30 YEARS AGO
SEPTEMBER 7, 1978
Pratt & Whitney Aircraft has been selected to provide the engines for Boeing’s new generation of wide-body commercial jetliners, the medium-range 200-passenger 767. Two P&WA JT9D-7R high-bypass turbofan engines, developing 44,300 lb of takeoff thrust, will be installed on each 767 when it enters service in mid-1982. The JT9D-7R is the latest version of the JT9D engine, and is a rerated version of the JT9D-7, which produces 46,300lb of takeoff thrust and has been in service since 1971. The 7R’s lower thrust permits use of less-complex turbine hardware and retains a maximum number of parts common to existing JT9D-7 engines.
50 YEARS AGO
SEPTEMBER 4, 1958
More speed on less power is the goal of a research program on underwater cargo vessels. A simple principle is involved: Submerged hulls don’t generate waves, thus have much less drag than surface vehicles. This jet-propelled model, conceived by Aerojet-General Corp. for the U. S. Maritime Commission, is controlled from a gondola atop a 100ft-tall strut. Air for the powerplant is drawn through the strut, snorkel-fashion. Underway, the ship operates with excess positive buoyancy. A triaxial-control system provides steering, longitudinal and transverse stabilization, and hydrodynamic control needed to force the ship to its proper operating depth. In effect, the craft flies underwater. The ultimate source for driving the jet-propulsion pumps is a nuclear powerplant.