Originally Posted by
double_barrel
Could someone explain the significance of the displaced threshold in this discussion ?
In one way, the displacement is irrelevant because the crew thought the runway was unavailable.
But the report does discuss that runway 23 with its 1787' displacement was available for landing as if it was an obvious option for the crew. However, there is no discussion about whether it was realistic to expect a 747 to be landed on a runway like this. The weather was at minimums and it was nighttime. If this approach(LNAV or NDB) was to be flown, I would assume the crew would use VNAV with a 3° descent angle, which would put them in position for landing as if there was no displaced threshold. At 500' above the airport, the crew would have to disconnect the autopilot and then do some sort of level off or reduced descent rate maneuver to land further down the runway.
Perhaps no big deal, but I am just wondering if anybody in the larger aircraft types has done this sort of thing.........or if they were going into Halifax that night would they have chosen runway 14 even if they knew 23 was available.