Twin Fuselage Aircraft: DOUBLE IMPACT OR DOUBLE TROUBLE?

Added: 2026-05-12

[00:00:00]historically speaking few combat aircraft are Swiss Army knives most of them have been designed and optimized to fulfill one role very well a couple of others less well and everything else pretty poorly but combat aircraft are also expensive and often time consuming to design and of course they're relatively expensive and resource hungry to build they have historically used up a high proportion of the best brains and the most exotic materials of given country at any one time for this reason down the decades designers have sometimes sought to adapt existing designs to fulfill new roles some of these adaptations have been wildly successful probably most famously the f-15e Strike Eagle some of them have been notably less successful for example my favorite Whipping Boy the Mig 27 although quite deep alterations in some design aspects overall both of these are in fact quite modest adaptations this video covers a much more ambitious evolutionary path namely the twin fuselage aircraft this is exactly what it sounds like take one conventional aircraft Park another identical aircraft next to it now figure out how to connect them together to create something with rather different performance characteristics as I'm about to go into reasons for these twin Fus large projects varied initially they were built to fulfill a different tactical need without the expense and Industrial stretch of starting with a blank sheet of paper such aircraft were Factory built as twins postwar they were considered as a way of extending the operational life of expensive but obsolete aircraft with comparatively small modifications these were to use already built and operated aircraft as their base materials and their construction was considered as late as the 1960s some articles suggest that the first serious twin fuselage aircraft was the fuer M9 of 1915 or thereabouts the M9 is an interesting case it does indeed have two identical fuselages in this case they are from the fuer M7 and they are joined by two Bay biplane wings with equal top and bottom span however the typically unorthodox fuer deviated from future imitators in the rest of the design each of the m seven fuselages is engineless essentially just a tail group in between them is a custom built in a cell that has an 80 horsepower urber inso engine in tractor configuration at the front and an identical engine at the back as a pusher the pilot sat in the middle of this blizzard of rotating cylinders exactly what the point of this design was is lost to history it's most likely an attempt to create an unarmed spotting or perhaps a bomber aircraft that could outrun its enemies at this point the interruptor gear had not been perfected and Fighters were generally quite rubbish another theory has it that there would be a gunner in each of the M7 fuselages able to fire unhindered by propellers irrespective of motif when the M9 flew for the first time after a rather long takeoff roll it exhibited pretty poor flight characteristics most notably the two fuselages flexed alarmingly suggesting that a major problem was not far away after one more test flight ER gave up and had the Prototype taken apart the M7 was itself a bust with only 20 made and even though structurally unsound the ends of their wings fluttered like a bird in Flight I imagine that was a little unnerving even in those more robust times the M9 is however helpful in that it defines what is what I would term a twin Fus a lar aircraft and what isn't I'm focusing here on aircraft that retain the engines in the original fuselages and hous the crew in one or both of them rather than in an additional cell happily the Great War threw up at least one example of this type of aircraft the Blackburn company named after the founders not the place was not the most original name of aircraft at the best of times Blackburn's response to the Zeppelin Panic of winter 1914 was a biplane SE plane with two fuselages separated by 10 ft the pilot was in one fuselage and the observer in the other there was no intercom so communication between the two was affected by the traditional means of yelling very loudly otherwise their aircraft was conventional for an early 1915 bipe being wood framed and fabric covered the wings were unequal in length and unstaggered engines were supposed to be 150 horsepower Smith static radial engines but these weren't very good so they were replaced by 100 horsepound gnomes this led to the aircraft being underpowered and lacking both climb rate and service ceiling in turn this led to the nine imaginatively named Blackburn twin blackburns or cubic blackburns as I prefer being essentially useless they couldn't climb high enough to drop the 241 Ranken darts that they were supposed to use against Zeppelins on top of the gas bags the ninth and final Blackburn cubed had 110 horsepower clergate engines fitted in an attempt to remedy the issue but they didn't have any positive effect on performance in practice although the aircraft entered service it never engaged a Zeppelin and they were ultimately broken up in 1917 it was a nearly 25e wait until the first somewhat effective twin fuselage combat aircraft entered service this was the hle h111 Zed and it came about as a result of operation sea line the planned invasion of the British Isles in 1940 part of the plan called for a massive Airborne assault in order to transport heavy equipment to