Japanese investigators have confirmed that the thrust reversers on a Japan Airlines Boeing 777-200 had already deployed before it suffered a tail-strike while landing at Tokyo Haneda and executed a go-around.
Flight-data recorder information shows the aircraft (JA701J) was on the ground for 25s, and that the tail-strike occurred 7s after main-gear touchdown.
The General Electric GE90-powered aircraft sustained an 11m (36ft), 50cm wide scratch on its underside aft fuselage, and distortion of the lower part of the rear pressure bulkhead.
The Japan Transport Safety Board states that the aircraft was landing on Runway 34L with wind from the north at 17kt following a flight from Shanghai on 31 March.
The aircraft touched down at about 145kt (269km/h), the throttles were retarded and the autobrake activated. Four seconds after runway contact both thrust reversers deployed.
However, after the aircraft landed it started pitching up to 10.9˚ - at the initial point of the tail-strike - then pitched to 11.8˚ and then 13.5˚ before becoming airborne again.
Engine thrust had fallen to about 30% of N1 when the tail-strike occurred and, about 3s after the impact, the thrust was increased, the thrust reversers stowed and the 777 took off again.
"For about 20s during the ground run the pitch angle was recorded at more than 10˚," the Transport Safety Board said in a preliminary bulletin on the event.
None of the 308 passengers and crew members was injured. The aircraft landed without incident on its second attempt.