Beardmore Inflexible

1st Flight 1928

Military Users- Royal Air Force.

Beardmore Inflexible

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.

Beardmore Inflexible

The aircraft was built in sections at Dalmuir between 1925 and 1927 and these were sent by sea to Felixstowe and from there delivered by road to the Aeroplane & Armament Experimental Establishment at Martlesham Heath Airfield where it first flew on 5 March 1928, appearing at the Hendon RAF Display later in the year.

The aircraft was structurally advanced for its time and had good flying qualities.

Beardmore Inflexible

It was also a very large aircraft for the time, having a wingspan of 157 feet (48 m) – around 16 feet (4.9 m) greater than the Boeing B-29 Superfortress heavy bomber of World War II.

However, with an all up weight of 37,000 pounds (17,000 kg).

Beardmore Inflexible

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.

Beardmore Inflexible


Length: 75 ft 6 in (23.02 m)

Wingspan: 157 ft 6 in (48.05 m)

Height: 21 ft 2 in (6.45 m)

Wing area: 1,967 sq ft (182.8 m2)

Empty weight: 24,301 lb (11,022 kg)

Max takeoff weight: 37,000 lb (16,783 kg)

Power plant: 3 × Rolls-Royce Condor II V12 piston engine, 650 hp (485 kW) each


Maximum speed: 109 mph (175 km/h, 95 kn)

Beardmore Inflexible


Beardmore, The history of a Scottish industrial giant-John R Hume.

Beardmore Aviation, The Story of a Scottish Industrial Giant’s Aviation Activities-Charles Edward Mackay.


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