United Airlines says it expects “minimal disruption” today resulting from its grounding of its 96 Boeing 757s after a check of maintenance records showed that the airline did not fully comply with a 2004 FAA Airworthiness Directive. A United spokesman told AIN today that the groundings resulted in about 15 flight cancellations, mainly last night.

The AD in question called for software upgrades and replacement of certain components in the airplanes’ air data computer systems to allow pilots to silence erroneous overspeed or stall warnings. United recently found that it hadn’t completed all the necessary function checks after performing the modifications in 2004. The spokesman said the airline expects to finish all the checks, reported to take between 60 and 90 minutes, today.