Key Points:

  • The FAA mandates immediate inspections of all Boeing 747 variants due to accelerated degradation in lightning-protection components.

  • The directive, effective in 16 days, requires swift action: inspections within 90 days for passenger models and 120 days for cargo variants, to be repeated annually.

  • This measure, prompted by Boeing's reports of failures and cracks in 747 engine fuel systems, aims to prevent potential fuel tank explosions due to lightning strikes.

FAA Orders Swift Inspections on 747s for Lightning Protection

The Federal Aviation Administration (FAA) has issued an airworthiness directive, effective in 16 days, for airlines to inspect the lightning-protection systems in all Boeing 747 variants. This urgent directive comes after Boeing reported that the components designed to shield the engine fuel systems from lightning strikes were deteriorating faster than anticipated. Airlines are required to conduct initial inspections within 90 days for passenger 747s and 120 days for cargo models, followed by annual checks thereafter. The directive affects 211 U.S.-registered 747 aircraft, ranging from the earliest -100 models to the latest -8 variants.

This decisive action by the FAA, issued as a final rule bypassing the usual proposal stage, underscores the serious nature of the risk. The FAA's directive states that the evidence of compromised lightning protection features presents an immediate safety concern, necessitating rapid compliance.

Boeing's Support and Airlines' Compliance

Boeing supports the FAA's immediate rule, having already advised airlines to conduct inspections through "Multi Operator Messages" issued on 13 November. The company is actively communicating with the FAA and airline customers about this critical safety matter. According to Boeing, several operators have already commenced the two to three-day inspection process following its recommendations.

At the core of the safety issue are the "bonding jumpers," components designed to safely conduct electricity and prevent sparks within the fuel tubes penetrating the 747 fuel tanks. Boeing's investigations revealed an alarmingly high failure rate of these components, including a complete crack found in a fuel feed fitting encapsulation of a 747-8, meant to isolate potential sparks from lightning strikes.

The FAA emphasizes that undetected failure of these lightning protection features could lead to a scenario where no protection remains, posing a significant risk. A lightning strike, in the presence of flammable fuel vapors, could potentially trigger a catastrophic fuel tank explosion.

This directive continues the FAA's longstanding efforts to prevent fuel tank ignitions, a focus that intensified following the tragic explosion of TWA Flight 800, a Boeing 747-100, in 1996. Atlas Air Worldwide Holdings, UPS, Kalitta Air, and National Airlines are among the U.S. carriers with substantial 747 fleets, contributing to the global count of 495 747s currently in service or storage.