What happened
While performing a coupled Instrument Landing System (ILS) approach to runway 35, the aircraft experienced significant flight instrument deviations at approximately 100 feet above decision height. The localizer bar moved hard to the right, and the glide slope flag appeared, causing the aircraft to execute a sharp right turn.
In an attempt to correct the deviation, the pilot applied left yoke input just as the localizer bar swung hard to the left. The aircraft responded to this input and continued in a descent. As the pilot attempted to counter the movement with opposite yoke while searching for the autopilot disconnect button, the aircraft struck a light pole. This impact occurred approximately 1.5 miles off the departure end of runway 35. The collision caused substantial damage to the left wing spar and the nose landing gear wheel assembly.
The investigation
An examination of the ILS by the FAA determined that the glideslope equipment was out of service. However, the investigation confirmed that the localizer, outer marker, and middle marker equipment were all operational at the time of the incident.