The Landing zones the Luft vaer commissioned mmid and yunas to develop very large cargo gliders the winning mmid design designated me 263 had six times the carrying capacity of the Contemporary Yuna ju52 although SE lion was cancelled before the decision to proceed with the project that it occurred planning for Barbarosa led to renewed interest in it redesignated me 321 and nicknamed gigant it went into production an early issue the Luft varer encountered was the challenge of getting such a large and heavy aircraft airborne and keeping it there initially ju 90 airliners were used but these lacked sufficient power and speed to be operationally useful the next idea was to tow the gigant behind three me 110 Fighters taking off and flying in v formation the so-called trer schleps solved the speed issue but it was terrifically dangerous for the pilots who had to take off and fly in precise formation for extended periods of time apparently in an early test one of the jto rockets on the fully loaded gigant failed halfway through takeoff this induced a violent Yore which dragged one bf10 into the others all four aircraft crashed killing 129 people what was really needed was a powerful multi-engined aircraft with with extended range unfortunately no such aircraft existed in the German industrial plans aside from specialized planes like the wolf Condor which was both very expensive and needed for more vital roles then in early 1941 some bright spark hit on a potential idea rather than make something new they could simply connect together two twin engine H 1 11s adding a connector between the wings that carried a fifth engine each of these engines was a watercooled V12 dumo 211 that gave 1340 horsepower because experience showed that even these didn't give enough power for takeoff rocket assistance was sometimes also used in the form of two rockets beneath each fuselage and one under the center Wing that said although the five engines were needed for takeoff the aircraft could fly on just the outboard engines if push came to shove the port side fuselage carried the pilot mechanic a Gunner and the Navigator the co-pilot another mechanic and a gunner were in the starboard fuselage for a total crew of seven only the pilot had a full set of flight instruments including five throttle levers to control the somewhat excessive number of engines the co-pilot had only a control column curiously control of the radiator flaps was split so that each pilot controlled only those flaps on his side redundancy was thus fairly limited given how hard it was to balance the power from the five engines flying it from the starboard side must have been quite challenging both sides did however have landing gear controls so at least the co-pilot might have a chance to put it down strengthening was added in the wings and fuselage to deal with the additional stresses and strains of glider Towing the center Wing section was just over 40 ft wide in total giving the h111 z a wing span of 116 1/2 FT 1 h111 on its own had a span of 74t 1 1/2 in tip to tip two h111 h's would therefore be 1483 in so in essence each of the inner wings of the combination has lost 16 ft and the combination has gained an extra engine in the process fully loaded it was a 63,000 aircraft so it was big but it's worth saying that a b29 has 141 ft wingspan and it weighed £120,000 on normal takeoff the h111 Z was however comparable to a B17 which had 103 ft span but could lift up to £65,000 at maximum takeoff weight the total fuel capacity of the combination was 2260 Gall which could be increased to 2900 total by adding 460g drop tanks in this configuration it had about 10 hours of endurance a bander reconnaissance version of the concept were also moted in 1943 with production intended for 1944 although neither were built given the shift to a defensive War the h111 Z2 bomber could carry four henel HS 293 anti- ship missiles which were Guided by a missile control system with this load the h111 Zed had a range of 680 Mi at 195 mph maximum bomb load was £ 15,900 it would have needed increased power so the zed 2 would have been fitted with hear tk11 super ch charges onboard Armament in the bom was increased with the addition of 120 mm mg1 15120 cannon in a rotating gun mount on the center section the Z3 reconnaissance version would have done away with all that kit but it would have had additional fuel tanks increasing range to 3,700 Mi stepping back in time to the original aircraft a pair of h111 H6 is we used to make a prototype and it proved broadly successful when it was evaluated by Pilot at rean 10 were ordered from the factory partly because of limited numbers and partly because heavy gliders proved unnecessary during the Airborne assaults that the Germans executed in places like C the h111 Z's operational history was actually quite minimal as well as on the Eastern front and in the Mediterranean they appear to have been used most often in France in 1944 often Turing two smaller gother go 242s rather than a single gigant trials showed the that three gother could be towed if needed the h111 Z was unfortunately rather slow when towing the gigant they were flat out at 137 mph versus a pacy 150 with two gother because of the need to avoid stress on the airframe they were rather unmanufactured seven others were destroyed on the ground in 1944 German Aviation wasn't however done with twins just yet their next attempt was the me 109 Z now being familiar with the h111 Z we can