The FAA has finally decided that the wiring looms in the 737MAX are insufficient to meet current codes of acceptance and they will need replacing.
Boeing is said to be privately fuming over the decision but is adamant that the issue will not prevent production and return to service.
Boeing’s solution is to retrofit the existing undelivered MAX’s parked up before delivery, while wiring looms on grounded aircraft already delivered will be retrofitted over the next six months following return to service.
The wiring looms risk short circuiting and causing uncontrollable rudder responses.
However, Boeing says the 737-700/800/900 all have the same loom and regulations didn’t require them to be modified, because regulations have been changed since.
The FAA said the changes were made in 2012 and all new aircraft were required to meet the new requirements. Boeing ignored them.