The American order for the Harrier was a tremendous boost to the Kingston-based team, not only providing greater security for the Harrier programme but also helping to gain greater acceptance for the whole V/STOL concept. By early 1969 the full range of flight tests necessary for CA release to the RAF were complete, with the first five production aircraft joining the development batch machine's in trials. The Harrier was already showing that it had many commendable qualities over and above its V/STOL abilities. It was nearly impossible to spin. It was already demonstrably reliable and easy to maintain. And it was possibly the most potent single-seat strike aircraft in the world. All of these helped to reduce the levels of hostility that had previously existed from some elements of the RAF as thay began to get to grips with the aircraft themselves.

Harrier GR.1 taking off from an unprepared site.	Harrier GR.1 in flight over mountainous terrain.

On 1 January the RAF established the Harrier Conversion Team at Wittering, although it spent the first few months of the year at Dunsfold training the initial group of Harrier pilots. All training at this stage was on single-seat Harriers - the first two-seat aircraft did not fly until April 1969 and the first delivery to the RAF was not until July 1970 - after a preliminary helicopter course to experience vertical flight. The HCT officially began operations on 1 April 1969, with the main effort over the summer being aimed at training the pilots of the first operational squadron, No. 1 Squadron RAF (motto In Omnibus Princeps - in all things first). This squadron was re-formed on 1 October, being declared to the RAF order on battle on 1 January 1970, thereby becoming the first front-line, jet V/STOL unit in the world. In the midst of the training two aircraft took part in the Trans-Atlantic Air Race of May 1969, being declared winners of the westbound leg from London to Manhattan.

Almost uniquely for a post-war British combat aircraft, the Harrier programme was on time and on cost - a feat that aroused comment in Parliament! After more than twelve years of work at Kingston and Bristol, after political and military indecision, the P.1127 series had matured as a combat aircraft. Although the methods of operation to be used in service and the future development of the aircraft were unclear, the success of the programme was already proven. The Harrier had arrived.