The US Federal Aviation Administration proposes to fine Everett, Washington-based Aviation Technical Services (ATS) $1.1 million for making improper repairs on 44 Southwest Airlines Boeing 737-300s.

ATS allegedly failed to accomplish work required under an airworthiness directive that mandated five repetitive inspections and a one-time inspection to find and repair fatigue cracks in the fuselage skin of the aircraft, said FAA. Those inspections were also required under the Southwest continuous airworthiness maintenance programme.

FAA also stated after the inspections ATS failed to install fasteners in all the rivet holes within the time specified for the task. The aircraft involved returned to service between 1 December 2006 and 18 September 2009.

The agency emphasised the Southwest 737-300 that suffered a fuselage crown failure in April of this year was not one of the 44 aircraft subject to the civil penalty.

FAA's latest proposed fine against ATS follows a previous penalty levied against the maintenance services provider in November 2010. At that time the agency fined ATS $530,250 after it determined ATS deviated from required procedures on fuselage skin crack inspections on 14 737s operated by Southwest.

Southwest 737-300

Source: Air Transport Intelligence news