This post is dedicated to Jim Zwayer, who died in this incident. He died, keeping the Cold War from ever turning hot.
The Blackbird was, ironically, the fastest jet plane; and at the same time, had to be flown like a hyper-miler in a Toyota trying to eke out every last mpg it could get. For various reasons, as an airplane's speed increases, it's center of lift changes. It moves farther back, towards the tail. Left uncorrected it will eventually push the nose down and the plane then enters a dive.
The answer to this in most airplanes is to trim the tail's flight control surfaces to point the nose upward to an equal and opposite degree that the change of center-of-lift wants to push the nose down. This is effective, but as you can imagine, drag starts to go through the roof and while the airplane can fly this way, the range in which it can fly is cut very short. This is fine for fighter jets. They're supersonic, but almost never fly at supersonic speeds; and when they do, not for long. Minutes, in most cases.
The Blackbird had to be able to cruise at Mach 3+ for hours on end, afterburners blasting the whole time. All kinds of tricks had to be employed to make those gigantic engines also be fuel-efficient enough, to fly for hours on somewhat less than a hundred-thousand pounds of JP-7.
One of the major tricks she employed was having seven different fuel tanks, with which she could manipulate her center of gravity while in flight. By manipulating the center of gravity, she could balance out the tendency to climb or dive without having to deflect the control surfaces. A major reduction in drag, which meant a major increase in efficiency, which meant she could fly higher, faster, and farther on that somewhat less than 100,000 pounds of JP-7.
The trade off though is: the farther aft an airplane's center of gravity is, the more difficult it becomes to control it's ability to fly straight and level at any altitude. In other words, the airplane suddenly wants to climb or dive, and the pilot has to watch it, carefully, every last second of the flight. The faster you go, the more demanding this becomes, and as the article reveals, it can suddenly exceed even the most amazing pilot's skills and the whole thing goes South faster than you even know what is happening at Mach 3+.
Air crew like Jim Zwayer knew _all_ of this going into the project. And yet they still climbed the ladder, got in the cockpit, and went for a flight. Because they knew how important all of this was.
So: to Jim Zwayer, Ray Torrick, and all the others who died in the accidents of the Blackbird project's combined programs. We owe all of you a debt we can never repay.
The story of a lucky SR-71 pilot who survived Blackbird disintegration at a speed of Mach 3.2 - Fighter Jets World
The Blackbird was, ironically, the fastest jet plane; and at the same time, had to be flown like a hyper-miler in a Toyota trying to eke out every last mpg it could get. For various reasons, as an airplane's speed increases, it's center of lift changes. It moves farther back, towards the tail. Left uncorrected it will eventually push the nose down and the plane then enters a dive.
The answer to this in most airplanes is to trim the tail's flight control surfaces to point the nose upward to an equal and opposite degree that the change of center-of-lift wants to push the nose down. This is effective, but as you can imagine, drag starts to go through the roof and while the airplane can fly this way, the range in which it can fly is cut very short. This is fine for fighter jets. They're supersonic, but almost never fly at supersonic speeds; and when they do, not for long. Minutes, in most cases.
The Blackbird had to be able to cruise at Mach 3+ for hours on end, afterburners blasting the whole time. All kinds of tricks had to be employed to make those gigantic engines also be fuel-efficient enough, to fly for hours on somewhat less than a hundred-thousand pounds of JP-7.
One of the major tricks she employed was having seven different fuel tanks, with which she could manipulate her center of gravity while in flight. By manipulating the center of gravity, she could balance out the tendency to climb or dive without having to deflect the control surfaces. A major reduction in drag, which meant a major increase in efficiency, which meant she could fly higher, faster, and farther on that somewhat less than 100,000 pounds of JP-7.
The trade off though is: the farther aft an airplane's center of gravity is, the more difficult it becomes to control it's ability to fly straight and level at any altitude. In other words, the airplane suddenly wants to climb or dive, and the pilot has to watch it, carefully, every last second of the flight. The faster you go, the more demanding this becomes, and as the article reveals, it can suddenly exceed even the most amazing pilot's skills and the whole thing goes South faster than you even know what is happening at Mach 3+.
Air crew like Jim Zwayer knew _all_ of this going into the project. And yet they still climbed the ladder, got in the cockpit, and went for a flight. Because they knew how important all of this was.
So: to Jim Zwayer, Ray Torrick, and all the others who died in the accidents of the Blackbird project's combined programs. We owe all of you a debt we can never repay.
The story of a lucky SR-71 pilot who survived Blackbird disintegration at a speed of Mach 3.2 - Fighter Jets World
