The Federal Aviation Administration has issued an urgent airworthiness directive requiring inspections of specific Boeing 787 Dreamliner aircraft. The order addresses a safety concern where defective sealant inside the fuel tanks could create a spark during a lightning strike, potentially leading to an explosion.
The directive, published in the Federal Register on November 2, becomes effective on December 7. It targets specific 787-8, 787-9, and 787-10 models identified by Boeing. The FAA stated that the sealant in the center wing fuel tanks of certain aircraft may not have received the required visual and adhesion inspections during manufacturing. Boeing was unable to provide records confirming these checks were completed.
Scope of the Boeing 787 fuel tank directive
The order covers 60 aircraft registered in the United States. US airlines collectively operate more than 170 Dreamliners, but the directive specifically impacts 17 of the US-registered airframes. United Airlines holds the largest fleet with 97 Dreamliners, followed by American Airlines with 70, and Alaska Airlines with six. Additionally, ch-aviation data indicates that 13 US-registered aircraft are operated by Aeromexico and 16 by Avianca.
The total number of affected aircraft globally could be higher. Many 787s operated by foreign airlines fly under US registrations. If other aviation authorities adopt similar measures, dozens of overseas-registered Dreamliners may also require checks.
Boeing maintains that the 787 features multiple layers of protection against lightning. However, the FAA emphasized that the composite materials used in the Dreamliner make lightning protection particularly critical. The agency warned that an ignition source within the fuel tank volume could result in a fuel tank explosion during a lightning strike event.
Inspection requirements and costs
Airlines must inspect the sealant in the left, right, and center sections where the wings meet the fuselage. The checks also include adhesion tests covering the area from the side-of-body rib to rib two. Operators must perform any necessary repairs if defects are found.
The FAA estimates the inspection will take 34 work-hours per aircraft, costing approximately $2,890. This totals $173,400 for all 60 US-registered jets. These figures do not include potential repair costs, though Boeing has indicated that some expenses might be covered under warranty.
Fuel tank explosions from lightning are extremely rare in modern aviation. The most notable incident occurred in December 1963, when Pan Am Flight 214, a Boeing 707, crashed after lightning ignited fuel vapor in a reserve tank, killing all 81 people on board. Manufacturers must design and test aircraft to prove that a lightning strike cannot ignite fuel vapor inside the tanks.
This mandate adds to a series of FAA interventions in 2026 regarding production issues with the Dreamliner. An August directive required wing inspections on nearly 80 787s worldwide, and earlier checks focused on cargo barrier fittings. Boeing has delivered more than 1,100 Dreamliners since the type entered service in 2011.
Source: Simple Flying
