12 March 2003
Cracked Spar Fitting
A Beech C90A operator has submitted a Service Difficulty Report (SDR) for a crack on the forward lower spar fitting (P/N 90-110035-1).
During the wing bolt replacement procedure, an AME noticed an oily streak on the lower spar fitting. After cleaning and further inspection, it initially appeared to be a deep scratch. Liquid Penetrant Inspection was performed, and the crack was revealed. The crack extends from the bottom of the fitting vertically 0.549'' and diagonally 0.760'' through the first section of the bottom-bonded lug. (See fig. B)
Crack on Spar is located at the forward bottom L/H Fitting
FAA Airworthiness Directive 89-25-10 and Transport Canada CF-1981-25R6 calls for attention to this area for a limited range of serial numbered aircraft. This crack occurred on an aircraft outside this range. However, the spar wing attachment inspection of this area is covered by the Beech Structural Inspection Repair Manual (SIRM).
The operator has advised Transport Canada that they have been instructed by Raytheon (Beech) to replace the entire spar as a result of this damage. The spar has been shipped to the manufacture for further analysis. The FAA has been advised of this issue and an investigation is in progress.
Transport Canada strongly recommends that operators and maintainers of Beech C90 series aircraft inspect this area for cracks at their earliest opportunity. Transport Canada also reminds AMEs to remain vigilant while inspecting this area during scheduled maintenance.
Any further defects or occurrences should be reported to Transport Canada, Continuing Airworthiness, Ottawa via the Service Difficulty Reporting program.
For further information, contact a Transport Canada Centre, or Mr. Jean Grenier, Continuing Airworthiness, Ottawa, telephone (613) 952-4343, facsimile (613) 996-9178 or e-mail email@example.com.
For Director, National Aircraft Certification
Acting Chief, Continuing Airworthiness