Canadian safety board officials investigating the 2 September Swissair Boeing MD-11 accident off Halifax, Nova Scotia, are concerned that they may be unable to find crucial physical clues before winter sets in. Wreckage located so far is small, and the flight data recorder (FDR) and cockpit voice recorder (CVR) stopped simultaneously about 6min before final impact. The investigation, warns the Transportation Safety Board of Canada (TSBC), is likely to be "a lengthy, painstaking process".

The Swissair MD-11 crew had declared a full emergency three times in 20s, just 45s before a power failure simultaneously stopped radio communication and both flight recorders. During the remaining 6min of flight, the aircraft carried out an irregularly flown, slow right turn through 360¼, before crashing into the sea.

The TSBC says that CVR information is still being correlated with other data, including air traffic control voice recordings, radar plots and FDR information. The FDR data, it says, contains "several anomalies" which appear to have been fed from the No 1 air data computer - which has been recovered - just after the emergency call.

Source: Flight International