News and Views Available to Purchase

Flight tests with the Boeing 747‐300 are proving that the new extended upper deck jetliner matches or betters performance shown in the original specifications. With more than 150 hours flown by the initial airplane in the series — a “combi” model for Swissair—tests show that the most efficient high speed cruise is Mach .85 to .86. This compares with .85 for the 747SP which has had a highest cruise speed of any subsonic transport flying.