immediately identify that the me 109 Zed was two of the famous BF 109s with the inner Wings removed and replaced by a constant chord Center section the taals were also replaced with a parallel cord single tail plane connecting the two fuselages the aircraft was developed to replace the Aging bf-110 as a heavy fighter with development starting in 1942 it was required for the same reason that the h111 Zed was required namely that German industry was wildly overstretched by 1941 and developing entirely new aircraft for every job was best avoided so mmid modified two BF 109 F4 fuselages the main landing gear attachment points were moved inboard to attach to a strengthened Center Line Keel in each fuser line the outermost main landing gear retracted outboard the inner legs retracted into the new center Wing section a single pilot sat in the PK cockpit and the starboard cockpit was fared over unlike the extraordinarily long-legged twing Mustang the 109 Zed was designed mainly for heavy Firepower although it did enjoy considerable Mission endurance all told it had a span of 43 6 in and was 29 ft long it weighed just over 13,000 empty and 16,000 at full load it was thus considerably smaller than the p82 which weighed more empty than the 109 Z did when fully loaded much of the difference was fuel although the p82 was physically larger by 20 to 25% all told power came from a pair of 1750 horsepower liquid cooled Dame leben's DB 6011 v12s they were anticipated to propel the aircraft to 46 mph and a ceiling of 40,000 ft fir power is in the form of 5 30 mm cannons sources are a little bit vague but I believe that two of these were in the fuselages one firing through each propeller Hub and the other three were in the wing Center section the primary bomber Destroyer version could also carry up to,000 of external ordinance most likely in the form of unguided air to a Rockets a long range bomber version armed with just a pair of 30 mm C cannons and up to a ton of bombs was moted but never pursued to prove the general concept a pair of Clem Ki 35ds were joined by the wing tips to demonstrate that the 109 Z could be piloted from a cockpit located to the side of the center line Construction of a flying prototype with 90% commonality with the donor me 109's thus began in 1943 it was largely completed when the hanger in which it was being built was struck in an RAF night raid on the mes Schmid test center the damage was severe and eventually the entire project was abandoned in favor of putting more resources into the me262 the 109 Zed does however remain a tantalizing what if mes Schmid also proposed a twin version of their 309 follow on piston engine fighter designated 609 again the success of the me262 killed this concept before it got going as well while we're on the subject of failed Nazi twin fuselage Fighters the alternative to The bf19 Zed was the clean sheet Tado AR 530 unsurprisingly this didn't make it off the drawing board despite some theoretical performance advantages the axis weren't done with twins there either in cesto kende Italy the Savia machetti company responded to an Italian Ministry of Aviation requirement for a heavy high performance fighter able to be used as an escort fight a bomber strike and reconnaissance aircraft Savia mati proposed two aircraft the first was a conventional twin boom plane with a central and a cell called the sm91 the other was a twin fuselage variation on their pre-war sm88 designated sm92 caproni aeronautica buram Masa also responded with the ca 380 corsaro which was also a twin fuselage design like the bf19 Z the sm92 had crew on only one side this time on the port two men sat there rather than one though the starboard fuselage was streamlined by removing the cockpit and fairing it over a single horizontal tail connected the two fuselages at the rear the tail wheel retracted into a special pod in the middle of that structure engines were Alpha Romeo ra 1050 RC 58 tones which were license-built V12 Dame Leen 605s and made 1475 horsepower they drove three bladed propellers the engines were somewhat reliable as they were a reboard 601 and the edges of that Design's performance capabilities Armament was Heavy there were two mg1 15120 mm cannons in the center Wing section and another in the port Wing plus a pair of 12.7 mm breeder safat machine guns under each fuselage nose for a total of four of those and another firing to the rear on a remote controll Mount up to 42,000 of bombs could be carried under the center wing and some smaller bombs on the outer wing sections this was a large airplane it was 44 ft long 60 ft in Span it was also heavy weighing just under 20,000 gross and £ 13,000 empty to add to that it was rather underpowered so it was pretty slow top speed in testing was only 382 mph ceiling was 39,000 ft but I can't imagine performance was very good at that altitude range was 12200 M the aircraft made its first flight on no November the 12th 1943 bearing German Insignia it was however flown by Italians although mji was the pilot and his mechanic was Carlo balerini although the aircraft flew well enough in testing it suffered the kind of mishap that seems common to twins on the 17th of March 1944 having flown just 15 hours it was mistaken for a P38 Lightning and attack by a macki c205 flown by a lieutenant mazai effective evasive maneuvers by the pilot prevented the Prototype being shot down but it still suffered engine damage maai was apparently in company with the