Deadline APPROACHING For SB237 Inspection
An important calendar deadline is looming regarding a required inspection of most 690 through 690B Twin Commanders.
Service Bulletin (SB) 237 requires that all affected aircraft, which includes all 690, 690A, and 690B Twin Commanders except for six serial-number specific aircraft, be inspected for evidence of corrosion between upper wing skin panels and engine mount beam support straps. The inspection must be performed within the next 150 hours time in service beginning January 8, 2010, or by January 8, 2011, whichever comes first.
SB237 was issued in May 2005, and in December 2009 the FAA issued Airworthiness Directive 2009-25-02 that mandates compliance with the service bulletin.
The inspection process involves removal of the upper engine nacelles to expose the engine mount beam support straps, and removal of the straps to inspect for corrosion on the exposed upper wing skins.
At a minimum, the steel engine mount beam support straps must be replaced with new straps that feature enhanced corrosion protection. If corrosion is found, the upper wing skins must be replaced. The service bulletin allows for various replacement options depending on the extent of corrosion. Different options can be used on right and left wings.
Twin Commander Aircraft LLC has prepared for the required inspection by having the necessary replacement parts kits available. By stocking up on kits, Twin Commander was able to avoid some steep price increases this year on material for SB237 inspection and rework kits.
Authorized service centers also have prepared by staffing up and sending technicians to special training at FlightSafety International. (Because of the complexity and critical nature of the work required to prepare the aircraft for the inspection, and the inspection itself, the service bulletin specifies that it be performed by technicians who have completed FSI’s SB237 course.) Service centers also have been alerting customers of the airworthiness directive, and have been offering guaranteed slots for owners who schedule ahead to beat the end-of-year rush for compliance.
Scheduling your SB237 inspection ahead of time ensures availability of resources at the service center and availability of parts from the factory. Owners are encouraged to take advantage of these factors and coordinate their inspection and other maintenance requirements with their service center to make sure hangar space is available.
If you own or operate a 690, 690A, or 690B that has not been through the SB237 process (and hasn’t yet logged 150 hours time in service since January 8, 2010), you have only a few short months—until January 8, 2011—to complete the inspection. Given the number of affected aircraft that have not yet been inspected, available slots at service centers that are authorized, equipped, and available to perform the inspection may be difficult to come by.
Contact your authorized Twin Commander service center today to schedule your SB237 inspection.
Discuss this article in the forums...
