Flight Narrative
While operating under instrument flight rules (IFR) at night, the pilot informed air traffic control that he had lost the alternator and had switched to the standby generator. He requested a lower altitude due to being in clouds and having lost cockpit lighting. Subsequently, he reported the loss of his compass and sought a clear area. The controller attempted to provide no-gyro vectors to the nearest airport.
The pilot then noted various problems with flight instruments, including the altimeter, and stated uncertainty about his ability to maintain straight and level flight. He later reported that the altimeter was functioning again but that he had lost the vacuum pump. He told the controller that he did not know his position and that the bank indicator, directional gyro (DG), and horizontal situation indicator (HSI) were providing conflicting information.
Over the following minutes, the pilot could not maintain the headings provided by the controller or consistent altitude profiles. His final transmission indicated that he was descending and attempting to pull up.
Radar Data
Radar tracking showed a series of 360-degree left turns, followed by turns to the right. The last left turn was computed to have a load factor of +5.487 g with an 80-degree angle of bank. The first right turn exhibited a load factor of +4.213 g and a bank angle of 76 degrees.
Structural Separation
During the event, the vertical stabilizer, horizontal stabilizers, and the outboard section of the right wing separated from the aircraft in flight.
Training Background
The pilot had attended recurrent Cessna 210 flight and simulator training the day before the accident. He failed to meet course standards for IFR proficiency, routinely lost control of the aircraft during training, and declined further IFR training.
Standby Generator Capabilities
The standby electric generator powers the turn coordinator but does not supply power to gyro slaving, cabin lights, HSI information, heated pitot tube, or the autopilot.