[ QUOTE ]
how do you misuse a drag chute (I assume that's what they're talkin about with the emergency brake)
[/ QUOTE ] I know almost nothing about the Lears, but all the modern jets have back up systems for the brakes. Even though the Lear 25's are old, I would guess they would also have been required to have this. Since they referred to nitrogen pressure, the emergency brakes are probably nitrogen powered. If this is the case, there would be independent brake lines going to the wheel brakes into the same brake calipers used by the hydraulic system. If there is a total hydraulic failure, then N2 is sent to the brakes by a lever in the cockpit. These can be tricky to use, since they apply pressure to both wheels at once and you have to be careful how hard you press on the lever. At first it seems like nothing is happening, so you keep pressing harder. This can lead to a blown tire from a locked wheel if you are not careful.
To me the tower description of the jet landing fast and having the nose wheel in the air and the pilot describing 'aerodynamic braking' leads me to believe that the aircraft never 'made squat switch' when it landed. For the thrust reversers to deploy, you have to have both main wheels solidly on the ground. If you try to flare too much, then even when the wheels are on the ground, you may not activate the squat switches if a strut did not fully compress as it would in a normal landing. If the pilot gets caught up in why he can't pull the T/R levers up instead of using the brakes, you can eat up alot of runway. Especially if you prolong the flare. Again I have no knowledge of the Lear, but some of the more primitive electric antiskid systems may also not work correctly if the jet does not think it is on the ground. If the squat switches were not activated, then the brakes may not have acted the way they would on a normal landing.
To get the flight manual performance, you have to cross the threshold exactly at Ref, touch down about 1,000' down the runway with minimal flare and stand on the brakes for all you are worth. Anything less than an approach flown exactly by the numbers that results in an aircraft carrier like landing and max antiskid braking will result in a landing roll longer than book value. Coming in high and fast or 'floating' down the runway due to an excessive flare can eat up thousands of feet of runway. Getting distracted when you should be on the brakes can eat up more.
We don't know what really happened, there may have been a mechanical failure. But 7000' is a lot of runway. Even if the T/R's failed to deploy and the brakes failed, there should have been enough room to pop the drag chute and use the emergency brakes (assuming it had emergency brakes). The chute alone would probably not have stopped the jet, but would have made the impact less severe.
Always remember that brakes stop airplanes. Unless you are flying very large transports the accelerate stop performance and landing distance does not include T/R's.
