Fighter Jocks and Old School Aviation Buffs give me a hand...
11-27-2007, 09:34 AM
#1
Gets Weekends Off
Thread Starter
Joined APC: Feb 2007
Position: CFII MEI
Posts: 331
Fighter Jocks and Old School Aviation Buffs give me a hand...
I have read in a couple of different places that the F-104 Starfighters best glide with T/O flaps up is 275kts... And they went on to say that above FL500, this is supersonic..
Ok is that true? I am having a bit of trouble buying it.
According to my calculation the speed of sound at FL500 would be
Speed of sound 761 mph X Speed of Sound Ratio at 50K on a standard day.. So 761 X 0.8671 = 659.86 mph
659.86 mph/1.15 = 573 knots...
K... thats not 275 knots... Am I missing something? Whats the deal? Anybody got any sources?
Ok is that true? I am having a bit of trouble buying it.
According to my calculation the speed of sound at FL500 would be
Speed of sound 761 mph X Speed of Sound Ratio at 50K on a standard day.. So 761 X 0.8671 = 659.86 mph
659.86 mph/1.15 = 573 knots...
K... thats not 275 knots... Am I missing something? Whats the deal? Anybody got any sources?
11-27-2007, 01:39 PM
#3
Line Holder
Joined APC: Aug 2007
Position: ATR-72 FO
Posts: 47
Speed of sound has nothing to do with altitude. Only temperature changes it. Of course, as you go up it gets colder. If I had an E6B around I would calculate what it would be, but I don't. FL500 would be tough, that's usually above the tropopause I think, so I don't know what ISA would be.
11-27-2007, 02:24 PM
#4
With The Resistance
Joined APC: Jan 2006
Position: Burning the Agitprop of the Apparat
Posts: 6,191
Yes, it is over Mach 1 at that altitude. Virtual E6B:http://www.luizmonteiro.com/Altimetry.htm
The human body in free fall can exceed Mach 1 from very high altitudes as was proven in balloon jumps from 100,000 feet. Joe Kittinger:http://www.youtube.com/watch?v=5BOK1aMIhp4
The human body in free fall can exceed Mach 1 from very high altitudes as was proven in balloon jumps from 100,000 feet. Joe Kittinger:http://www.youtube.com/watch?v=5BOK1aMIhp4
11-27-2007, 03:40 PM
#5
Gets Weekends Off
Joined APC: Feb 2006
Position: 767A (Ret)
Posts: 6,248
Lousiest glide ratio ever?
MGen Bob Rushworth used to tell about the time he had an uncommanded landing gear extension in the X-15 at Mach 3. The airplane had heated up and stretched, but the gear unlock cable did not stretch, so it was pulled. His glide was a lot shorter than planned, with a hideous rate of descent, but he made a successful landing on an alternate lakebed. 
11-27-2007, 06:00 PM
#6
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Joined APC: Aug 2006
Position: 737 Right
Posts: 1,385
Originally Posted by skycowboy
I have read in a couple of different places that the F-104 Starfighters best glide with T/O flaps up is 275kts... And they went on to say that above FL500, this is supersonic..
Ok is that true? I am having a bit of trouble buying it.
According to my calculation the speed of sound at FL500 would be
Speed of sound 761 mph X Speed of Sound Ratio at 50K on a standard day.. So 761 X 0.8671 = 659.86 mph
659.86 mph/1.15 = 573 knots...
K... thats not 275 knots... Am I missing something? Whats the deal? Anybody got any sources?
Ok is that true? I am having a bit of trouble buying it.
According to my calculation the speed of sound at FL500 would be
Speed of sound 761 mph X Speed of Sound Ratio at 50K on a standard day.. So 761 X 0.8671 = 659.86 mph
659.86 mph/1.15 = 573 knots...
K... thats not 275 knots... Am I missing something? Whats the deal? Anybody got any sources?
