Bonanza 35
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 75; Flight Crew Total 947; Flight Crew Type 75
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Inflight Event / Encounter Loss Of Aircraft Control
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Diverted; Flight Crew Regained Aircraft Control; Flight Crew Became Reoriented; General Maintenance Action
Aircraft; Human Factors
While flying to LBE received vectors to ILS 23. Controller provided vectors just outside Zinta intersection. After loading approach and activating vectors to final I was cleared for the ILS 23 at or above 4;200 FT. As I approached the intercept to the ILS 23 the auto pilot failed to capture the ILS. While trying to determine issue the aircraft entered an unusual attitude. I disconnected the AP and recovered the aircraft from the unusual attitude. During the recovering I lost approximately 500 FT of altitude which triggered the Controller to state there was an altitude alert. I immediately climbed to 4;200 FT and tried unsuccessfully to capture ILS 23. After another attempt at the ILS 23 as well as GPS 23 I determined the Sandel HSI has not allowing the CRS pointer to be set to the correct course. I then requested to climb to 7;000 FT to get out of IMC and a direct heading to return. After returning I landed in VFR conditions. I scheduled a time to have the Sandel 3308 checked and the unit was found to have a course pointer malfunction.
BE35 pilot reports autopilot failing to capture the localizer during an ILS approach then entering an unusual attitude. The autopilot is disconnected and the aircraft returned to assigned altitude but the ILS is unsuccessful. A second attempt is also unsuccessful along with a GPS approach and the reporter returns to his home airport in VMC. The HSI is found to have a course selection anomaly.