CEN10FA119

The pilot's failure to maintain airplane control during final approach.

A witness reported that the multi-engine turboprop airplane was on final approach to land when it suddenly veered to the left and entered a rapid descent. The witness stated that he heard the "whine of the engines" before the airplane impacted terrain about 1/2 mile south of the runway threshold. In the days preceding the accident flight, the airplane had been at a maintenance facility to resolve a vibration in the rudder system while the autopilot system was engaged. There were no anomalies reported with the autopilot system during a test flight completed immediately before the accident flight. However, anomalies with the rate gyro were noted by a mechanic who recommended replacing it, but the pilot departed on the accident flight without the recommended repair having been completed. Further, examination of the autopilot annunciator panel indicated that the autopilot was likely not engaged at the time of impact, likely because the airplane was on a short final approach for landing. Accordingly, any existing autopilot faults would not have affected the flight as the autopilot system was likely not in use. There were no failures identified with the primary flight controls, engines, or propellers that would have prevented the pilot from maintaining control of the airplane manually. Toxicological testing revealed the presence of Zolpidem in the pilot's blood (Zolpidem, the trade name for Ambien, is used for short-term treatment of insomnia); however, the reported levels would likely not have resulted in any impairment.

HISTORY OF FLIGHT On February 12, 2010, at 1355 Central Standard Time, a Piper PA-31T (Cheyenne II) turboprop airplane, N250TT, impacted terrain while on final approach to runway 33 at the Forest City Municipal Airport (FXY), Forest City, Iowa. The pilot was fatally injured. The airplane was registered to and operated by Mayes Aviation, LLC, under the provisions of 14 Code of Federal Regulations Part 91, while on an instrument flight plan. Visual meteorological conditions prevailed for the business flight, which departed the Spirit of St. Louis Airport (SUS), St. Louis, Missouri, at 1223. On the afternoon of February 9, 2010, the accident airplane arrived at FXY carrying passengers. Following that flight, the pilot reported to several individuals that he had experienced a vibration in the rudder system while the autopilot system was engaged. After a phone conversation with his mechanic, the pilot decided to reposition the airplane to SUS in order to have the autopilot system evaluated at a maintenance facility. The pilot told the airport manager at FXY that he would return on February 12, 2010, to retrieve his passengers. According to a flight tracking website, the airplane was repositioned from FXY to SUS later that same afternoon. The autopilot system was then examined by Aero Charter Jet Center (Aero Charter) over the next several days. According to statements provided by Aero Charter employees and the associated work order paperwork, the source of the rudder vibration was attributed to a faulty rate gyro which required the replacement of the device. However, due to inclement weather conditions, the replacement rate gyro was not delivered to Aero Charter by the morning of February 12, 2010. The pilot decided that he would fly the airplane without the rate gyro being replaced. The pilot signed a work declined form indicating that the rate gyro had not been repaired. The form also stated that the faulty rate gyro had an open signal path to the output-hi pin connector. Before departing the St. Louis area, the pilot and an Aero Charter avionic technician completed a test flight. The avionic technician reported that there were no anomalies with the autopilot system during the test flight. Following the uneventful test flight, the pilot requested that the airplane be topped-off with JET-A fuel and was observed in the pilot's lounge preparing for the accident flight. According Federal Aviation Administration (FAA) Air Traffic Control (ATC) documents, the pilot obtained an instrument flight rules (IFR) clearance to FXY. After departure, the flight was cleared to SCHMD intersection before resuming the OZARK 3 departure procedure. The flight was eventually cleared to flight level (FL) 240 and to proceed direct to FXY. At 1249, the pilot reported being level at FL240. At 1306, the controller approved the pilot's request to fly direct SCHUM intersection, which was an initial approach fix (IAF) for the area navigation (RNAV)/GPS Runway 33 instrument approach into FXY. At 1318, the flight was cleared to descend to FL200. At 1920, the flight was cleared to descend at the pilot's discretion to 12,000 feet mean sea level (msl). At 