The Hawker P.1127 and Hawker Siddeley Kestrel were British experimental V/STOL aircraft that established the vector-thrust technology and flight experience leading to the operational Harrier. The P.1127 achieved tethered and untethered hover and transition testing from 1960, while Kestrel development aircraft supported the 1965 Tripartite Evaluation Squadron; the Harrier family remains a separate operational lineage.
Alerts for directly linked future launches and major activity.