US National Transportation Safety Board (NTSB) executive director Daniel Campbell has criticised the Federal Aviation Administration for promising to specify fuel-tank inerting requirements, but failing to do so.

The FAA says it is working on a fuel-tank inerting system notice of proposed rulemaking (NPRM), but it has been delayed by the complexities of deciding how to specify retrofit and installation.

Campbell has acknowledged progress on eliminating potential ignition sources near fuel tanks, but says an inerting system is needed which fills the space created in a tank as fuel is used with an inert gas such as nitrogen.

The NTSB has specified this requirement in its most-wanted improvements list for more than a decade – even before a fuel tank explosion brought down Trans World Airlines flight 800 in 1996, which gave impetus to the NTSB’s campaign.

The FAA insists that it will publish an NPRM on inerting, but will not give a timescale.

Source: Flight International