- May 26, 2006
- Reaction score
from NASA archive;
from NASA archive;
Lee said:I make a supposition: The consensus amongst SST design teams in the 60's was that the plane would be designed with engines sized for cruise speeds only. Until then, subsonic jets had engines sized for takeoff and then the throttle was lowered to conserve fuel at ~35,000 ft.
See what I mean? One only needs modest engines and a slower rate of climb to get to 55,000-75,000 ft with an SST.
High pressure ratio engines will allow Mach 2 speeds and conserve fuel as well. www.globalsecurity.org indicated in an entry for the SST that the plane would cruise at Mach 2.7 without afterburner!
This would have given the SST military-rated "supercruise" ability in a civilian aircraft(!) U.S. military and intelligence agencies would be squirming about such a feat today, to be sure!
Lee said:That was the one I referred to. That's the way it was designed.
Absolutely right. The B2707 with turbofans would have had more of a problem unless the pressure ratio was increased.
I've seen more than one Gov't report that said the T/W for SST was also best at about .3-.4 for most economy. (1 lb thrust/3-4 lbs of takeoff weight.)
I saw in Jane's All the World's Aircraft for the Concorde and TU-144: Concorde climbed at about 9,800 ft/min and TU-144 did about 5,000 ft/min. A little faster than a 747, right?
Oh, yeah! Civilian pilots need to balance speed and climb angle carefully. Same with all planes, really.
I agree. I hadn't heard of the 85,000 lbs thrust engines, though.
And I agree. T/W wasn't high enough to do without A/B's.
I meant today after 9/11. The American military is on edge nowadays for that reason.
Sure, at that time you'd be right. But even the civilian who built a surplus F-104 may not have been seen as a 'patriot' by the today's military brass. A plane like that, even only at Mach one might be seen as a threat to national security. And, I rather believe Sir Richard Branson and his SpaceShipTwo are being watched closely by the authorities. Since I'm a veteran, I know how the military thinks. Viet Nam War era.