Southwest Airlines on Monday morning said it found subsurface cracks in two Boeing 737s, days after a similar plane was forced to make an emergency landing after it experienced an in-flight fuselage rupture.
The incident happened between 3.30 p.m. MST and 4 p.m. MST on Friday when Southwest Airlines Flight 812, a Boeing 737-300, suffered a rapid decompression and declared an emergency. A hole in the top of the aircraft, approximately mid-cabin, was clearly visible.
The captain of the aircraft immediately carried out a rapid but controlled descent from 36,000 feet to 11,000 feet when the incident occurred, and oxygen masks were deployed. A total of 118 passengers and 5 crew members were on board, and the plane safely landed at Yuma International Airport in Arizona. It was originally scheduled to fly from Phoenix, Arizona to Sacramento, California.
As a result of the incident, Southwest Airlines decided to ground 79 aircraft which are in the same sub-fleet of Boeing 737s, resulting in the cancellation of hundreds of flights throughout the weekend.
By late Sunday afternoon, 19 of the aircraft had undergone what the Dallas-based airline called an “intense” inspection with no findings. Those 19 aircraft were then returned to service.
In two other airplanes, however, Southwest Airlines said the inspection found small, subsurface cracks in the Boeing 737-300s. “Further evaluation and potential repairs will be necessary before those planes are returned to service,” a statement said.
NTSB press briefing on Southwest Flight 812
Inspections of the remaining 58 aircraft are expected to take place through late Tuesday in cooperation with Boeing. Southwest Airlines said the inspection involves a non-destructive test in the form of High-Frequency Eddy current of the aircraft skin. This test is designed to detect any subsurface fatigue in the skin that is not visible to the eye.
As of Sunday, Southwest Airlines said approximately 300 flights had been canceled as a result of the inspections.