Interim preventative measures provide encouragement as manufacturer seeks long-term answer to recurring problem

A long-term action plan aimed at significantly improving Bombardier CRJ100/200 flap system performance is on the agenda for a forthcoming meeting between the manufacturer, regulators and operators.

Bombardier, US manufacturer Eaton, Transport Canada and six carriers last month discussed procedures being implemented to mitigate the spike in flap failures. The next meeting, scheduled for 7 May, will discuss long-term actions for the next winter season.

Canada's Transportation Safety Board in February issued a letter expressing concern for an increasing number of flap failures in the CRJ fleet and requested that Canada's minister of transport Lawrence Cannon issue advice on the agency's next steps for addressing the problem.

Already in the middle of a comprehensive review of the CRJ's flap system, the Canadian manufacturer at that time said it had determined the increase in flap failures is "very much related to winter weather" and that "cold-country operators are affected".

Since then, Bombardier "has been gathering relevant data from key operators to conduct root cause analysis on all areas affecting flap system reliability", says the airframer.

The company says a joint task team has been put together and has agreed a series of short-term actions that will be employed before October. This involves implementing a preventive screening programme and expanding maintenance procedures that address the specific demands of winter operations.

"Many of these actions have already been put in place during a particularly cold month by one operator and thus far the results have been extremely encouraging," says Bombardier.

Canada's TSB request came in the wake of a 21 November incident involving an Air Canada Jazz CRJ200ER that was cleared for a non-precision approach at Prince George, British Columbia. While established on final approach, and with the aircraft configured for the landing with flaps set at 45°, the flightcrew conducted a missed approach. However, the flaps did not retract when selected, remaining at 45°.

The flightcrew ultimately decided to divert to Fort St John, British Columbia. En route they attempted to recycle the flap circuit breakers, but this did not clear the fault. The aircraft landed without further incident.

The TSB also noted that a statistical review of its database of reported flap events since 2005 "indicates an ever-increasing number of flap failures experienced by CRJ aircraft".

Source: Flight International