celebrated Ace Neo tarantola whose call sign was banana he finished the war with 11 claimed kills but why banana did nothing in this engagement isn't clear that said by this time he was pretty much psychologically shot a month later he would suffer severe burns to his legs when he bailed out of his F G55 having been shot down by p-47s anyhow the SM 92s pilot made an emergency landing but in doing so he went off the Runway causing further damage but ultimately saving the aircraft that was however it for the Prototype on December the 27th 1944 the usaaf mounted a bombing raid on the savier machetti factory destroying both the sm92 and the second 91 prototype in the process as I said the caproni ca 380 was also a twin fusal large type that also used the 605 although Capron intended to replace them with the improved 1750 horsepower 603 incidentally caproni had formed with twin fuselages they made around 50 ca3 heavy bombers during the Great War with twin fuselages but also a central and a cell that supplemented the fuselage tractor engines with a pusher I have my rules and I'm sticking to them the 380 was more advanced than the sm92 aerodynamically it had a elliptical wing and the cooling system was inspired from observations of the P38 Lightning ducted annular radiators were arranged in a circular pattern along the fuselage after of the wing where drag due to interactions between the cooling air and the air flow over the airframe could be minimized careful design of the ducts and the outflow allowed enough thrust to be generated to cancel out the remaining cooling drag Armament was also interesting a quad pack of 20 mm cannons were carried under the center Wing in a removable pod the arrangement allowed heavier bomb loads to be carried in lie of the Cannons a breeder machine gun was installed in each outer Wing as a backup unfortunately all of this was too advanced for Italian industry and it never left the drawing board through the h111 Z the Allies were somewhat aware of the unusual twin fuselage nature of the zilling whether this had any influence on their own initiatives to create similar aircraft isn't clear one way or another the best known and most successful twin aircraft started life during 1943 in the always fertile imaginations of the North American aircraft company the problem they were trying to solve was how to provide adequate escort for b29 raids on Japan needing something in short order they mocked up a fighter made from two P-51D Mustang fuselages grafted together with a short connecting structure in which the guns and ammunition were held the twin Mustang was well received by the aircraft but its development took longer than the remaining years of the war to complete although it emerged looking like two Mustangs put together in reality the twin Mustang has little in common with its single fuselage brother for starters the twin Mustang fuselages are nearly 6 feet longer than the single mainly as a result of the need to accommodate more fuel in the rear like the h111 Z each 39 ft long fuselage contained a cockpit but only that of the command pilot on the port side had a full set of flight instruments the starboard co-pilot's cockpit had basic instruments to fly the aircraft but it lacked things like conventional landing gear controls or the ability to use or jettison external stores if the commander was incapacitated then the gear could be blown down using an emergency handle but because the co-pilot would fly for extended periods he did have a full set of engine controls fuel transfer controls deicers and so on in theory the co-pilot's cockpit could also be removed and the canopy fared over using a panel app by North American but I don't think this was ever actually done in practice although it looks a little ungainly performance was excellent maximum speed was 460 mph ceiling was just under 40,000 ft and range was an exceptional 2,200 Mi because of the latter the twin Mustang did see some Service as an escort fighter its main role however was as an interim KN fighter to replace the p61 carrying a radar between the two hulls and converting the co-pilot's it into a pure radar Observer station without flight controls a total of 270 twin Mustangs were produced the majority of these aircraft replaced the very successful Merlin engine of the P-51D with a version of the American built Allison v710 adapted for high altitude flight this was not a successful engine and it wasn't a sensible move even if it did save in royalty payments unreliability of the engines and to a lesser extent The Radars reduced the operational effectiveness of the type throughout its career because I've covered the twin Mustang at length before I'll not repeat a detailed description here suffice to say that the aircraft would have disappeared Into Obscurity were it not for North Korea's invasion of the south in 1950 because the USAF day fighter squadrons deployed in Asia were equipped with the good but short-legged f80 shooting star the task of establishing air superiority largely fell to the twin Mustang it was a large aircraft but the f82 was also quite agile as well as being fast it had a 408t wingspan so although it weighed as much as 25,000 fully loaded at a more realistic combat weight Wing loading was below 50 per square foot the yak 9 or an f-51 had a 40 PB s foot Wing loading but they were also a bit slower combat experience would show that when well flown the twin Mustang was a match for the Soviet fighter in