Operators of Bombardier Challenger 604 business jets have been warned of a fuel migration issue uncovered during flight testing in support of the investigation into last October's fatal take-off crash in Wichita, Kansas.
During acceleration and/or climb, fuel can migrate between the 604's unbaffled fuselage and the centre wing tanks causing the aircraft to exceed its aft centre of gravity (C of G) limit.
Canadian and US authorities have issued an emergency airworthiness directive (AD) instructing operators to move the aft C of G limit forward at weights above maximum landing.
It is not known whether a C of G shift due to fuel migration was the cause of the October accident, in which a Challenger 604 crashed on take-off from Bombardier's Wichita flight test centre. Two crewmembers were killed and the third died later of severe burns.
The fuel migration was discovered during a test flight in support of the US National Transportation Safety Board's accident investigation.
There are 180 Challenger 604s in service. Earlier versions of the aircraft are not affected by the AD as they do not have the fuselage tanks introduced on the 604 to extend range. Bombardier is working on a fix, and assures that complying with the AD will not reduce the aircraft's 7,400km (4,000nm) range.
Source: Flight International
