The FAA issued a special airworthiness bulletin on October 7 alerting operators of the Raytheon Beech Premier I that the agency has determined that the jet’s flap actuators are “nonconforming” parts, fabricated from material that might be subject to “brittle failures at cold temperatures.”
There have been no reported failures of flap actuators on the more than 65 Premier Is in service, but the components are made by MPC Products of Skokie, Ill., and are similar to the actuator that MPC made for the horizontal stabilizer of the Learjet 45.
In the Learjet case, the FAA decided that while the part was an improvement over an older one (failure of which led to a crew nearly losing control of their aircraft), the new part was “not manufactured per the type design data” and a “brittle fracture” could occur. That assessment led to the recent temporary grounding of the Learjet 45 fleet. The FAA has since allowed Learjet 45s to return to operation once they have been fitted with a reworked actuator.
Raytheon, MPC and the FAA were working to resolve the issue, but at press time it was unknown when or if subsequent action would be required. Meanwhile, Raytheon Aircraft has issued a temporary change to the Premier I flight manual advising pilots to operate the flaps only in 10-degree increments at a time and not to operate them at all with the autopilot on.
Wing-flap actuators are not as critical as horizontal stabilizer actuators, a Raytheon spokesman pointed out.