About That 'Little Difference'

摘要

There are chilling similarities in the two incidents detailed in this month's Cause & Circumstance. Each involved highly experienced and competent crews. Each flight was at night, in weather and terminating on a contaminated or very wet runway. Each aircraft went off the departure end of the runway. Finally, each operated normally, except for one thing. While the late flare or the decision to land with a tailwind component probably less than 1 kt. above policy are certainly contributing factors and there may have been options at different points, the "One Little Difference" assured the unfortunate results. That little difference was not the same for each flight. One of the flights had systems operating in "manual" that they were used to using in "auto," the other had a system in "auto" that they were used to using in "manual." The reports have much discussion about going around when the approach is not stabilized. But go-arounds are possible only up to a certain point. When that has passed as a viable alternative, its attempted use could be disastrous. Further, both approaches were, in fact, stable - "textbook," in fact, until they weren't. The time lapse from a very good or perfect outcome to the overrun being nearly unavoidable was less than 3 sec. in both of these incidents. Not the perfect situation for learning ... or remembering.