FAA orders Boeing 787 fuel tank sealant inspections after lightning risk

The US Federal Aviation Administration (FAA) has ordered inspections of certain Boeing 787-8, 787-9 and 787-10 Dreamliners over concerns about fuel tank sealant in the centre wing tank, according to AeroTime. The airworthiness directive was published on 2 November 2026 and takes effect on 7 December 2026. The FAA estimates that 60 US-registered aircraft are affected.

What the directive addresses

The FAA found that required manufacturing checks of the sealant were either not completed or could not be verified. The sealant installations inside the centre wing fuel tank lacked evidence of the required visual and adhesion inspections during production. The agency warned that defective sealant could allow an ignition source to develop inside the tank during a lightning strike, potentially igniting fuel vapour. In the directive, the FAA said the unsafe condition could result in "a risk of a fuel tank explosion during a lightning strike event".

What operators must do

Operators must carry out detailed inspections of sealant installations in the left, right and centre wing side-of-body areas, including sections between the side-of-body rib and rib 2. The work covers checks for sealant defects, surface depressions and inadequate adhesion. Any defects found must be fixed using approved repairs. The required work follows a Boeing requirements bulletin issued on 5 November 2025.

The FAA estimates the inspections and adhesion tests will take about 34 hours per aircraft, at a cost of $2,890 each. That puts the total for the 60 US aircraft at $173,400, excluding repairs. The agency said it did not have enough information to estimate the cost of any corrective work, and some costs could be covered under Boeing's warranty.

Comments on the proposal

The directive follows an FAA proposal published on 24 February 2026. Boeing and American Airlines both requested changes to the repair requirements during the comment period. Boeing asked that repairs be allowed under existing approved procedures rather than needing separate approval each time, and the FAA agreed. American asked for clarification on where the sealant must be tested and whether existing Boeing repair procedures could be used. The FAA clarified the inspection areas and allowed those procedures.

The Foundation for Aviation Safety asked whether Boeing was now carrying out the sealant inspections during production. The FAA said the directive covers aircraft for which there was insufficient evidence that inspections had been done, and confirmed the inspections are being performed in production on aircraft outside its scope.

What this means for travellers

The sources do not report any flight cancellations or schedule changes. The inspections take about 34 hours per aircraft, so affected jets will need to spend time out of service, which could in principle affect aircraft availability on routes that use the 787. AeroTime does not say which airlines operate the 60 US-registered aircraft, apart from American Airlines having commented on the proposal. The directive applies to US-registered aircraft in the FAA's estimate, and the sources do not say how many aircraft worldwide are covered. Passengers with bookings on a 787 should check with their airline if they are concerned about disruption.

Sources: AeroTime