The Giant Airliner With Cabins In Its Wings | Junkers G38 [Aircraft Overview #19]

the junkers g38 was a striking site when first flown in 1929 it was perhaps the pinnacle of blended wing aircraft design in the interwar period at least as far as success goes it was made during a time when some aircraft designers predicted that blended wing or indeed complete flying wing aircraft would be the future with many passengers housed in these large wings as opposed to a fuselage in 1929 this was not a new concept for hugo junkers 20 years previously he had applied for a patent for a thick profile hollow wing design that could be

used as a large commercial aircraft way back in 1909 the standard design for aircraft at the time could be summarized as a flying crate as the old saying goes most aircraft were thin winged biplanes that relied on a massive wires and struts which whilst effective was not the most aerodynamic of designs junckers rejected this way of thinking and wanted to bring forward the concept of a large cantilever metal wing which as a result of its aerodynamically functional design and thickness would provide an optimal ratio of lift drag and practicability the first world war allowed yonkers

to partially realize his idea of an internally structured aircraft with all metal wings removing the need for obstructive wires and struts but he was limited in his designs by military specifications after the war he now had the experience and the manufacturing facilities available to realize his dream of a large commercial aircraft but this time he was limited by the treaty of versailles in 1920 he began development work on the junkers jg1 which was a four engine or metal transport aircraft construction of a prototype began in 1921 with the outer wing and rear parts of the

fuselage being completed however when the allied supervisory board inspected the factory they found this prototype during their investigations and they demanded work to be stopped and the aircraft scrapped undeterred hugo yonkers continued to drop designs during the 1920s but it would not be until the end of the decade when he would make another serious attempt which would result in the g38 working in collaboration with design engineer ernst zindle in 1927 design work began on project g40 which was for a postal seaplane that could perform transatlantic flights junckers also developed a land plane variant dubbed the

g38 and although the german navy was more interested in the seaplane junckers preferred the g38 as he believed it offered more versatility and he was able to secure funding from the air ministry for its construction from conception to completion work on the prototype took just over two years and in november of 1929 the first aircraft identified as d2000 rolled out of juncker's desal plant for its maiden flight when it took to the skies on the 6th of november 1929 the g38 was the largest land plane in the world the dominating aspect of the aircraft was

of course the huge cantilevered wing it had a wingspan of 44 meters which puts it slightly wider than that of a b-29 superfortress it was built on a series of tubular frames and struts that were bolted together and attached directly to the fuselage to make production maintenance and transportation easier the g38 wing was divided into a central section two intermediate sections and two outer sections covering the structure was the classic stressed and corrugated der aluminium sheets that were the hallmark of many all-metal aircraft built in germany at the time not only did this metal provide

strong and effective protection but it also served to absorb torsional motion exerted on the wing not only was the wing broad but it was also incredibly thick at the route where it met the fuselage it had a height of 1.9 meters this is because it was not just designed as a lifting surface but as a functioning section of the aircraft's internal structure much like the russian kalinin k7 which was covered in an earlier video the front inner sections of the g38 wing was designed to house people and equipment at the front immediately adjacent to the

fuselage and accessed via a passageway were a pair of passenger cabins which offered commanding views through a series of curved windows hopefully it came with a warning to passengers who suffered from vertigo or fear of heights as it also gave you a pretty good view of what was below the aircraft as well as in front of it further outboard from this cabin was the intermediate sections of the wing that mounted the engines the forward portion of each section housing one engine each these consisted of two junkers l55b12 and two l8 inline six engines the larger

engines were mounted as the inward pair and the smaller as the outward pair together they provided the g38 with 1971 horsepower with the more powerful engines driving four blade propellers and the smaller ones are driving two blade propellers this gave the g38 a maximum speed of 225 kilometers an hour and a cruising speed of 180 kilometers an hour not only did this section of the massive wing house the engines but it also housed them in what could be termed as the aircraft equivalent of a ship's engine room access was granted via a maintenance corridor that

carried on behind the wing passenger cabins and their brelvan passageway and this allowed engine work to be carried out during flight certainly not something a lot of aircraft then or now could boast the corridor ran through most of the wing itself and allowed it to be accessible for an inspection almost up to the very wing tips if the engineers were okay with a tight crawl behind the passenger and engine rooms that were on the leading edge of the wing separated by a double firewall and a lot of metal there was the main fuel compartments these

consisted of two rows of fuel tanks with a passageway between them for inspection inward of this and again behind a double firewall were the storage cabins that contained the requisite luggage and cargo of the passengers and crew this being accessed by the fuselage there was also another luggage and freight holder located on the underside of the fuselage like in more traditional commercial aircraft but the thick wings allowed the space to be reduced for better overall cabin space the fuselage itself like the wing was constructed from tubular struts and girders are covered with an all-metal skin

the pilots and co-pilots enjoyed an elevated position in a comfortable cabin just above the nose in front and slightly below them was a navigation room that also helped two passenger seats right up in the front of the nose for those who were feeling extra adventurous behind the cockpit was the chief mechanics post from which the whole power plant and fuel systems can be controlled behind this was the crew cabin in steward's room where meals and drinks would be prepared and adjacent to this room was a small lavatory further behind this there were two more spacious

