VTOL testbed prototypes

"It was an ungainly-looking contraption" - unknown commentator on the LLRV

"Ungainly" describes them well. The term "flying bedstead" was used to describe two test vehicles, the first being a Rolls-Royce beast used to establish the engineering requirements for Vertical Take-Off and Landing aircraft. This prototype's first free flight was on 3rd August 1954. The second was a NASA testbed for the Apollo Lunar Lander, which first flew on 30th October 1964.

The British Take Flight

I became familiar with the British Flying Bedstead when I lived in Hucknall, where Rolls-Royce had a test facility. Just down the road from the airfield was a pub named after the machine, and there's a painting on the wall of the machine in flight. A quick chat with the barkeep was enough to satisfy my curiosity for then. Since then I have visited the National Science Museum in London to actually see it in the flesh. Well, I say flesh. It's well named, a mass of tubes and pipes containing two jet engines, a seat and no lifting surfaces like wings, and resembles some dreadful alien robot insect.

Officially designated the Thrust Measuring Rig, this perilously-fragile thing was nonetheless a mighty machine, as it paved the way for the development of the Short SC.1, the first fixed-wing VTOL aircraft in the UK. Later technology and development resulted in the better-known and highly successful Harrier series of aircraft.

Two TMRs were built and tested in Hucknall. The first flight took place on 3rd July 1953, and was a tethered flight, a secured gantry being used to ensure that it did not fly too far from the ground, and to provide a safe landing in the event of engine shutdown. The first truly free flight was a month later, piloted by Rolls-Royce's Rolls-Royce's chief test pilot Ronald Shepherd.

The power was provided by two "Nene" jet engines mounted in line. Power was bled off from these engines and routed to control nozzles and controlled by the pilot, who sat atop the whole edifice. The whole contraption looks unwieldy, and watching the video of it in flight, I'm inclined to say that the pilot earned his OBE in spades. I'll spare you the scary technical details, which are given in the references below. Suffice to say that the whole thing looked like it was designed by Heath Robinson, and I would not have touched it with a bargepole.

Dangerous to fly? Yes. The second rig first flew (tethered) on 17th October 1955, and eventually killed its pilot two years later, 28th November 1957. I was eighteen months old.

America Takes Off With Rockets

Just a decade later, the Americans were planning to fly to the Moon, developed the Apollo Program, and of course, they needed to develop and test the technology to land there and take off.

The US testbed was very different from the British one, as it used the single, centrally-mounted jet engine only to cancel out 5/6 of the weight of the aircraft, to enable a simulation of the process of control under lunar gravity.

In fact there were two variants, the Lunar Landing Research Vehicle (LLRV) and the Lunar Landing Training Vehicle (LLTV). The LLRV was used to study the techniques of piloting a landing craft in low gravity, and the LLTV used to train the astronauts themselves. In each case, jet engines carried most of the weight of the craft, and hydrogen peroxide rockets were used to control and manoeuvre it.

Bell Aerosystems designed and built the LLRVs, which were delivered to the Dryden Flight Research Center at Edwards Air Force Base. On the 30th of October 1964, the first flight took place. The pilot, Joe Walker flew the Bedstead three times to about ten feet, for a total flight time of just under a minute. By the middle of 1966, NASA had ordered three LLTVs; delivery began in December, and the astronaut training program began in earnest.

The flights were on the whole successful, though famously, Neil Armstrong had to eject on one training flight, seconds before the vehicle crashed. According to Wikipedia, however, three of the five Bedsteads crashed, though all the pilots survived.

One LLRV is on display at Dryden Air Force Base, and the sole surviving LLTV is currently at the Johnson Space Center.

Each in their own way, these monstrous-looking aircraft changed how we viewed the world. Hucknall's prototypes led to a highly-successful military aircraft, and NASA obviously landed on the Moon. Engineers and test pilots alike, I salute you.

Video of the British Flying Bedstead
Technical report
LLTV footage

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