Posted on 05/09/2023 5:48:49 AM PDT by DUMBGRUNT
No story on the SR-71 would be complete without an understanding and appreciation of just how valuable the KC-135Q model tankers and their crews were to the successful and safe completion of every mission.
“We had to refuel right after takeoff for only one reason, and it wasn’t because we leaked JP-7 fuel on the ground. Yes, the plane does leak fuel, but not enough to require refueling after takeoff.
“The JP-7 fuel reaches temperatures well over 300 degrees F. during Mach 3 cruise, making the fumes in each of the six fuel tanks very volatile and potentially explosive. The metal skin of the aircraft approaches 400 degrees F., adding to the volatility of the fuel inside the tanks. One of our aircraft limitations was a maximum speed of Mach 2.6 without an inert atmosphere inside the fuel tanks."
(Excerpt) Read more at theaviationgeekclub.com ...
Love the sound of the Friden.
https://www.thesr71blackbird.com/Aircraft/Engines/j58-the-powerplant-for-the-blackbirds
FTA: The Pratt & Whitney J58 (company designation JT11D-20) was a jet engine that powered the Lockheed A-12, and subsequently the YF-12 and the SR-71 aircraft. The J58 was a single-spool turbojet with an afterburner. It had a unique bleed from the compressor to the afterburner which gave increased thrust at high speeds. This feature caused it to be referred to as a turboramjet in some writings.
An amazing engine in an amazing aircraft.
The aircraft also had stealth characteristics.
—”How does one defuel 15000 pounds of fuel?”
While still on the ground the fuel is returned to the tanker truck.
The fuel was used to safely purge 100% of the air from the tank, as the fuel is withdrawn a low-pressure nitrogen charge is placed on top.
That makes sense...
One of my college professors had one of those in his office.
Many keys, but could it do extraction of roots, trig functions, logs...?
“Love the sound of the Friden.”
Dividing by zero was always fun to listen to.
Yep, it was designed to do everything, but does nothing very good. The F-16 OTOH was designed by to be an air superiority fighter ONLY and does it very well.
Hey, I thought I had it!
“
The RamJet was very inefficient at low speed, because it relies on compression of air to burn the fuel effectively. “
I’m into pulsejets and ramjets as a hobby, maybe even an invention. I have a chart somewhere that shows ramjet efficiency equals turbojet at about Mach 2.4.
—”Interesting link as to moving her from the Burbank to Area 51.”
NICE!
With fuel tank truck I guess. When I was in the Air Force we had a "button pusher" guy playing with controls in the cockpit that he knew nothing about and set the switches to dump fuel. When someone later applied power to the airplane, it proceeded to dump 12,000 lbs. of JP-4 onto the tarmac.
“”””In Israel we were all still trained with slide rules, and still are, assuming that, during our lifetime there will be a major EMP attack, destroying computers.””””
In 1972 in Artillery FDC we spent a few days training on the FADAC computer, which we thought was wonderful and so much more fun than the slide rule, but after those days the Army told us they hoped we enjoyed it but that we would probably never see it again because the slide rule was the only thing we could depend on in a major war.
—”There were no computers. Desk tops, lap tops were far into the future.”
And when TI finally came out with a scientific pocket calculator, I was too cheap to purchase one, plus I was never wild about RPN.
As a trainee, I worked for slide rule wizards!
True math masters at that time.
—”Coolest. Plane. Ever.”
TRUE!
I have a large SR-71A poster on my wall.
“That’s nothing. The F-35 was designed with a committee.”
lol! Nice!
“could it do extraction of roots, trig functions, logs”
One could use it to interpolate between table entries....
A weight-on-wheels switch should prevent that. Maybe it was disabled for maintenance or testing. There’s always one guy who will mess around with things and has no idea what he’s doing.
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