Manufacturing flaw likely as flight window, piece of fuselage rip away 6 minutes after takeoff

PORTLAND (US): Alaska Airlines grounded all of its

Boeing 737-9 MAX

aircraft late Friday, hours after a window and piece of

fuselage

on one such plane blew out in midair and forced an

emergency landing

in Portland, Oregon.
After Friday's blowout, the Federal Aviation Administration (FAA) on Saturday ordered US airlines to stop using some Boeing 737 Max 9 planes until they are inspected.

The order will affect about 171 planes.
Friday's incident occurred shortly after takeoff and the gaping hole caused the cabin to depressurize. Flight data showed the plane climbed to 16,000 ft before returning to Portland International Airport. The airline said the plane landed safely with 174 passengers and six crew members. The plane was diverted about about six minutes after taking off at 5.07pm, according to flight tracking data from the FlightAware website. The pilot told Portland air traffic controllers the plane had an emergency, was depressurized and needed to return to the airport, according to a recording made by the website LiveATC.net.
The fuselage section that ripped away from the Boeing jet midflight reflects a design feature in use for many years, suggesting investigators are likely to zero in on quality issues rather than a design flaw.

The Max 9 aircraft was built with a modular cutout in the frame that can house an emergency exit. Some airlines order planes with the doors installed to maximize the number of seats. Others, like Flight 1282 operator Alaska Airlines, don't require the extra exits and have the holes permanently plugged up. From the inside, a plug is undistinguishable from the sidewall on the aircraft, while on the outside, an outline of the opening can be seen. The Boeing 737 cutouts date back to the mid-2000s, and hundreds have been installed.

"This has all the earmarks of a manufacturing deficiency, a quality escape from Boeing," said aviation safety expert Jeff Guzzetti, the former FAA accident investigation chief.
Cutouts like the one in the Alaska Air incident are aimed at increasing production efficiency. They allow manufacturers to make one standard fuselage section, instead of different designs for various airlines. This reduces cost, and facilitates changes later -- a low-cost carrier purchasing the aircraft second-hand would be able to restore the exit and add seats.