What milestones did the P.1127 achieve?

Short answer

The XP831 prototype made its first tethered flight on 21 October 1960 at Dunsfold, its first free hover on 19 November 1960, its first conventional flight on 13 February 1961, and in June the first transition from hover to forward flight.

Published: November 1, 2026 · Updated: November 1, 2026 · Edited by Above Ten Thousand · Editorial policy

Takeoff of a Hawker Siddeley Harrier GR 1

First flights at Dunsfold

On 21 October 1960, XP831 made the programme's first tethered flight, at Dunsfold. On 19 November 1960, the same aircraft achieved the first free hover flight, with no restraints. On 13 February 1961, XP831 made its first conventional flight, piloted by Bill Bedford and lasting 22 minutes. In June, XP831 reached another programme milestone by performing the first transition from vertical hover to horizontal flight. On 7 July 1961, the second prototype, XP836, made its first conventional take-off.

The Pegasus engine behind the prototype

The original concept behind the engine, named Pegasus, came from Michel Wibault, a French aeronautical consultant, who had the idea of using vectored thrust for vertical take-off aircraft.