Southwest flight to Oklahoma City triggered low-altitude flight alert

US aviation authorities are currently investigating after a Southwest Airlines flight triggered an alarm while flying low.

The Federal Aviation Administration (FAA) said the alarm was triggered when a flight from Las Vegas came within nine miles (14.5 kilometers) of Will Rogers World Airport in Oklahoma City.

The incident occurred shortly after midnight on Wednesday.

Data from flight tracking website FlightRadar24 showed the plane came within about 500 feet (150 meters) of the ground.

An automated system called Minimum Safe Altitude Warning warns air traffic controllers when an aircraft is flying too low.

On an air traffic recording, an air traffic controller can be heard saying: “Southwest 4069, low level alert. Everything OK out there?”

The FAA did not provide information on how close the plane came to the ground, and the pilot’s reaction was not available on the audio recording, but FlightRadar24 estimated, based on atmospheric and flight data, that the plane came to within about 525 feet of the ground.

The plane landed safely shortly afterwards.

Southwest said in a statement on Friday that it was in contact with the FAA “to understand and resolve any irregularities in the aircraft’s approach to the airport.”

The FAA is also investigating a Southwest Airline flight that came within about 400 feet of the ocean in bad weather off the coast of Hawaii in April.

The pilot of that plane missed a landing at Lihue Airport and inadvertently caused a rapid descent, a company memo said. The plane, a Boeing 737 Max 8, returned to Honolulu. No one was injured.

In May, a Southwest flight en route from Phoenix to Oakland experienced a “Dutch roll” – a potentially dangerous sideways movement across two axes.

No one was injured, but the plane, also a Boeing 737 Max 8, was damaged. The National Transportation Safety Board is currently investigating.

The aircraft involved in the Oklahoma incident was a Boeing 737-800 and not a Max 8 model.