In-Flight Breakup Due to Pilot Incapacitation and Hypoxia (N2336V)

Flight Progression and Loss of Contact The aircraft was cleared direct and to climb to 14,000 feet. During the climb, the controller inquired several times about the flight's altitude. The pilot's responses were exactly 10,000 feet lower than the radar indications. The controller eventually instructed the pilot to stop altitude squawk, which was complied with. In the last communication, the pilot reported being level at 14,000 feet. For the next approximately 45 minutes, the aircraft proceeded generally toward its destination. When the controller observed the flight track turn approximately 45 degrees to the right and head generally northwest, attempts to contact the pilot were unsuccessful. The track then turned about 90 degrees to the left for a few minutes, followed by a 180-degree turn to the right. The aircraft dropped from radar coverage shortly after.