CNN is reporting that United Airlines abruptly decided to ground 96 Boeing 757s in order to perform maintenance checks relating to the aircraft’s air data computer system.
As a result, United will have to cancel or delay some of its flights Tuesday night and Wednesday morning.
The Federal Aviation Administration said United’s action involves its compliance with an airworthiness directive issued in 2004 that required a modification to the air data computer system to ensure that flight crews would be able to stop an overspeed or stall warning that sounded in error.
According to United spokesperson, Rahshaan Johnson, the voluntary inspections take anywhere from 60 to 90 minutes per aircraft meaning the fleet should be operational again within 24 hours.
Although the inspections were voluntary and not mandated by the FAA, the urgency of the grounding stemmed from the fact that United upgraded the computers in 2004 when the FAA mandated the change but had never actually checked to ensure that their upgrades were in compliance.