UPS failed to implement detailed inspection procedures that might have prevented the catastrophic engine failure that downed one of its cargo planes last summer, killing 15 people, according to newly released documents cited by WUKY 91.3 FM.

The inspection requirement, which Boeing had recommended to the airline years before the incident, focused on a critical component that ultimately failed and allowed the engine to detach from the aircraft. The documents indicate UPS never adopted the more rigorous inspection standards despite the manufacturer's guidance.

The crash occurred when the engine disengaged mid-flight, resulting in a loss of control and subsequent impact near Louisville, Kentucky. All 15 people aboard the cargo jet — which operated a freight route for the shipping company — were killed in the accident.

The revelations raise questions about oversight of airline maintenance practices and manufacturer recommendations. Federal aviation regulators have long encouraged carriers to follow equipment makers' guidance, though such recommendations are not always mandatory unless formally adopted into certification requirements.

The incident has drawn scrutiny from aviation safety advocates and federal investigators, who have been examining whether UPS adequately maintained the aircraft and adhered to manufacturer specifications. The detailed findings from the investigation highlight the potential consequences when airlines do not fully implement preventive maintenance measures suggested by aircraft manufacturers.

The newly released documents suggest that more frequent or thorough inspections of the component in question could have identified the defect before it caused catastrophic structural failure. Investigators have been examining maintenance logs and inspection records to determine if earlier detection was possible under the procedures UPS had implemented at the time of the accident.