The aircraft's most recent service involved adjusting the elevator control cable, and was performed two nights before the crash at a repair facility located at Tri-State Airport in Huntington, West Virginia. During the investigation, it emerged that the mechanic who worked on the elevator cables had never worked on this type of aircraft. Investigation revealed that turnbuckles controlling tension on the cables to the elevators had been set incorrectly, resulting in insufficient elevator travel, leading to the pilots not having sufficient pitch control. Although normally a post-adjustment control test would be conducted to ensure that the maintenance had been carried out correctly, and that the surface was operating properly, the maintenance supervisor who was instructing the mechanic decided to skip this step. The NTSB noted that the FAA was aware of "serious deficiencies" in the training procedures at the facility, but had done nothing to correct them.