An initial bulletin on the fatal 4 January Bombardier Challenger 604 take-off crash at Birmingham International Airport, UK, says that nothing appeared wrong with the airframe, engines, systems or the crew, but the aircraft went out of control as soon as it lifted off the runway (Flight International, 15-21 January).

The UK Air Accidents Investigation Branch (AAIB) says the 604 rolled dramatically to 50° left bank within 2s of unstick, then the wingtip hit the ground. The aircraft's last recorded attitude was 111° left bank and 13° nose-down pitch. Both pilots and the two passengers on board were killed.

The AAIB bulletin reports good weather and light winds with a temperature of -2°C (-33°F) at take-off. Flap 20 had been set, the take-off speeds were correctly calculated and executed, according to the investigator, and no audio warnings except one for bank angle were recorded.

No maintenance actions were reported to have been carried out between the aircraft's arrival from the USA the previous day and its departure. Icing appears to be an area that the AAIB will investigate further. The aircraft, operated by US-based Epps Aviation, was parked outside, and there was no precipitation, but overnight temperatures had dropped as low as -9°C. The Challenger was fuelled to full tanks shortly before its take-off for Bangor, Maine. The bulletin notes: "Other aircraft parked overnight were de-iced during the morning with associated reports of moderate to severe ice or frost accumulations." The Challenger's crew, however, did not request de-icing, neither was a checklist call for wing or cowl anti-icing recorded.

The AAIB has called for a full inspector's investigation.

Source: Flight International