Aviation Partners has issued a Service Bulletin for the Hawker Beechcraft/BAE 125 Series 800A/B, C-29A, Hawker 800 and Hawker 800XP. The Service Bulletin provides instructions to reduce the maximum permissible altitude to FL340 from FL410. The altitude limitation is implemented by an Airplane Flight Manual limitation and placards installed on the instrument panel.
Aviation Partners and the FAA consider this Service Bulletin to be a safety-related limitation until a design change to preclude the oscillations is developed and FAA approved.
Aviation Partners COO Hank Thompson said several instances of aileron/wing oscillations have been reported on the Hawker 800 series. According to Thompson, his company has designed a solution that requires the re-mass balancing of the aileron. That fix is on track to be flight-tested by early next month, and Thompson expects the solution will be approved by the FAA and available to customers by the end of June.
The resulting alternate means of compliance will remove the altitude restriction.