According to a Federal Aviation Administration press release on April 4, the FAA is issuing an emergency directive on April 5. Operators of certain Boeing 737 models must immediately carry out electromagnetic inspections for metal fatigue.
Southwest Airlines Flight 812 was en route from Phoenix to Sacramento on April 1 when the cabin depressurized. A hole had opened in the top of the aircraft. The flight landed safely in Yuma, Arizona. One flight attendant was injured, but not seriously, according to a statement from Southwest.
The airline is inspecting its Boeing 737s. Subsurface cracks were found in two of them, the airline stated.
Metal fatigue is thought to have caused the hole to form. Investigations are not complete.
There are 175 Boeing aircraft in use around the world, and 80 of those are operated in the United States by Southwest Airlines.
According to the FAA’s press release, Transportation Secretary Ray LaHood said, “Safety is our number one priority….Last Friday’s incident was very serious and could result in additional action depending on the outcome of the investigation.”
Inspectors must use electromagnetic, or eddy-current, technology in parts of aircraft fuselages which cannot be inspected visually. This will apply to Boeing 737 aircraft that have accrued over 30,000 flight cycles, and are in the -300, -400, and -500 series, according to a statement from the FAA.