In two Special Airworthiness Information Bulletins, the Federal Aviation Administration cautioned operators to heed the warnings of Bombardier (BBD) service bulletins dealing with faulty thrust reversers on CRJ 200s and flaps on the CRJ-100/200/440.
There have been several reports from operators regarding thrust reverser access cowls separating from the aircraft during taxi or flight operations. The latest was an Air Wisconsin incident out of Norfolk on February 25. The departed access cowl struck the left hand horizontal stabilizer and the vertical fin skull cap fairing, causing damage to both structures.
These events, including the Air Wisconsin, all have occurred immediately after an engine maintenance check, indicating the access cowls were not properly secured. Bombardier noted it was not a design or product problem, adding it has issued a number of service bulletins warning crews to visually inspect the studs and grommets of the power plant nacelle access panels for signs of damage or wear and replacing where necessary. A second SB advised operators to have mechanics and pilots ensure the upper and lower access cowls on the thrust reversers were secured prior to flight.
In February, the Transportation Safety Board of Canada issued a Safety Concern Letter. Bombardier has been working with the TSBC, its equipment manufacturers and operators to ensure continued safe operation of aircraft.
Operators have also reported flap malfunctions during cold weather operations caused by ice in the flap system components. Bombardier has an on going engineering investigation to address the root causes of this issue. The problem causes fuel shortage and landing distance issues as well as obstacle and climb performances issues.
Bombardier issues an All-Operators Message 1047 last month with guidance for operators in flap failure scenarios and FAA said an airworthiness directive was not warranted, as yet. The action results from a flaps failure last November which resulted in a fuel shortage on landing. The Air Canada Jazz crew, on a Vancouver-Prince George run, executed a missed approach owing to weather conditions. During the missed approach go-around, the flight crew selected their go-around flap position; however, the flaps remained in the 45-degree landing position. The crew then diverted to Fort St John, approximately 155 nautical miles away, which was not the alternate published on their flight plan. They had to declare a fuel emergency owing to fuel consumption calculations. The aircraft ultimately landed at an airport slightly closer than the alternate with approximately 500 lbs of fuel remaining. The incident is still under investigation in Canada.
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 company is trying to increase overall system reliability and, specifically, reducing cold temperature related system faults and expects to release short-term actions in September or October. It initiated a complete flap system review involving a multi-disciplinary team including Bombardier, the system supplier Eaton Aerospace, and a representative group of operators. The team is reviewing all aspects of the system, examining all known modes of system malfunction, especially related to cold, and developing a short-term mitigation plan as well as a medium-to-longer term system improvement package to actively address cold weather system reliability.