SAIB 2026-09

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SUBJ: HYDRAULIC POWER, Hydraulic Power Transfer Unit System SAIB: 2026-09 Date: April 6, 2026 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin advises owners and operators of The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes of errors identified within Boeing Alert Requirements Bulletin 757-29A0071 RB, Original Issue, dated November 16, 2023, which is mandated by airworthiness directive (AD) 2024-25-09. This SAIB also provides recommended actions to address this concern.

The FAA has determined that this airworthiness concern is an unsafe condition that warrants AD action under Title 14 of the Code of Federal Regulations (14 CFR) part 39. The FAA anticipates superseding AD 2024-25-09 after the design approval holder has revised the required service information to correct the errors. The documents referenced in this SAIB are recommendations from the design approval holder and are not FAA mandatory requirements.

Background

The FAA issued AD 2024-25-09, Amendment 39-22911 (90 FR 1850, January 10, 2025) (AD 2024- 25-09), for certain The Boeing Company Model 757 airplanes to address failure of the power transfer unit (PTU) control valve, which, in conjunction with a loss of the left engine or engine-driven pump during takeoff, could result in failure of the landing gear to retract in a timely manner. This condition, if not addressed, could add additional drag, affect climb gradient, and prevent the ability to clear obstacles on takeoff, resulting in loss of continued safe flight and landing. AD 2024-25-09 requires accomplishing Boeing Alert Requirements Bulletin 757-29A0071 RB, Original Issue, dated November 16, 2023.

Since the FAA issued AD 2024-25-09, an operator reported errors in the instructions that could prevent its accomplishment for airplanes identified as Group 3 airplanes. Boeing then identified additional findings for all affected groups specified in Boeing Alert Requirements Bulletin 757- 29A0071 RB, Original Issue, dated November 16, 2023, that included errors that would allow actions that could introduce new hazards. The FAA assessed the new hazards and, although quantitatively assessed to be relatively low risk, determined that the new hazards could affect the operation and thus availability of the PTU.

The PTU is required to operate as a safety system backup; therefore, the new hazards that could be introduced as a result of the errors in Boeing Alert Requirements Bulletin 757-29A0071 RB, Original Issue, dated November 16, 2023, are a safety concern. This SAIB is considered an interim action to bring attention to this issue and recommend actions prior to the issuance of the AD supersedure. The FAA intends for the AD supersedure to provide credit for those airplanes that have complied with the Original Issue of the Requirements Bulletin and the provisions provided in certain alternative methods of compliance (AMOCs) that address the unsafe condition caused by the errors in the Original Issue of the Requirements Bulletins such that no additional work may be required.

To address this concern, Boeing issued Information Notices 757-29A0071 IN 01, dated May 1, 2024, and 757-29A0071 IN 02, dated May 2, 2025, and Boeing Fleet Team Digest 757-FTD-29-20001, “PTU Control Valve Failure.” The Information Notices clarify that there are errors in the existing Requirements Bulletins and recommend that operators determine which deviations are applicable to their fleets and to contact Boeing to verify if an AMOC may be needed. The Fleet Team Digest clarifies the details of the errors in the Requirements Bulletins. Boeing also plans to revise Boeing Alert Requirements Bulletin 757-29A0071 RB, Original Issue, dated November 16, 2023, to correct the errors.

Recommendations

The FAA recommends that all owners and operators of the affected airplanes review the information in Boeing Information Notices 757-29A0071 IN 01, dated May 1, 2024, and 757-29A0071 IN 02, dated May 2, 2025, and Boeing Fleet Team Digest 757-FTD-29-20001, “PTU Control Valve Failure,” and accomplish the actions included therein at the earliest opportunity.

For Further Information Contact

Katherine Venegas, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5353; email: katherine.venegas@faa.gov.

For Related Service Information Contact

Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Boulevard, MC 110-SK57, Seal Beach, CA 90740-5600; phone: (562) 797-1717; website:

https://www.myboeingfleet.com.