A minor overhaul of the Boeing 737 MAX production process resulted in a minor electrical problem that temporarily landed more than 60 aircraft on Friday, nearly 200 MAXs back in service since December.
While this latest manufacturing flaw has nothing to do with the flight control system associated with the two fatal crashes that grounded the MAX for nearly two years, it slows down the positive momentum that began to build as more MAXs were out. coming air օդ new orders are coming. United, Alaska և Southwest.
The problem, to the knowledge of the two modified production processes, arose when the backup power control unit was attached to the flight deck rack in place of previously used anchors.
This change was made in such a way that it did not provide a complete way of electrifying the unit. Lack of safe electrical grounding can cause malfunctions in a number of electrical systems, such as the engine antifreeze system and the tailpipe.
Boeing said it had identified the problem “on a production aircraft during normal construction operation” and that checks were needed to verify that there was “sufficient land route” for the control unit.
The Federal Aviation Administration (FAA) announced that Boeing announced late Thursday night that it was recommending the temporary removal of certain MAX aircraft from service.
After announcing to Boeing late Thursday night, Southwest based its MAX 30. The American substantiated 17 and United 16.
Boeing said 16 customers were affected worldwide.
On Friday, it was unclear whether such a seemingly harmless change in production should have required FAA approval.
Boeing spokeswoman Essica Koval declined to comment on Friday, saying the company would share additional information with airlines as soon as it became available.
Another 737 stabilizer problem
This last issue adds to the longevity of the wrong steps that Boiling is currently suffering from.
Manufacturing defects have justified more than 807 large-scale 787 Dreamliners over the months; The design flaws mean that the Air Force KC-46 military air fuel refueling system needs to be completely redesigned. Quality issues have delayed the Starliner spacecraft program.
And in the case of a previously unreported problem, Boeing recently discovered a potential batch defect of 20 to 40 engines moving the horizontal stabilizer on all 737s, including the MAX and earlier models.
This engine, manufactured by Eaton and headquartered in Ireland, is part of a system that raises the nose of the aircraft up or down. Boeing said that seven of the aircraft with a stabilizing engine from a defective batch are MAX.
Boeing’s Kowal said the defect could affect the reliability of the component.
The engine “has already been replaced in five of the MAX, and the other two aircraft will be replaced before they can be flown again,” he said.
Koval said Boeing continues to “assess any potential impact on the 737 NG fleet.”
Sarah Yantz, a spokeswoman for American Airlines, said the engines of the two MAX cars in her fleet had been replaced as a result of a Boeing order, although neither had a problem. (Both of these fixed MAXs are now based on the issue of a new power management unit).
Stabilizer motor failure is a rare flight problem. Doing so requires that pilots use the hand wheel in the cockpit to clear the height of the aircraft.
Coincidentally, there was a flight stabilizer problem last week that required manual upgrades to get the 737 MAX home safely, but for a different root cause.
On March 29, American Airlines 737 MAX, flying from Miami (Flas.) To Santo Domingo, Dominican Republic, with 135 passengers and 6 crew members, was forced to retreat when the horizontal stabilization system failed.
The pilots conducted the stabilization checklist, cut the aircraft by hand and made a safe landing as soon as they returned to Miami.
This incident was not related to the Maneuver Performance Enhancement System (MCAS) flight control software involved in two MAX crashes. Nor was the problem with the recently discovered stabilizer engine.
The American Airlines Jantz said that the fault this time was in the electrical relay switch that controls the motor of the stabilizer. The American then replaced the relay switch.
When FAA Administrator Steve Dixon signed the order outlining the way back to MAX service, he noted that common problems during the flight would probably be a cause for concern for MAX.
“It is inevitable that at some point in the future the Boeing 737 MAX will return to the airport of its origin, deviate or land at its destination with a real or suspicious flight problem,” Dixon said at the time. “While these events can be uncomfortable and disturbing for travelers, they happen almost every day.”
US airlines are dealing with the latest issue
However, Boeing’s large build-up of design and quality issues over the past two years has severely damaged its reputation for technical excellence.
The production change, which caused the last problem of the electrical system for MAX, took place after the initial grounding of the jet in March 2019, so only the aircraft built after that are affected. Southwest has 28 MAXs without this problem, United has 14s, and American 24s – all are still flying.
On Friday, Chris Hurrell, captain of the US Navy 737, told airline pilots that his MAX fleet had “no abnormalities” as a result of a change in production.
However, the CEO of the American company David Seymour told the staff in a memorandum that “we temporarily decommissioned those 17 planes in the direction of Boeing.”
Seymour said substantiating the 17 MAXs would lead to “operational challenges: crew members, customers – aircraft conversions, schedule changes – support for our customers.”
United said it was “working on aircraft exchanges to minimize the impact on our customers,” cooperating with Boeing and the FAA to “determine the additional steps needed to ensure that these aircraft meet our strict safety standards.” »:
Southwest spokesman Brandi King said the airline also “did not have any known operational challenges with the issue”.
And since Southwest currently operates a limited MAX flight schedule of 44 flights per day, with no more than 15 flights per day, it expects “minimal downtime as we have spare aircraft in our system.”
Reasoned MAXs have no schedule to return to service yet.
“It’s too early to estimate the time,” King said. “We look forward to further correction from Boeing.”