passionate cabins and a smoking cabin the passenger accommodation was considered to be very luxurious and it was intended to compete with the standards found aboard the zeppelins which were at the time the pride of german commercial aviation like many other yonkers aircraft of the time the g38 featured control surfaces that went along the full span of the trailing edge of the wing they were split into two sections this allowed them to be operated as flaps on the intersection and ailerons on the outer section the tail control surfaces were arranged in a biplane style configuration with

three vertical rudders this was done in response to the consideration of drag if a single large rudder was used the drag force of the tail wing would have been too great to be manually counted all of the control surfaces were dynamically balanced to reduce flutter and reports from the test flight praised the g38 for its easily handling characteristics the controls of the g38 supposedly felt no more difficult than those of the much smaller junkers f13 and g31 which said quite a lot for such a bulky aircraft speaking of bulk the g38 with its all-metal design

thick wings and four engines weighed quite a bit when it was completed at least for the standards of the time it had an empty weight of 13 tons and a maximum takeoff weight of 21 tonnes this weight was supported by a main landing gear arrangement of four large wheels that were set in tandem pairs for improved comfort and ground handling these wheels pivoted on the horizontal plane and were kept in place by a series of springs the landing gear was in a fixed spattered arrangement with shock absorbers built into the vertical frame originally this landing

gear was covered by an aerodynamic fairing but it was at some point removed to save weight and then at another point put back on for the sake of style this seems to go back and forth several times during the 1930s which makes dating any unknown photographs a bit of a pain after its maiden flight the g38 was purchased by the air ministry with the intention of flying it with lufthansa it was then put through a series of tests and demonstration flights which gathered much attention on the 30th of november 1930 test pilots zimmerman and sninzinger

set several world records for speed and altitude whilst carrying a 5-ton payload the flight tests concluded with a round trip around europe which did much to further stoke enthusiasm for yonkers new aircraft and then it was officially delivered to tour lufthansa it then began to run a commercial route between london and berlin almost immediately after it began to fly this route however the decision was made to modify the g38 the recent press tours had so increased demand for the aircraft that a passenger capacity of just 13 was considered ludicrous the engines were upgraded going up

to four l88 to v12s which upped the power from 1971 horsepower to 3100 and all of them now drove four blade propellers the aircraft itself was retrofitted to expand the passenger cabins which increased carrying capacity to allow for up to 30 passengers and their cargo this refit was completed in the summer of 1932 and the aircraft took to the skies once more lufthansa also commissioned the construction of a second aircraft which would be given the designation at d2500 from the outset it was designed with the lessons learned from the first prototype it was built with

a full two-deck fuselage and had its wing cabins expanded to allow for a total passenger capacity of 34. this new aircraft also had the added advantage of giving most passengers in the central fuselage a view of the outside world something that had been missing from the first prototype this aircraft entered service around the same time that the first finished its refit and together they both went into commercial service the g38s soon earned a very strong reputation for luxury and comfort passengers were allowed to move about freely during flight and were catered for by well-trained staff

though their passenger capacity was still somewhat small compared to their impressive scale the aircraft quickly became the pride of lufthansa and german aviation in 1933 the d2500 was given the name marshall hindenburg in honour of then-president hindenburg in 1934 both planes went back for another overhaul this time replacing all of their engines with inline six-cylinder jimo fours giving a new total power output of 4023 horsepower the aircraft were also redesignated the first being g38a and the second g38e unfortunately for the g38a it would not survive past 1936. it crashed during takeoff during a workshop flight

at de sao the result of incorrectly connected cables the pilot survived but the extensive damage wrote off the aircraft it could actually be repairable however the cost of repairing it versus the gain from repairing it was not deemed worthy as the aircraft were already becoming somewhat obsolete by the mid to late 1930s compared to other more larger commercial aircraft that were coming on the field both in germany and overseas the g38e would continue to fly commercial routes for lufthansa until the start of world war ii then it would be repainted in wartime camouflage and used

as a military transport it worked regularly during the military campaign in greece as a long-range transport aircraft for troops and supplies but on may 17 1941 it was also destroyed during a raid by british bombers there had been thoughts of a militarized version of the g38 for use with the luftwaffe in fact junkers had tasked itself to design such an aircraft under the designation k-51 but it was never built at least not in germany as early as 1928 japan had shown interest in the g38 design and were indeed the first to approach yonkers about converting

the g38 for use as a bomber younkers licensed the design out to mitsubishi in april of 1930 and sent a team over to japan to overseas and support further development this was developed into the type 92 also known as the k20 mitsubishi manufactured six of these between 1933 and 1935. they were powered by four jumo 204 engines had a top speed of 200 kilometers an hour and could carry up to five tons of bombs in addition to this they were also well defended for a bomber of this time mounting five machine guns in various positions

and a 20 millimeter dorsal cannon as well when first operated they were the largest offensive aircraft fielded by japan and was shrouded in secrecy but by the height of the second world war they were hopelessly obsolete and were only ever used as transports sadly none of these aircraft survived today having all been destroyed in one form or another usually involving explosions but like the italian caproni 60 they were recently immortalized in the studio ghibli film the wind rises [Music] [Music] you