In 1964 the Tripartite Kestrel Evaluation Squadron, or TES, was formed in the UK by the governments of the United States, West Germany, and Britain. The purpose of the TES was to perform operational trials with the Hawker P.1127 Kestrel.
Each nation provided personnel and pilots for the TES and West Germany was represented by Colonel Gerhard Barkhorn, who was the second-highest scoring ace in the Luftwaffe during World War 2 with 301 victories. The Germans participated in the TES to forward their own knowledge base with their own V/STOL project, the VAK.191. On one test flight, Barkhorn cut the throttle too early while in vertical landing mode and the Kestrel dropped quickly and destroyed the undercarriage. As Col. Barkhorn walked away from the crash-landing, he kicked the aircraft out of frustration and declared that the wrecked Kestrel was the "302nd Allied aircraft" he had destroyed.
Source: BAe/McDonnell Douglas Harrier by Andy Evans. The Crowood Press Ltd, 1998 (Crowood Aviation Series), p11-13.