US investigators have determined that a Learjet 35A sustained serious damage during an overrun, after the crew failed to conduct a go-around despite an unstable approach in a tailwind.
The aircraft had been flying from Albuquerque to San Marcos regional airport near Austin on 2 January last year.
While in cruise the crew received automated weather information which indicated wind from the northeast.
The crew had briefed for an ILS approach to runway 13, and this was cleared by the tower.
But the National Transportation Safety Board says the wind had turned to the northwest – gusting up to 24kt from 310° – which resulted in a strong tailwind component.
“[The crew] did not request current weather during the descent, and no weather information was provided by the tower controller,” says the inquiry. The runway was wet.
Recorded data showed the aircraft had a 15kt tailwind during the approach and a descent rate exceeding 2,000ft/min about 10s before the landing, reducing to 1,000ft/min about 3s before.
The manufacturer’s flight manual lists the maximum tailwind component as 10kt.
Analysis of the approach found the jet touched down at 124kt about halfway along the 5,600ft runway, leaving some 2,600ft remaining in which to stop.
Performance calculations indicated the aircraft’s landing distance on a wet runway was 4,550ft.
According to the first officer’s testimony, he had pointed out the runway to the captain in the poor visibility, after the jet broke out of cloud at 500ft.
He also told the inquiry that the captain “abruptly chopped power and descended to land at a rapid pace”.
The captain stated that that, after touchdown, he applied the brakes and deployed spoilers but the jet did not appear to decelerate.
Realising that the aircraft would overrun, he veered the jet to the left to avoid the localiser antenna at the runway end. The jet travelled into a grass field and its nose-gear separated.
Although the five occupants were uninjured, the aircraft received substantial damage to its nose and forward fuselage.
Investigators have concluded that the crew had been unaware of the prevailing winds and pursued an unstable approach, with neither pilot calling for a go-around.
