Friday, April 06, 2007

Special Airworthiness Information Bulletin for CRJ aircraft

FAAThe U.S. Federal Aviation Administration (FAA) has issued a 'Special Airworthiness Information Bulletin' (SAIB) for Bombardier Model CL 600-2B19 aircraft (CRJ 100/200/440).

The SAIB says that operators have reported numerous incidents of flap failures during cold weather operations, and that "water ingress into flap system components with subsequent freezing appears to be a significant factor."

As previously reported in AOM 1020, a recent flaps failure occurrence resulted in a fuel shortage on landing. The crew executed a missed approach due to weather conditions at the destination airport. During the missed approach, the flaps could not be retracted from the 45-degree position.

The crew began a diversion to their alternate airport, and declared a fuel emergency due to fuel consumption calculations. An airport slightly closer than the alternate was selected, and the aircraft landed safely with approximately 500 lbs of fuel remaining.

There have also been a number of reported cases of flap system malfunctions where
the flaps either do not extend at all or fail to extend significantly out of the 0 degree position. Fleet data shows that the rate of occurrence of these events increases during operation in cold temperatures. The increased frequency of these events is the subject of a detailed Bombardier and system supplier investigation. In the interim, flight crews should be aware of the possibility of these kinds of events.

Operations to remote or runway limited airfields, or operations involving wet or
contaminated runways may have to be reviewed and guidance provided to the crews to ensure that the risks of flap failures have been mitigated.

Operators should verify that their flight crew members are provided with the appropriate information, such as that found in the Performance section of QRH Vol. 1 and associated training, with emphasis on decision-making and performance considerations for these situations. Issues such as night operations and/or early closure of some airports, due to reduced business volume, may reduce the availability of some potential diversion airports. [SAIB: NM-07-26]
In addition to fuel shortage and landing distance issues, there could potentially be obstacle clearance and climb performance issues.

Click here for a printable ('pdf') version of SAIB: NM-07-26.