Question: The Walter HWK 109-509 powered the first piloted aircraft of any type to exceed how many MPH in level flight?
Sentence (from "Messerschmitt Me 163 Komet"): German test pilot Heini Dittmar in early July 1944 reached 1130 km/h , an unofficial flight airspeed record unmatched by turbojet-powered aircraft for almost a decade.
Relevant evidence: No