Beardmore Inflexible | An Anglo-German Giant

out of all the weird giant aircraft built in the 1920s and 1930s the beard more inflexible is perhaps one of the most obscure at least in terms of readily available source material the beard more inflexible also known as the rawbach 6 can trace its origins back to the end of world war one adolf karl rorbuck had worked for zeppelin during the war though famous for their giant airships the company was already looking at diversifying their aircraft portfolio as early as 1913 and were expanding into the design of heavier-than-air aircraft during the war rohrbach had been involved with the design work of the massive airplane bombers and following world war one he designed the zeppelin starkin e420 which was an all-metal four-engine airliner unfortunately this aircraft was to be scrapped in 1922 as it violated the terms of the treaty of versailles following this roebuck founded at the roebuck metal aircraft company and began designing even more aircraft carefully evading at the treaty of versailles by having the aircraft designed in germany but built in copenhagen around the same time as this the british air ministry was beginning to recognize the importance of all metal aircraft especially for larger designs they issued a specification that called for the design of a large all-metal experimental transport a contract was soon awarded to william beardmorton company which was based in scotland beardmore had built aircraft under licence during world war one but they were primarily involved with shipbuilding locomotive and engine construction as they lacked aircraft design expertise themselves beardmore was tasked to work with rohrbach on the design of this new experimental aircraft beardmore would outline and dictate the aircraft's specifications based on the air ministry's specification and roebuck would then work on the main design once this was completed it was licensed to beard more in 1924 and construction of the aircraft began in what was rapidly becoming practice especially with large aircraft designs the aircraft was tested in the royal aircraft establishment's wind tunnel at farnborough the tests proved very promising and this was down to the fact that despite its large size the inflexible was of a fairly simple and conventional design construction of the inflexible was not exactly a rapid affair however hampered by material shortages and registration delays the aircraft was not completed until mid-1927 and then it had to be packed down and transported for testing this presented its own issues due to its vast size the aircraft was disassembled and transported by sea from glasgow to ipswich however once it got there further transport was delayed once again as it was found that they would need to build a specialized vehicle with steerable axles to get the aircraft from ipswich to martelshim heath airfield once it finally arrived another problem arose as it was realised that the inflexible's wingspan was larger than any hanger opening that they had available eventually a series of wheeled trolleys were built that allowed the aircraft to be stored in the hangar sideways in its final assembled state the inflexible made for an impressive sight it was a shoulder wing tri-motor monoplane of all-metal construction a very futuristic design for 1927. it had a length of just over 23 meters a wingspan of 48 meters greater than that of a b-29 superfortress and a maximum height of six and a half meters like many early monoplanes the inflexible's wings were rather box-like the center-wing section was formed by a wing box that was bolted onto the fuselage attached to each outer section of the central wing were the outer wing sections which were supported by wing spars a cable was used to keep the huge wings in tension during flight this cable ran from the weir ring spar to the lower fuselage the curious wingtips look like somebody put the final section of the wing through a photocopier set to 25 percent but in fact they are balance horns that we used to reduce control surface flutter a suitable precaution as the inflexibles ailerons spanned the outer half of each wing's trailing edge due to their immense size the wings were also designed to carry the entirety of the aircraft's fuel load 2482 liters of fuel split between four large wing tanks the wings were clad in the same metal that was used to make the rest of the aircraft which was geralamin a strong lightweight alloy of aluminium that is increased in strength by the incorporation of copper manganese and magnesium the fuselage was rectangular in shape and consisted of two sections that were bolted together that made for easy maintenance disassembly and transport at the rear of this fuselage were the large vertical and horizontal stabilizers to help better control its movement a servo tab trailed behind the rudder and the aircraft's elevator spanned the entire width of the horizontal stabilizer powering the inflexible were a trio of 35 liter 12-cylinder rolls-royce condor 2 engines which had an output of 670 horsepower each like everything else about the inflexible thus far these engines