SAIB 2026-16

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SUBJ: Elevator Control System SAIB: 2026-16 Date: September 10, 2026 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin advises owners, operators, and maintenance technicians of Textron Aviation Inc. (type certificate formerly held by Beechcraft Corporation, Hawker Beechcraft, Raytheon Aircraft, and Beech Aircraft Corporation) Model 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100, and B100 airplanes of the potential for corrosion in the elevator torque shafts. Some of these models are commercially referred to as King Air and Airliner models.

At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

The FAA received a report of extensive corrosion on the inside of an elevator torque shaft on a Textron Aviation Inc. King Air Model A100 airplane that was manufactured in 1977. During a scheduled inspection, the elevator torque shaft was found to show signs of surface corrosion. Further investigation revealed extensive corrosion on the inside of the elevator torque shaft as shown in Figure 1. It was determined that the rig pin hole on the elevator torque shaft assembly is susceptible to water ingestion and accumulation. This condition has the potential to cause corrosion on the inner diameter of the elevator torque shaft and on the taper pins, as shown in Figure 2. A contributing factor to the severity of the corrosion is the absence of an established inspection procedure for the interior of the elevator torque shaft.

Recommendations

The FAA recommends inspection and replacement of the elevator torque shaft assembly in accordance with Beechcraft Mandatory Service Letter MTL-27-03, dated June 6, 2023.

In addition, the FAA recommends reporting any findings of cracked, corroded, or damaged elevator torque shaft assemblies found during the inspection via email to ccb-cos@faa.gov. Please include the make, model, serial number, and total time in service of the aircraft. If possible, attach photographs of cracked, corroded, or damaged locations.

Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the OMB has approved the information collection contained in this SAIB and assigned OMB Control Number 2120-0731. All responses to this collection of information are voluntary; the nature and extent of confidentiality to be provided, if any. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to:

Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

For Further Information Contact

Soban Saeed, Aviation Safety Engineer, 1801 S Airport Road, Wichita, KS 67209; phone: (316) 946- 4123; email: ccb-cos@faa.gov.

For Related Service Information Contact

Textron Aviation, 2121 S Hoover Road, Wichita, KS 67209; phone: (316) 517-1700; email:

teamturboprop@txtav.com.

Figure 1 Corrosion on the inside of elevator torque shaft

Figure 2

Corroded taper pins