Emirates 777 Rough Landing in Dubai

BobDDuck said:
BtV is a system that configures auto braking to have the aircraft slowed by a certain taxiway for an exit. It is predicated on touching down at a certain point (normally via autoland, but not always) and slowing the plane at a rate to be a safe taxi speed at the selected taxiway. If BtV is activated and you don't land by a certain point, it will trigger the long landing alert, even if there is plenty of runway to stop on because it won't be able to make the selected taxiway.

That may not have been in play at all here though, so who knows.



Small plane (lack of) problems. The gear in a CRJ in a landing pitch attitude hangs about 9 feet lower than the flight deck. In a bigger plane, that number can be upwards of 30 to 50 feet.
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Yeah, but if we're talking where the gear touches down (not the cockpit) you'd still have the same clearance at the threshold, no? You'd certainly have to have your eyes higher on the papi in the longer airplane to put the wheels in the same place but if you're putting the mains on the 1000' markers 3* still puts them at 50' over the threshold. The only difference I see is whatever difference there is (probably really significant actually) between types in the distance the aircraft travels between the aim point and the touchdown point, but I'm not even sure if that's relevant terminology to a part 25 jet and how you handle landings.
 
Roger Roger said:
Yeah, but if we're talking where the gear touches down (not the cockpit) you'd still have the same clearance at the threshold, no? The only difference I see is whatever difference there is between types in the distance the aircraft travels between the aim point and the touchdown point, but I'm not even sure if that's relevant terminology to a part 25 jet and how you handle landings.
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Yes, we are talking about where the gear touches down, but with a bigger plane, using "normal" descent rates all the way to the runway, it may not be possible to get it on the 1000 foot marker and not, potentially take out some lights.

It's more about the attitude of the plane during landing multiplied by the length the gear is behind the cockpit.

This picture is from Code7700. I've always been impressed with Eddie's analysis. The cause of the accident highlighted was different, but it does discuss some of the Eye to Wheel height calculations.

http://code7700.com/mishap_bd-700_c-gxpr.html

deck_angle_bd700_v_cl604.png
 
BobDDuck said:
Yes, we are talking about where the gear touches down, but with a bigger plane, using "normal" descent rates all the way to the runway, it may not be possible to get it on the 1000 foot marker and not, potentially take out some lights.

It's more about the attitude of the plane during landing multiplied by the length the gear is behind the cockpit.

This picture is from Code7700. I've always been impressed with Eddie's analysis. The cause of the accident highlighted was different, but it does discuss some of the Eye to Wheel height calculations.

http://code7700.com/mishap_bd-700_c-gxpr.html

deck_angle_bd700_v_cl604.png
Click to expand...
I think that's what I was getting at with the comment about aim point vs touchdown point, but I'm not sure. Have to read your linky in detail.
 
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