were big weighing 628 kilos each and they drove a large two-blade fixed pitch propeller the radiator for the nose engine was located below the fuselage and the other two engines had their radiators mounted between the engine nacelle and the fuselage itself the inflexible was a heavy beast it had an empty weight of 11.3 tonnes and a maximum weight of 16.7 tonnes this heavy load was supported by two huge main wheels and a steerable tail wheel the wheels themselves were a bit of an innovation specifically developed by dunlop and with a diameter of 2.2 meters they were some of the largest wheels fitted to an aircraft at the time originally they had been designed as the more traditional wireframe spoke wheels that were common on many aircraft at this time but the inflexible's heavy weight buckled them and a new sturdier pair were made from aluminium and steel each wheel was supported by a large shock-absorbing strut that extended from the rear of the engine nasal with the wheel itself being supported by an a-frame mounted to the lower fuselage next to the wheels was another innovation necessitated by the sheer size of the aircraft a hydraulic braking system designed by a young and relatively unknown engineer by the name of kurt tank who would go on to design such aircraft as the focke-wulf 190. ground testing of the inflexible began at the beginning of 1928 but before its first flight it was decided to extend the length of the existing martelshim heath airfield by another 400 yards as there were doubts that such a large heavy aircraft could take off on the current airstrip it would be an unnecessary precaution however as the aircraft took to the skies for the first time on the 5th of march 1928 within the limits of the original airfield length it was flown by test pilot jack knox and he flew the inflexible for around 15 minutes taking it up to an altitude of 1014 feet he reported that the aircraft had been stable and easy to control although it did feel a bit sluggish follow-up testing confirmed that the aircraft was indeed underpowered only reaching a maximum speed of 175 kilometers an hour this prompted the discussion for a replacement of its engines though this was never to happen the low power also meant that the inflexible handled poorly at slow speeds or in less than ideal weather and that was something that hurt the raf's interest in the project during the course of 1928 the inflexible made a few different public appearances and flights though the pilot was strictly advised not to attempt any kind of aerobatics despite capturing public interest with its all-metal frame and innovative features the aircraft failed to secure any production contracts and by 1929 its flying days were over beardmore was already having financial struggles after world war one and the failure of the inflexible to secure contracts along with various other misfortunes led them to closing their aircraft development branch by the end of 1929 the inflexible had proven the feasibility of all metal designed aircraft but the wall street crash and subsequent great depression put a stop over all thoughts of modernizing british aircraft until the mid-1930s the inflexible was used for static testing in mardlesham heath in 1930 the engines were removed and placed into storage and after the static tests were completed the wings fuselage and various components were used for corrosion testing which basically gave the people in charge a fun excuse to let the airframe sit outside in the british drizzle and slowly rot away the remains of the aircraft were scrapped in 1931 with the only surviving item of the inflexible being one of its giant landing wheels which can now be found on display in the science museum in london i mentioned at the start of the video that there was a small amount of source material for this particular aircraft my two primary references for this were a book called beardmore aviation 1913-1930 by charles mckay and british prototype aircraft by ray stewart event i think i was able to borrow a copy of the former and i own a copy of the latter just in case you wanted to know where i found the information [Music] [Music] you

Channel: Rex's Hangar

Views: 252,754

Keywords: Beardmore Inflexible, rc plane, beardmore, england, germany, aircraft, military, history, inflexible, dornier, Rohrbach, monoplane, aviation, aircraft development, bomber, 1920s aircraft, WW1, Zeppelin-Staaken, British Air Ministry, raf, RoVI, rohrbach vi, giant plane, giant monoplane, historical aircraft, raf farnborough, wind tunnel, William Beardmore & Company, Martlesham Heath, air demonstration, aviation development

Id: l9Qz6c38sGk

Length: 9min 47sec (587 seconds)

Published: Sat Jan 01 2022

Reddit Comments

[u/Nissedasapewt]

I enjoyed the video. Good to see the background for how the aircraft came about and nice to have the sources explained. Thank you for posting.

[u/particlegun]

Inflexible flying including a rather concerning landing.

[u/Imnomaly]

I've read it as Bearmode and it fits

[u/dartmaster666]

These post really suck you know. They usually take a while to get to the actual plane the video is about.