1327, the pilot established radio communications with Minneapolis Air Route Traffic Control Center (ARTCC) and advised that he had the current weather observation report for FXY. At 1330, the controller cleared the flight to 5,000 feet msl. At 1333, the controller approved the pilot's request to temporarily go-off the assigned ARTCC radio frequency. About one minute later the pilot reestablished radio contact with the controller and reported descending through 7,700 feet msl for 5,000 feet msl. At 1336, the controller approved the pilot's request for an altitude block between 7,000 and 9,000 feet msl in order to perform "a little autopilot correction." At 1339, the pilot reported descending through 7,000 for 5,000 feet msl. The controller then cleared the flight for the RNAV/GPS Runway 33 instrument approach into FXY and to continue the descent to 4,000 feet msl. At 1343, the airplane descended below available ATC radar coverage at 4,300 feet msl. The final radar return associated with the accident airplane was recorded at 1343:37 about 26 miles south-southeast of FXY. No additional flight track information was recorded for the remainder of the flight because the airplane remained below the available radar coverage for the area. At 1345, the pilot reported being established on the inbound approach and requested to descend to 3,000 feet. The controller approved the flight to descend to 3,000 feet and to change to the destination airport's common traffic advisory frequency (CTAF). The pilot replied that he had already checked in with the FXY CTAF and requested to remain on the ARTCC frequency so that he could cancel the flight plan with the controller before landing. At 1353, the pilot reported having the destination airport in sight. The controller cleared the flight for the visual approach into FXY; however, the pilot did not acknowledge that clearance or make any additional radio transmissions on the assigned ATC frequency. The airport manager at FXY was a witness to the accident. He reported that about 12 minutes before the accident, the pilot established radio contact on the common traffic advisory frequency (CTAF) and was provided the current weather and runway conditions at the airport. About 9 minutes later, the airport manager observed the accident airplane on final approach to runway 33. He stated that the airplane was on a "normal approach" when it suddenly "veered sharply left, making a rapid descent." He reported that he heard the "whine of the engines" and then a "loud thud." The airplane impacted terrain about 1/2 mile south of the runway threshold. PERSONNEL INFORMATION According to FAA records, the pilot, age 66, held an airline transport pilot certificate, issued on February 22, 2007, with single and multi-engine land airplane and instrument airplane ratings. The single-engine land airplane rating was limited to commercial privileges. The pilot was type-rated for the Cessna 500 (Citation) business jet. The pilot also held a flight instructor certificate, issued on February 5, 2008, with airplane single and multi-engine land ratings. His last aviation medical examination was completed on April 21, 2009, when he was issued a second-class medical certificate with a restriction for corrective lenses. A search of FAA records showed no previous accidents, incidents, or enforcement proceedings. The most recent pilot logbook entry was dated January 11, 2010. At that time, the pilot had accumulated 10,352 hours total flight time, of which 8,160 hours were as pilot-in-command. The logbook indicated that he had accumulated 3,189 hours in single-engine airplanes, 6,602 hours in multi-engine airplanes, 2,141 hours at night, and 1,306 hours in actual instrument conditions. The pilot had flown 253 hours during the past year, 144 hours during the prior 6 months, and 57 hours during previous 90 days. He flew an additional 34 hours in the accident airplane since the last logbook entry, according to an airplane flight log that was located in the wreckage. The pilot's most recent flight review and instrument competency check were completed in February 2008. The pilot received specialized instruction in the accident airplane, including 10 hours of flight instruction, when the airplane was acquired by his employer in October 2009. According to available information, he had flown 113 hours in the accident airplane since it had been purchased. AIRCRAFT INFORMATION The accident airplane was a 1978 Piper PA-31T (Cheyenne II) turboprop airplane, serial number (s/n) 31T-7820050. Two Pratt & Whitney model PT6A-28 turbine engines powered the airplane. The airplane was equipped with two constant speed, full feathering, McCauley model 4HFR34C766/94LNA-2 propellers. The pressurized airplane had a certified maximum takeoff