Service Bulletin MTB-57-01: Wings – Inspect the Aft Upper and Lower Wing Bolts for Correct Washer and Replace if Needed

Date: March 5, 2020

Effectivity: King Air 90 (applicable variants within defined LJ serial number range), LJ-2055 through LJ-2129; Super King Air 200/B200, serial numbers BB-2019 through BB-2021; Super King Air 200C/B200C, serial number BL-171; Super King Air B200GT, serial numbers BY-152 through BY-261; Super King Air B200CGT, serial number BZ-1; Super King Air B300, serial numbers FL-817 through FL-1065 and Super King Air B300C, serial numbers FM-53 through FM-66.

Reason: To inspect the aft upper and lower wing bolts for incorrectly installed 95-110025-3 Washer, and if installed replace with a new 95-110025-7 Washer.

Compliance – Recommended: This service document should be accomplished at a scheduled maintenance period or inspection, not to exceed 200 flight hours.

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.

Service Bulletin 34-4171 R1: Navigation – ProLine Fusion Upgrade to Phase 3 Software

Original Issue: November 15, 2019

Revision 1 Issue: March 12, 2020

Revision Compliance – No Effect: Airplanes previously modified by this service bulletin are not affected by this revision.

Description: Note: This revision replaces the original issue of SB 34-4171 in its entirety.

  1. Updates Step 1 for Aircraft Personality Module (APM) strapping.
  2. Updates Steps 15B(1) and 15C(1) to go thru Step 15H.
  3. Updates Step 22 to provide more instruction for the Pilot’s Operating Handbook and FAA Approved Flight Manual.
  4. Updates the Flight Crew Operations Summary.

The information provided in this column may be abbreviated for space purposes. For the entire communication, go to

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