The Federal Aviation Administration released two new airworthiness directives (AD) which require the airlines to modify their Boeing 747s and Boeing 767s fuel tank monitoring systems in order to prevent the risk of ignition within the tanks.
The new directives apply for the following planes:
The FAA requires modifications to the Fuel Quantity Indicating System (FQIS). These modifications are to prevent the development of an ignition source inside the centre fuel tank, which is due to electrical fault conditions.
“The FAA is issuing this AD to prevent ignition sources inside the center fuel tank, which, in combination with flammable fuel vapors, could result in a fuel-tank explosion and consequent loss of the airplane,” reads both directives.
The directives affect 261 US-registered 767s (255 cargo airplanes, 4 private and 2 experimental airplanes) and 71 747s; different actions are required for cargo jets.
Airlines will have 72 months, after the effective date of this AD (10th November), to make the required modifications.