Originally posted by C0bzz
What if an Airforce pilot has a degree in Aerospace Engineering?



Like I said, you fly boys crack me up.

I *think* test pilots are required to...

Originally posted by Zaphod58
NASA wanted to modify them to do it EVERY FLIGHT and to be able to SUSTAIN that speed.

You might be right there, i.e. if your willing to risk damage you can push to over Mach 3.4something.


I'll dig some more and post back.

Ok, here we go:

Lockheed secret projects - Inside the skunk works
Zenith Press

Dennis R. Jenkins

The maximum performance of the Blackbird is only now becoming well understood. The SR-71 was intended for flight at altitudes approaching 85,000 feet, with sustained cruise speeds approaching Mach 3.2. The smaller and lighter A-12 could better each of these by a small margin. During its operational career, the SR-71 rarely exceeded these design speed or altitude limits. Studies have been conducted by Lockheed and NASA that show speeds in excess of Mach 3.5 could be achieved for 10 to 15 minutes. The studies indicated that increasing the maximum speed to Mach 3.4 would not require any additional modifications to the aircraft, but for sustained flight between Mach 3.4 and Mach 3.5, the inlet hydraulic lines and actuators would need to be better insulated to protect them from the additional heat. NASA had planned to conduct an envelope expansion program for the SR-71, but ever tightening budgets led to these plans being canceled in the early 1990s. The only structural limitation related to speed above Mach 3.5 is an absolute limit of 420 knots equivalent airspeed (KEAS), set by inlet duct temperatures and pressures which exceed acceptable values. Other factors that limit speed above Mach 3.5 are inlet capture area and excessive engine compressor inlet temperatures (CIT).

One of the NASA studies also addressed achieving higher altitude flight. The results indicated that a "zoom climb" profile would allow reaching 95,000 feet for a short time with an aircraft gross weight of approximately 85,000 pounds. The aircraft would be accelerated from Mach 3.2 to Mach 3.5 at an altitude of 80,000 feet, then zoomed to 95,000 feet, with speed decaying back to approximately Mach 3.2. The aircraft would subsequently settle back to an altitude of 84,000 feet. Factors which limit sustained flight at altitudes above 85,000 feet are wing area and total thrust. It would be possible to replace the outer wing panels with larger ones to provide additional wing surface area and allow sustained flight above 85,000 feet.

Yeah but you know some people will still insist the flight manual is just government disinfo and that it can really do Mach 15 and fly in low earth orbit

Well, there is more to determining top speed than one simple equation.

One should study aerodynamics further.

As far as ultimate top speed of the SR-71 and its versions;

Mach 14 is a bit out of touch for the sr-71.

However 3.5 is far from its actuall top speed.

Mach 7.2 to an upper limit of mach 10 would be a better guess.

Ok my turn to weigh in on this sillyness. Lol. I'm pretty sure the only man made objects achieving mach 14 are space vehicles and now some solid projectiles being fired from railguns. My dad was in the air force and flew f-111's and he had a friend, Blair Bozek, who flew sr-71s and had to eject from one incidentally, google all of this for proof, and he claims the aircraft could fly much faster and higher than the published numbers. I took that to mean probably close to or slightly above Mach 4 and higher than 100,000 ft. As far as I can tell, it seems the only high speed limitations would be temperature limitations. It seems to me that the aircraft had enough thrust to propel it to thermal destruction at altitude. As far as the max altitude goes, meh, I don't care too much for that. I think the speed is more interesting. I listened to Richard Graham speak about flying the sr-71 at eaa oshkosh airventure and he said the highest external temperature reached during his flights was around 622 fahrenheit right at the base front of the cockpit glass, and that is where he heated up his tube food by placing it on the dash for 1.5 minutes a side lol. I think mach 4 was feasible, but I imagine there were temperature constraints. It's extraordinarily hard to push things through the air that fast. That is why the top speed for a production car is only 258 with the shelby supercar and that thing is using 1150 horsepower, absolutely ridiculous! As far as the antigravity technology for the B-2, whoever believes in that is drinking drano. lol. Why would they put wings on it if they had anti-gravity duhhhhhh. If you are still a skeptical moron, watch the b-2 crash on youtube, or just start taking engineering classes and learn more. Absolutely ridiculous. I mean cmon people, apply some logic! Read some more! Jeez. Oh by the way, an australian training with my dad's squadron got the F-111 up to 1263 knots indicated air speed 200 ft above the deck in death valley california in the 1970's. Fastest low level airspeed of any aircraft ever. Unless somebody comes up with a number for the Mig-25, which seems like the only other aircraft I could think of approaching that speed. 1263, thats what the analog said. The guy's name was Andy Pellequin. He was notorious for doing alot of other things that were looked down upon as well.