Problema sul volo BA056 JNB - LHR

[Killua_727]

Spero non sia già stato postato:

"Incident: British Airways B744 at Johannesburg on May 11th 2009, two thrust reversers indicated open, leading edge flaps retracted
May 12th 2009

The crew of a British Airways Boeing 747-400, registration G-BYGA performing flight BA-56 from Johannesburg (South Africa) to London Heathrow,EN (UK), decided to dump fuel and return to Johannesburg after two thrust reversers were indicated unlocked after takeoff. The airplane landed safely about 120 minutes after takeoff.

Engineers determined that the indication was false, the thrust reversers had been properly locked in closed position.

The flight was initially postponed by 23 hours and later cancelled.

New information leaked by aviation sources in South Africa on May 13th - claimed to be based on the readout of the digital flight data recorder, cockpit voice recorder as well as testimony of the flight crew - suggests, that one engine flamed out during rotation for liftoff, another engine uncommandedly rolled back to idle at the same time, two engine thrust reversers indicated unlocked and the leading edge flaps retracted. According to that information the crew levelled off at 35 feet AGL, managed to recover the idle engine and resumed the initial climb out on three engines. Subsequently the crew dumped fuel and returned to Johannesburg for a safe landing. South Africa's Civil Aviation Authority (SA CAA) is reported to have impounded the airplane.

Other aviation sources in South Africa on May 14th also claiming to have seen the developing report by SA CAA deny, that there was any loss of thrust, no engine flamed out, no engine rolled back to idle. Those sources however confirm, that engines #2 and #3 showed spurious thrust reverser unlocked indications while the airplane was still on the ground causing the leading edge flaps to be automatically retracted by system logic. The stick shaker came on at a height of 12 feet, the crew levelled off at about 40 feet, accelerated and continued the climb. At about 160 feet AGL the leading edge flaps came back down to their commanded deployed position.

British Airways declined to comment pointing to the ongoing investigation by South Africa's Civil Aviation Authority and stated, that they are fully cooperating with authorities of South Africa.

The investigator in charge at South Africa's Civil Aviation Authority told The Aviation Herald on May 14th, that the flight recorders have not yet been analysed. The investigator confirmed, that the thrust reversers for engines #2 (inner left) and #3 (inner right) indicated unlocked during the takeoff roll beyond V1 leading to the automatic retraction of leading edge flaps in accordance with the system design. The stick shaker activated at 12 feet, the crew levelled off at 35 feet, picked up speed and then resumed the initial climb. However, the SA CAA does not yet rule out, that there have been additional problems with the engines pending analysis of the flight recorders.
"

Da AviationHemerald