Twin Commander Technicians Train for SB Inspections

Nov. 29, 2012
The SB recommends that it be done only by technicians who have completed a special SB241 training class.

Creedmoor, NC, November 28, 2012 – Twin Commander Aircraft has launched a special training program for technicians who will perform the airframe structural inspections detailed in Service Bulletin 241, which was recently released.

The service bulletin calls for inspection and modification of the fuselage-to-wing-main-spar attachment in models 690, 690A and 690B Twin Commanders, with the exception of certain serial number 690As and Bs that have already been inspected and modified. (Later-model Twin Commanders – 690C/D and 695/A/B – have a different wing-to-fuselage design and are not affected by the service bulletin.)

Due to the complexity of the inspection process, the service bulletin recommends that it be done only by technicians who have completed a special SB241 training class developed and conducted by representatives of Twin Commander Aircraft.

“The service bulletin inspection requires a great deal of skill and attention to detail to be properly performed,” commented Twin Commander Aircraft President Matt Isley. “As we have seen in the past, significant damage can be done to the airframe, which can go undetected for a long period of time, due to improper modification. It is for this reason that we have recommended this work be done only by those shops that have received the proper factory training.

“We have worked with one of our most experienced service centers to bring the fleet a training program that will provide a comprehensive and practical learning experience in order to ensure that aircraft modified with SB241 will continue flying for decades to come.”

The two-day class begins with a presentation on the service bulletin, followed by a read-through of the document, examination of the provided drawings, and discussions of potential problems that could be encountered. Training aids provide visual and tactile reference.

The class concludes with a graded exam. Upon successful completion of the class, the technician is issued a reference CD with the presentation, the formal service bulletin, associated publications, and the relevant drawings in PDF format. The technician can refer to the CD while performing the service bulletin inspections. Each graduate receives an official certificate and verification stamp.

The class will be taught by Michael Grabbe, a highly experienced and knowledgeable instructor who has been working with Twin Commanders since 1974. Grabbe was a factory service representative at the Aero Commander Division of Gulfstream Aerospace, and later spent more than six years at FlightSafety International as Director of Maintenance Training in FSI’s Twin Commander program. He currently serves as Technical Advisor at Eagle Creek Aviation Services.

For more information about the SB241 technician training class, contact Michael Grabbe at 317-293-6935, or email [email protected]. For more information on Twin Commander Aircraft ( contact Matt Isley at [email protected].