Dartzap wrote:Talk about a lucky escape
What, no credit to the crew for handling a loss of power? While luck was a factor, skill played a major role in so many people able to walk away from such a situation.
Wild speculation time: The gear collapse might have been related to the power failure - while there are back up systems to deploy landing gear with loss of power they don't always function perfectly and a gear collapse is always a risk during a power off landing. Also, lack of power can seriously cut down on the maneuverability of the aircraft, which means it may not be perfectly aligned with the runway and the resulting side-loads may also cause gear collapse. Although further review of the reports indicate this may have been more a problem of dragging the wheels through turf than a deployment problem.
You delay deploying the gear in a power-off landing because gear causes drag and with no power you want to very much conserve altitude and momentum as much as possible. Of course, you don't want to delay TOO long, or it won't come down and lock in time (another potential cause of gear collapse.
Likewise, depending on what is and isn't working and how well it's working you may arrive with a much different glide angle than normal, which could account for the very low approach. Given that the airplane didn't quite make the runway the pilot was probably trying to squeeze as much glide as possible out of the machine.
Also, given that the touch down apparently wasn't on pavement but onto sod I'm not surprised at all that parts of the landing gear were ripped off the airplane - 777's weigh an amazing amount, which would tend to drive the wheels into the ground. This brings the wheels to a very sudden stop while the rest of the airplane continues to move forward, with results as shown.
The "drop" at the end just before touchdown may have been the pilot attempting a full-stall landing - this slows down the airplane to the absolute minimum speed before contacting the ground. There is, obviously, some risk in doing this a little too high (you don't want to drop far enough to hurt yourself) but the idea is that by landing at the minimum possible speed you reduce the risk of injury from high-speed impact. Airliners such as that normally land around 120 mph/195 kph. They might be able to drop that down to 110 or even 100 mph with this technique (160-180 kph) which will reduce the momentum and kinetic energy involved in any upcoming impact. It will also shorten the stopping distance of an aircraft, which again reduces the chances of you crashing into something else. A full stall landing feels odd to the average person because they don't normally experience it, and it can feel like a drop or fall.
The thing is, they made it to an area where they weren't going to hit people or buildings, thus greatly enhancing the prospects of survival for all concerned.
