Strickerje From United States of America, joined Feb 2001, 723 posts, RR: 1 Reply 3, posted (11 years 5 months 1 week 9 hours ago) and read 7818 times:
I think he just means if it was allowed to fly the whole way at its typical supersonic cruising speed (which I'm pretty sure is Mach 2.0, 1330 miles per hour at 57,000 feet).
So let's consult Great Circle Mapper (http://gc.kls2.com/), shall we? (I love this website!)
The Great Circle Mapper says 1:52, which is a very rough estimate since it doesn't take into account the time to takeoff and climb or the prevailing wind (JFK-LAX is against the wind). So it's a bit more complicated than you probably hoped, but I hope this info helps anyway.
Jhooper From United States of America, joined Dec 2001, 6197 posts, RR: 13 Reply 5, posted (11 years 5 months 1 week 9 hours ago) and read 7786 times:
Using DUAT, I came up with 2:23. This takes the current winds into account, but it made the assumption that the aircraft would climb and descend to/from FL570 at 250 knots before accelerating/decellerating to/from 1330 knots, which probably wouldn't exactly be the case. Of course this doesn't take traffic flow / possible weather delays into consideration.
Last year 1,944 New Yorkers saw something and said something.
Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3 Reply 6, posted (11 years 5 months 1 week 2 hours ago) and read 7676 times:
Years ago Braniff number 1 had a route sharing with British Airways in which a Braniff crew would fly the Concorde from JFK to DFW and return. The maximum speed that they could fly, on this route, was Mach .95.
DeltAirlines From United States of America, joined May 1999, 8821 posts, RR: 12 Reply 8, posted (11 years 5 months 1 week 1 hour ago) and read 7580 times:
I would assume if Mach 2.2 was reached, then it would be able to do the route in 2-2.5 hours. The winds don't make a big difference with Concorde, since JFK-LHR is 3h55 and LHR-JFK is 3h55. Comparitively, BA's 777 on JFK-LHR is 7h05 and LHR-JFK is 7h40. It depends on how fast the plane goes (if you push it to max cruise speed or fly at economy cruise speed), as a BA Concorde has done JFK-LHR (or vice versa) in 2h31.
FlightSimFreak From United States of America, joined Oct 2000, 720 posts, RR: 0 Reply 9, posted (11 years 5 months 6 days 23 hours ago) and read 7516 times:
Quick question about the mach 1 over land rule... If you are flying at a speed that is faster than mach one at altitude, but slower than mach 1 at ground level, then the sonic boom will not be heard or felt. This is true... can the Concorde fly at some sub sonic at ground level but supersonic at altitude speed?
Shaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0 Reply 10, posted (11 years 5 months 6 days 21 hours ago) and read 7459 times:
No... because at its altitude it is supersonic so it will make a sonic boom. That will then travel to the ground and be very loud and scare people.
ANd flying at 600 kts at a lower altitude, where it is no super sonic, would do no good as it would be very inefficient fuel-wise. It can't travel as fast at lower altitudes due to the thickness of the air. Its gound speed would be slower and it would use more fuel trying to push it thorugh the thicker air. At 57,000 feet the air is much thinner so it requires LESS thrust to keep it at a HIGHER speed and uses LESS fuel and its ground speed is then much higher.
SO, to answer your question, no, it would not be economical nor as fast as up being supersonic at 57,000.
Sllevin From United States of America, joined Jan 2002, 3376 posts, RR: 6 Reply 11, posted (11 years 5 months 6 days 21 hours ago) and read 7452 times:
Yes, indeed, that's why it's measured on Mach numbers and not on Indicated Air Speed (IAS). Also, all the nasty aerodynamic behaviour is based on speed relative to Mach 1 (tuck, for example), so at higher altitudes it's the only important airspeed.
"Standard" airliners do the same thing. You can fly a 757 at a far higher speed at altitude than at sea level.
Someone else probably knows the specifics of IAS = M1.0. I think it's somewhere around 340 knots indicated (KIAS) at 41,000'. I do know offhand that 575 KIAS at 70,000' is Mach 3.0 in standard conditions.
Not a bad guess, but 250 kts up to FL 570 would be much too slow for Concorde at altitude - as I think you suspected.
The lowest authorised speed (VLA) is 250 kts up to FL410 and 300 kts thereafter, however even these speeds are far below the optimum climb speeds.
If we assume no speed restrictions whatsoever - a big assumption - Concorde’s optimum climb profile would be to achieve 400kts IAS by 5,000 ft, climb at that IAS to around FL320, accelerate to reach 530kts IAS by FL440, climb at that IAS until achieving Mach 2.0, at around FL510, which it would then maintain, in a cruise climb, up to FL600.
Again, I wouldn’t disagree with your estimate, but the maximum cruise Mach number for Concorde is Mach 2.0, and Concorde has never done 2h 31m across the Atlantic.
To date, the fastest Atlantic crossing achieved by Concorde, was on the 07 Feb 1996, Capt Les Scott, JFK-LHR, 2h 52m 59s.
Having talked to the crew about the unusually favourable conditions pertaining on that day, the winds and temperatures, the runways in use, and, perhaps most of all, the invaluable help from ATC on both sides of the pond, this is probably unbeatable.
Sllevin From United States of America, joined Jan 2002, 3376 posts, RR: 6 Reply 14, posted (11 years 5 months 6 days 17 hours ago) and read 7349 times:
Some interesting points of speed comparison.
The SR-71 once flew between NYC and London back in 1974 in 1 hour 54 minutes, an average speed of 1745 miles per hour, or about 2.6 Mach
In 1990, an SR-71 flew from BUR to IAD in 67 minutes. This was a full-blown, get special clearance maximum performance flight. I was still leaving just five miles from BUR almost directly under the departure path and I remember seeing the SR-71 streak off at maximum afterburner. They landed at IAD as hot as possible.
Given then averaged M3.2 for the entire trip, that's about as fast as it will ever be done. The only other aircraft which had that kind of range and performance was the XB-70, which was never 'production' enough for such attempts (a specific B-70 issue was that you couldn't retard below full military power in supersonic flight).