The Manx2 commuter aircraft that crashed at Cork airport, Ireland on 10 February killing the two pilots and four of the ten passengers may have stalled on short final approach, according to the interim factual report just released by the Irish Air Accident Investigation Unit.
The AAIU says that 7s before impact a warning horn sounded, "which is believed to be the stall warning", but the investigators want to ensure that it definitely was. The AAIU report refers to subsequent loss of control which led to a wingtip impact following which the Fairchild SA227 Metro III came to rest inverted: "Recorded data shows that the aircraft rolled significantly to the left as the aircraft tracked towards the runway centreline. This was immediately followed by a rapid roll to the right which brought the right wingtip into contact with the runway surface. Runway surface contact was made with a roll angle of 97 degrees to the right."
The report reveals that the Spanish-registered Metro (EC-ITP) had no autopilot or autothrottle and no flight director, so all flying was manual and the copilot was the pilot flying. Just before the warning horn sounded the aircraft had drifted off the approach and begun to parallel the instrument landing system localiser on its right-hand side.
The fatal approach was the third ILS approach attempted, and the second attempt at runway 17 which had a category II ILS and for which the decision height was 100ft (30m). The two previous approaches had been abandoned because of poor visibility in fog. The runway visual range passed on final approach was 500m, which was above the 300m minimum, and the crew's preferred alternate airfield, Waterford, was below minimums.
The report provides a reducing timeline to the impact point: with 9s to go there was a power reduction, followed by a power increase 2s later; at 7s the warning horn sounded and continued until impact; at 5s the terrain awareness warning system called "one hundred" [feet height on the radio altimeter]; at 4s the pilot not flying called "go-around" and the copilot acknowledged, but the descent continued, with the TAWS calling "fifty" at 4s and "forty" at 2s.
The AAIU says it has not, at this stage, found any evidence of engine or airframe malfunction, adding: "The investigation is examining, inter alia, the operational aspects of the flight including operational control and regulatory oversight. This will include the examination of the relationships between the air operator's certificate holder, the undertaking selling the service (Ticket Seller), and the undertaking which supplied the aircraft and flight crew."
The "ticket seller" was Manx2, the operator was Spain-based Flightline BCN, and the aircraft was owned by Airlada, based in Seville.