The Federal Aviation Administration (FAA) has proposed two major airworthiness directives targeting Boeing’s long-haul flagship jets—the 787 Dreamliner and the 777—after identifying potential risks linked to critical flight control and hydraulic systems. The measures would affect more than 500 aircraft operated by U.S. carriers and aim to address hardware and software issues that could compromise flight safety if left uncorrected.
The FAA said the proposed directives cover 165 Boeing 787s and 340 Boeing 777s registered in the United States. The 787 order focuses on replacing potentially faulty mode control panels (MCPs), while the 777 directive requires airlines to install redesigned main landing gear pumps following a wheel well fire.
787 Safety Directive Targets Altitude Control Malfunction
The FAA’s proposed directive for the Boeing 787—covering all -8, -9, and -10 variants—comes in response to reports of “uncommanded altitude changes” caused by faulty MCPs manufactured by Honeywell. The issue, regulators said, stems from “software malfunctions and electrical power irregularities” that can result in erroneous altitude adjustments.
“Airlines operating Boeing 787 jets from U.S. hubs are being asked to replace mode control panels (MCP) following reports of uncommanded altitude changes,” the FAA stated.
Boeing 787 aircraft based at major airports including Seattle-Tacoma International (SEA) and Boston Logan International (BOS) are among those affected. According to the FAA’s notice, the uncommanded changes could lead to serious hazards, including “controlled flight into terrain or traffic conflicts” if the malfunction is not corrected.
The agency is directing operators to comply with Boeing’s April 2025 service bulletin, which outlines the replacement process for the MCP units. Each aircraft replacement is expected to cost about $405,000, although the FAA noted that Honeywell “may cover part of this expense under warranty.”
The proposed rule will be open for public comment for 45 days following November 17, allowing airlines, manufacturers, and maintenance organizations to submit feedback before finalization.
777 Fleet Faces Landing Gear Pump Overhaul
The FAA also issued a separate proposed directive for the Boeing 777, following an incident involving a wheel well fire linked to an overheating alternating current motor pump (ACMP). The event prompted safety investigations that revealed missing hardware and faulty electrical protections in the landing gear’s hydraulic pump system.
According to the FAA, “Boeing 777 operators must replace main landing gear pumps after a wheel well fire raised safety concerns.”
Investigators found that a missing lock washer and nut in the electrical load control unit allowed “two-phase power to reach the pump,” resulting in overheating and hydraulic fluid leakage—conditions that significantly increased the risk of onboard fire.
To mitigate the risk, Boeing issued a service bulletin on September 11, advising operators to inspect maintenance records and replace the ACMPs with a modified version featuring fusible links designed to prevent overheating. The FAA’s proposed directive would make this inspection and replacement mandatory for all U.S.-registered Boeing 777s.
“Boeing issued a service bulletin on 11 September recommending operators inspect records and replace ACMPs with modified pumps that include fusible links to prevent future overheating,” the agency said.
As with the 787 directive, the FAA is seeking public comments before final adoption of the rule.
Industry Reaction and Broader Safety Implications
The proposed directives reflect the FAA’s continued focus on strengthening oversight of both electronic flight control systems and mechanical components in commercial airliners. While the replacement costs and maintenance downtime may be significant, aviation safety experts view the measures as necessary steps to prevent future in-flight incidents.
“These directives reflect growing attention to both electronic and mechanical safety systems in commercial aviation,” the FAA noted in its summary. “Airlines must act swiftly to implement repairs to avoid potential incidents and comply with regulatory requirements.”
Industry analysts say the dual directives are part of a broader pattern of proactive FAA oversight following several high-profile safety reviews across U.S. fleets in recent years. The cost of compliance, while substantial, is expected to be outweighed by the operational and reputational risks of safety-related failures.
“While costs are significant, the directives aim to protect passengers, crews, and the broader aviation network from preventable hazards,” the FAA stated.
Strengthening Oversight Across Boeing’s Fleet
The proposed actions underscore the FAA’s effort to ensure continued safety and reliability in Boeing’s widebody fleet, which forms the backbone of many U.S. airlines’ international networks.
“The FAA’s twin directives targeting the Boeing 787 and 777 fleets highlight the importance of proactive maintenance and regulatory oversight,” the agency said. “By replacing faulty MCPs and ACMPs, operators reduce risks of altitude errors and wheel well fires, enhancing overall flight safety.”
Both directives remain open for public comment through the end of the year. Once finalized, airlines will be required to comply with the service bulletins within specified timeframes to maintain airworthiness certification.
The FAA’s proposals serve as a reminder of the critical balance between technological complexity and safety assurance in modern aviation—a balance regulators are determined to maintain.
Both directives remain open for public comment, giving industry stakeholders a chance to provide input before final rules are enacted.
