Alex Zudin/Moscow
A Bombardier Challenger 604 crashed on take-off near the Kazakhstan city of Almaty after the captain failed to turn on the anti-icing protection systems despite the low temperature and presence of snow, an investigation by CIS interstate aviation committee MAK has found.
One member of the crew died in the crash. The other pilot, one cabin crew member and the only passenger were all seriously injured.
The accident, which destroyed the aircraft, operated by JetConnection Businessflight, took place at night on 25 December 2007.
Weather conditions at the airfield were light snow, a temperature of minus -14C (6.8°F), 93% humidity, and 8/8 cloud at 395ft (120m) altitude. The aircraft was treated with Type 2 de-icing fluid by ground services 25min before take-off, which MAK found was carried out adequately, and was checked by the crew visually.
The investigation revealed that the crew used JetConnection Businessflight's abbreviated checklist before take-off, which omitted several actions in the flight manual, including checks on the onboard anti-icing system.
An investigator from Germany's BFU accident investigation unit concluded from listening to the cockpit voice recorder that the captain wrongly decided that the previous external de-icing alone was sufficient.
The captain decided he would use maximum engine thrust for take-off, rather than using the anti-icing system that bleeds hot air from the engines to heat the leading edges of the wings and stabiliser and thus degrades thrust.
Bombardier, which took part in the investigation, found the aircraft's wing anti-ice systems switch was in the off position at the time of the crash.
As the aircraft took off, it rolled right after leaving the ground, went off the edge of runway, then hit the airfield boundary fence and crashed and caught fire.
MAK found the aircraft crashed because of asymmetric lift on the wings caused by ice formation.
It has recommended the operator to revise its abbreviated checklist to conform to the manufacturer's flight manual and that pilots of this type of aircraft should be made more aware of the hazard from icing in the cold weather seasons.
Source: Flight International
