William Beardmore and Company had acquired a licence for the use of the Rohrbach principle for stressed-skin construction. Using these principles and drawings supplied by Rohrbach for the RoVI, the Beardmore company designed, what was then a massive all-metal three-engined transport, the Beardmore Inflexible.
The aircraft (Serial Number J7557) was built at Dalmuir between 1925 and 1927 and was delivered by road to the Aeroplane & Armament Experimental Establishment (A&AEE) at Martlesham Heath Airfield where it first flew on 5 March 1928,[2] appearing at the Hendon RAF Display later in the year. The aircraft was structurally advanced for its time and had good flying qualities. It was also a very large aircraft for the time, having a wingspan around 16 feet (4.9 m) greater than the Boeing B-29 Superfortress heavy bomber of World War II. However, it suffered from being underpowered and, with no interest in production, the aircraft was dismantled at Martlesham Heath in 1930. It was then used to investigate the effects of corrosion on light-alloy stressed skin structures
From the Aviastar Site
"My father was an engine fitter on the Inflexible (fresh out of RAF apprentice school Halton) and had this to say about this aircraft:
“ Powered by 3 Rolls Royce Condor’s and with a wingspan of 158 ft it was the biggest aircraft of it’s day. However the “Boffins” and “Know-alls” of the time decided that it would never fly and if it did the wings would fold up. Therefore before being allowed to make the attempt it had to be fitted with support cables from the wing roots to nearly the wingtips. I have a photograph of the Inflexible where these can just be seen. They also decided that it would need more than the length of the existing airfield at Martlesham Heath to take off. With this in mind an extra 400 yards of heath was cleared for the initial flight. Most of the population of Ipswich and the surrounding villages turned out to watch the event. As it happened the extra 400 yards was not nearly needed and the Inflexible took off well before the end of the existing runway, no strain was evident on the cables and according to those on board, the flight was uneventful and the aircraft flew well. It was never allowed to fly without the cables, which completely ruined any chance of the Inflexible being termed a proper cantilever wing. The cables were as thick as those used to moor ships”.
Type Night bomber
Engine 3 Rolls-Royce Condor IIIa with 2-bladed wooden propellers
Dimensions Length 22.9 m, span 47.9 m, wingarea 182.8 m2, aspect ratio 12.6
Weights Empty 11022 kg, load 5758 kg, flying weight 16780 kg
Performance Max. speed 180 km/h at sea level, cruising speed 160 km/h, landing speed 102 km/h, climb 12 min. to 1000 m, service ceiling 3800 m, range 1600 km
Type Werk.Nr Registration History
J 7557 Built by William Beardmore & Co, drawings provide from Rohrbach. First flight 5th of March 1928. After testing it was dismantled in 1930. .This aircraft was built purely for research. It was built by Beardmore at Dalmuir under great secrecy. In the air it was described as a pilot's aeroplane. In the company records it's referred to as the BERO BE for Beardmore and RO for Rohrbach. The pilots were Noakes and De Haga Haig and both were ordered never to do aerobatics in public. It was so strong that you could see the fuselage wrinkle and the young airmen used to run along the wings and fuselage. When testing was completed the fuselage was broken for paint tests, were used for corrosion tests then it  disappeared by 1933. It had the biggest wheels in a pre war aircraft.