Rolls-Royce Thrust Measuring Rig

The Rolls-Royce Thrust Measuring Rig (TMR), was a pioneering vertical take-off and landing (VTOL) aircraft developed by Rolls-Royce in the 1950s. It has the distinction of being "the first jet-lift aircraft to fly anywhere in the world".

The design of the TMR is unique. It was powered by a pair of Nene turbojet engines, which were mounted back-to-back horizontally within a steel framework; in turn, this framework was raised upon four legs fitted with castors for wheels. The TMR lacked any lifting surfaces, such as wings; instead, lift was generated purely by the thrust being directed downwards. Due to its unconventional appearance, it was understandably nicknamed the Flying Bedstead.

The TMR had been envisioned specifically for conducting research, specifically to explore the potential applications of then-newly developed jet propulsion towards carrying out vertical flights. First flying in August 1954, extensive studies were conducted during a series of test flights into how stabilisation could be performed during the aircraft's hover. It contributed to a greater understanding of the level of power and appropriate manners of stabilisation involved in a VTOL aircraft, as well as proving the feasibility of the concept in general.