the early months of the war their pilots would shoot down three aircraft and destroy a further 20 on the ground dwindling numbers restricted their operations in subsequent months and as US Air power increased and began operating from bases in South Korea f82 operations declined they were withdrawn in March 1952 having lost 11 aircraft in combat and a further 11 in operational accidents back in Germany in the middle of 1944 yunus inherited the dorier 335 Z longrange reconnaissance program from HL who were brought brought in to assist dorier because they lacked the experience in building such aircraft after meeting with Engineers from dorier and hle Professor hrich hurtle decided that it would be late 1945 before the first prototype of the do 335 Z would be ready having made some initial modifications Professor hurtle decided that he could get the first prototype ready by February 1945 after a few more modifications including new main Wheels length and fuselages and an increase in the center Wing cord and length his aircraft was given the official designation ju 635 the landing gear modifications were quite radical it setup was to consist of a steerable wheel under each fuselage nose the two main Wheels which were fitted with mud guards to protect the rear radiator intakes and a jettisonable fifth wheel located beneath the center Wing which was fitted with a parachute for Recovery based on this design a purchase order for four prototypes and six pre-production aircraft was issued the Ju 635 used two modified do335 fuselages joined by the usual constant cord Center Wing section the outer Wing panels were tapered back and two 1200 L drop tanks could be carried to increase range for Dame leben 603 E1 engines supplied the power one in each forward fuselage pulling and two in each rear fuselage driving a pusher propeller via a long drive shaft fuel was to be carried in 10 internal Wing tanks four in the fuselages and optionally one in each fuselage systems Bay it was a large aircraft with a wingspan of 90 ft and 60t fuselage length it weighed £47,000 no Armament was fitted due to the fact that this was a long-range reconnaissance aircraft and thus all weight was reserved for fuel and speed as designed it would hit 430 mph the Port fusar Bay carried two RV 5030 cameras alternatively One camera and a 66 gallon tank of gm1 nitrous oxide to give a power boost at high altitudes could be carried the starboard Bay contained 5 60 kg marker bombs pilot and radio operator both sat in the port fuselage a second pilot and the Navigator were in the starboard Radars could be carried if required as well wind tunnel testing of scale models in early 1945 proved promising but by this point there was no way that German industry could tool up to make something as sophisticated as a 635 all work was stopped in February although Imperial Japan had initially been interested in the design the excellent range of which would have been useful in the Pacific they didn't take on the project and it died before an actual prototype was constructed only cockpit mockups were ever completed having said all of this I can now come to a highly spurious aircraft that I wouldn't usually include but if I don't include it then it'll be commented on according to one source and I have to stress it's one Source at around the same time that the me 109 Z and the twing Mustang were coming together the designers at supermarine were also playing around with a long ranged escort fighter their concept grafted together two Spitfires to make the mark 99 which was on the drawing board in 1944 it was essentially the same in concept as the twin Mustang but it never made it into the metal after the war however the project was rekindled as the type 1 199 this apparently used two f Mark 21 Spitfires as its basis which is in and of itself a slightly curious decision as the mark 21 was not a great example of the breed it had come out of the need to strengthen and trim the design in order to cope with greater aerodynamic forces generated by the new 2000 horsepower Rolls-Royce Griffin 61 unfortunately the extensive changes to the wing INF fuselage caused the mark 21 to have rather poor flight characteristics it was produced in limited numbers s limited service and the line was abandoned after the war a twin Spitfire based on the mark 21 supposedly flew in 1946 but the Prototype was then abandoned and it disappeared although it's exciting to consider the possibility of such an aircraft I personally consider this tale to be quite unlikely British aircraft of the period and particularly Spitfire variants are very well covered we're therefore aware of the proposed twin engine Spitfires the various float plane Spitfires and other interesting Concepts that a twin fuselage Spitfire was not only proposed but it actually flew and then simply disappeared with only one drawing a doed photograph and one brief testimony as evidence is hard to believe I'll leave you to draw your own conclusions and if you've got some good photos and information about it I'd love to see those after the war there was a lull in Twin fuselage projects with the exception of the twin Mustang unless you wanted unbelievable range it was better to focus all your efforts on making a first generation jet no number of fuselages could make up performance difference the exception to this rule was in the Soviet Union the issue that the Soviets were trying to solve was how to threaten North America with nuclear armor