilian version.

In a way I'm grateful for Iran Air to have kept so many classics in the air. Not by choice obviously, but still.

Leovinus wrote:

Dominion301 wrote:

I didn’t see anyone mention the the famous ex-SAHA AIR ex-military 707s converted to airline use...even though SAHA is owned by the Iranian military. But some of their ex-707 fleet were formerly air-to-air refuelers.

They must have been awfully cramped considering the 707 tanker used the original, slimmer, fuselage that got redesigned into a wider 3+3 capable fuselage width for the civilian version.

In a way I'm grateful for Iran Air to have kept so many classics in the air. Not by choice obviously, but still.

But those weren’t the refuelling tankers like what the USAF has. If I’m not mistaken they were specially prepared 707-300 type aircraft with those large windows at the back. I could be wrong though.

I would have loved to fly in one or just have a good look at it and talk with the people flying them. Same as for the 747SP or the 747-100. You have to hand it to them keeping those beautiful old classics going and seemingly pretty well.