Technically: Service Bulletin 53-4173: Fuselage – Brake Master Cylinder Support Tube Inspection

Issued: June 28, 2017

Effectivity: Beechcraft Super King Air C90GTi, Serial Numbers LJ-2091 thru LJ-2095, LJ-2097; Beechcraft Super King Air B200, Serial Number BB-2019; Beechcraft Super King Air B200GT, Serial Numbers BY-194 thru BY-201; Beechcraft Super King Air B300, Serial Numbers FL-889 thru FL-902, FL-904 thru FL-907.

Compliance – Recommended: This service document should be accomplished at the next 400-hour or 12-month (annual-type) inspection.

A service document published by Textron Aviation may be recorded as completed in an aircraft log only when the following requirements are satisfied:

1. The mechanic must complete all of the instructions in the service document, including the intent therein.
2. The mechanic must correctly use and install all applicable parts supplied with the service document kit. Only with written authorization from Textron Aviation can substitute parts or rebuilt parts be used to replace new parts.
3. The mechanic or airplane owner must use the technical data in the service document only as approved and published.
4. The mechanic or airplane owner must apply the information in the service document only to aircraft serial numbers identified in the Effectivity section of the document.
5. The mechanic or airplane owner must use maintenance practices that are identified as acceptable standard practices in the aviation industry and governmental regulations.

No individual or corporate organization other than Textron Aviation is authorized to make or apply any changes to a Textron Aviation-issued service document or flight manual supplement without prior written consent from Textron Aviation.

Textron Aviation is not responsible for the quality of maintenance performed to comply with this document, unless the maintenance is accomplished at a Textron Aviation-owned Service Center.

Reason: The brake master cylinder support tube may have incomplete welds.

Description: This service document provides instructions to do an inspection of the pilot’s and copilot’s master cylinder support tubes.