US investigators have disclosed that a Honda Aircraft HA-420 light executive jet was travelling above reference speed, and attempting to land in gusts above crosswind limits when it suffered a damaging excursion at Houston’s William Hobby airport.
The aircraft has a crosswind limit of 20kt, partly owing to its low wing position and short landing-gear which restrict bank angle during flare.
It had departed Miami Executive airport for Houston, with a pilot and five passengers, on 17 February last year.
According to the pilot’s testimony, he made two requests to the Houston approach controller to use runway 31L but was instructed to use runway 4.
US National Transportation Safety Board were unable to determine, from air-ground communications, whether or not a request for an alternative runway was made. But it says runway 4 was being used for landings and 31L for departures.
The HA-420’s initial ILS approach was aborted, by controller instruction, owing to an occupied runway.
As the aircraft conducted a second approach, the tower controller gave wind information to a departing flight which included gusts up to 25kt from 330° - presenting a crosswind component of 24kt.
When the HA-420 crossed the threshold it was travelling at 125kt, above the reference speeds of 100-111kt in the flight manual.
It touched down around 2,000ft from the threshold, initially tracking the runway centreline.
But its left-hand weight-on-wheels sensor transitioned from ‘ground’ to ‘air’ about 2s after touchdown. The aircraft had no wing-mounted speedbrakes.
The inquiry says a touchdown-protection function – to avoid inadvertent landing with a brake-locked wheel – prevents power braking until weight-on-wheels is confirmed for 3s.
“It is likely that the lack of positive weight-on-wheel parameters inhibited brake application,” it adds.
Investigators state that the excess airspeed, long touchdown, and transient weight-on-wheels detection are consistent with a float during the landing flare, and aileron input for the crosswind conditions.
The aircraft drifted left and veered off the runway at 75kt, losing the outer part of its right wing and sustaining a landing-gear collapse, before coming to rest in grass about 150ft north of the intersection of runways 4 and 31L.
None of the occupants of the jet (N14QB) was injured. The inquiry says the pilot had 287h on type.