gedon and still give its bomber Cru at least a theoretical chance of living to tell the tale the tu4 bull didn't have the range to get over the pole and return since at this time Stalin was less than trusting of his bomber okb Chiefs some bright SP Mark dreamed up the idea of Simply bolting together two of yosef's favorite us products to make a super long range high altitude bomber the resulting twin bull never made it off the drawing board which is probably for the best as its landing gear track would have been a tidy 160 ft or so range was 7,000 M on paper which would have been more than enough had push come to shove though Starling then promptly died into POV never a fan of the idea quickly got rid of it the next twin fuselage project chronologically was the famous twin urgan of June 1954 this stretches my definition of a combat aircraft as it was intended primarily as a test bed for snk's new large Vulcan or atar 104 engine rather than risk a concurrency problem and develop the engine and the aircraft aerodynamics together it was decided to split the two development lines to develop the engine das's design office in La proposed a variant on their urgan straight-winged Fighter the aircraft would have been made of two urgan fuselages the central part of which would have been lengthened to receive an atar 101 E3 complete with a custom tailpipe as usual the two fuselages were to be joined together by a rectangular Central plane on top of which was the Nel carrying the Vulcan test engine the empesar urgan elements although with 2 and 1/2t extension ions added to increase Wing area that modification made the span 70 ft which given that the uragon was only 41 ft long would have made some interesting handling characteristics the front landing gear would have been the original one but the main gear was the same as that on the rough field capable Baragon featuring double Wheels this was all very clever in the technically sensible but practically mad way that French engineering tended to Veer since the atar 104 was in development Hell by the summer of 19 54 in September the twin urgan was cancelled just as scale models of it were being prepared for wind tunnel testing no military variance seems to have ever been planned and the intended performance figures are unclear I find all of this a bit of a shame the urgan was an excessively conventional Fighter for the time bolting two of them together to make a madap twin version is almost laughably contrary to das's original ethos the twin urgan was itself undoubtedly inspired by the earliest successful twinning of two fuger cm8 gliders to create a test bed for turbo mecer engines the resulted cm88 jumo first flew in March 1951 with each fuselage carrying its own engine it was used to test a lineup of small jet engines that find their way into trainers in the 1950s cm88 was typically interesting its most distinctive feature is the W tail made by simply connecting the inner taale surfaces of the two gliders together it was a stately aircraft capable of barely 200 mph which is just as well because it was of lightweight wood and metal construction there were controls in both cockpits but the primary pilot sat on the left side only one was built but at least it unlike many of the aircraft I've discussed so far both made it into flight and fulfilled its design purpose the last attempt at a twin fuselage jet fighter project came from the Bulgarian designer Demetria tanang in the early 1960 s Bulgaria had a large Fleet of now obsolete Mig 15s in its inventory and was not high on the priority list to get more modern types many of the only had minimal flying hours it seemed a shame to waste them and yet their lack of ordinance carrying ability made them of limited tactical value so aanai proposed to convert into dual fuselage twin engine fighter bombers capable of carrying more than 3,000 of Bombs Over quite a reasonable range sadly this propos osal too came to nothing which might have been the right answer as the fuselages look rather too close together given what we've seen in other aircraft tenoso did successfully design a modification that converted some of the Surplus Mig 15s into trainers though so some use was made of the aircraft to be totally honest at this point I've probably spent far too long down this particular Rabbit Hole there was a period of time before the jet age when speeds were more forgiving of aerodynamic imperfections that the aircraft offered some interesting and useful performance improvements looking solely at those aircraft that flew a second world war eara twin gave between 5 and 20% more top speed and between 35 and 50% better endurance at the cost of larger size and somewhat reduced maneuverability in hindsight had Air Forces pursued twins rather than clean sheet heavy Fighters then that type of aircraft might have been more successful the issue with the clean sheet was that designers tended to start with too much structure a central fuselage and two engines and too many medium bomber features like a rear Gunner this made the resulting aircraft too heavy and too vulnerable to single place single motor Fighters a twin is an industrial compromise that forces a military one and therefore it does away with those fripperies with useful results anyhow jet experiments demonstrated that there was little value in continuing with the concept after the swep wi was introduced although still useful for the occasional flight of fancy the twin usage is noal