The US Federal Aviation Administration (FAA) has recently proposed an airworthiness directive (AD) regarding Boeing’s popular 777 family. Specifically, the government body wants the AD to result in 777 operators inspecting their triple-sevens for damage to their rivets. The proposal comes after a report found that certain 777s were missing their heads.
Potential rivet inspection for all 777s
Two days ago, on April 9th, the FAA submitted a proposed airworthiness directive relating to all active examples of Boeing’s widespread 777 family. For now, the proposal is amid a comment period. It explained its proposition by stating that:
“This proposed AD was prompted by a report that an operator found solid rivets with missing heads at the left buttock line 25 on the sloping pressure deck web. This proposed AD would require doing a detailed inspection of the left and right side sloping pressure deck at certain stations for any damaged solid rivets, and applicable on-condition actions.”
The FAA is inviting comments regarding the proposal to be sent by May 25th, after which the comment period will cease. The report upon which the US government body based its proposed AD related to a single 777-300 aircraft. However, it has since found that “four more 777-300s and one retired 777-200 [had] missing solid rivet heads.”
As such, it has proposed inspections of all operational 777s to address this issue, and to ensure that it does not worsen. Boeing reportedly found that the rivets in question were “inadequate for the complex tension loading environment,” which led to cracking and damage.
The FAA warned that “undetected damaged or missing rivet heads on the sloping pressure deck web” could lead to:
“…loss of sloping pressure deck panels, causing decompression and pressure loss, and loss of the hydraulic systems in the area for wheel brakes (both normal and alternate) and steering, and potentially leading to runway departure and adversely affecting the structural integrity of the airplane.”
Of course, this is not the first instance of the Boeing 777 being at the forefront of the FAA’s attention this year. Indeed, a United triple-seven suffered an engine failure over Denver, Colorado in February, causing parts to rain down on local suburbs.
Shortly afterward, the FAA lept into action and released an airworthiness directive pertaining to the aircraft type involved in the incident. However, unlike the new proposal regarding rivets that will require all aircraft to be inspected, this only concerned certain triple-sevens. Specifically, it affected Pratt & Whitney PW4000-engined models, of which there are 128 examples.
Recent proposal concerning the 737 MAX
Boeing’s narrowbody portfolio has also recently been the subject of a proposed FAA airworthiness directive. This concerned fuel quantity processor units (FQPUs) on certain variants of the company’s 737 MAX family, namely the MAX 8 and MAX 9.
The FAA reported that its proposed AD would “require installing a new FQPU, and doing an FQPU software check.” However, this proposal is also subject to a 45-day comment period. This will come to an end on May 17th.
Simple Flying contacted Boeing for comment, but did not receive a response by the time of publication. We will add Boeing’s statement upon receiving it.
What do you make of the FAA’s proposed airworthiness directive regarding the Boeing 777? Let us know your thoughts in the comments.