The 30-deg. intercept angle met the proper approach course intercept standards required by FAA procedures; however the “129 radial” phraseology is more typically used as part of an ATC instruction related to VORs. The Topeka VOR was located 5 mi. northeast of the airport. The TOP VOR 129 radial was parallel to the localizer back course, but 5.5 nm northeast of it.
Investigators said the Topeka VOR and the TOP 129 radial were not used to define the final approach portion of the localizer back course 31 procedure, but the VOR is used as part of the missed approach procedure. Radar data showed that upon the pilot accepting the approach clearance, the airplane continued on the 340-deg. heading across the localizer back course. The airplane then turned to approximately 309 deg., the inbound heading for the back course localizer procedure on reaching the vicinity of the TOP VOR 129 radial and well north of the final approach course for the localizer.
At that time, the controller noted the pilot's apparent deviation from the localizer procedure and instructed him to fly a heading of 280 deg. “to intercept the 129 radial for the back course.” The heading took the airplane back to the correct final approach course. The pilot intercepted the correct course at POACH, the final approach fix for the approach located 3.9 nm from the runway. The airplane at that time was at 2,900 ft. MSL. The published crossing altitude at POACH was 2,200 ft. The pilot executed the missed approach shortly afterward.
The Safety Board had yet to issue a determination of probable cause as we went to press. Certainly, decision-making, workload considerations and airplane handling will all be factors — in short, all the elements of airmanship regardless of how we define it.