NTSB Factual Report

HISTORY OF FLIGHT

On February 2, 2008, approximately 1713 central standard time, a Cirrus SR22, N824BJ, single-engine airplane, was destroyed when it collided with terrain while maneuvering near the Lindsay Municipal Airport (1K2), Lindsay, Oklahoma. The certified flight instructor and the private pilot were fatally injured. The airplane was registered to and operated by the private pilot. No flight plan was filed and visual meteorological conditions prevailed for the instructional flight conducted under 14 Code of Federal Regulations Part 91.

The flight instructor, who was also a Federal Aviation Administration (FAA) certified airframe and power plant mechanic (A&P), operated a maintenance facility from a private airstrip about 5 miles southeast of the Lindsay Airport. According to one of his customers, the instructor had called him on the day of the accident, and told him that he had completed the annual inspection on his airplane. The instructor planned to reposition it to Lindsay Airport, because he was already scheduled to be there to give the private pilot, whom the customer knew as well, a "biennial flight review." Later that day, the customer saw the accident airplane in the traffic pattern and drove to the airport. When he arrived, he saw the airplane departing to the north. The customer then drove over to a friend's hangar, picked him up, and drove to the departure end of Runway 10 so they could watch the airplane land. About 20 minutes later, he "heard an engine accelerate then a boom." The customer said that he had not seen or heard the airplane prior to the sound of the engine accelerating.

Another witness was in his backyard when he heard the airplane's engine "wind up hard." He said, "I turned to look at the plane, and it looked like it fell to the ground in a 45 degree angle - The plane disappeared behind a row of trees - then I saw a ball of smoke - then I heard it hit the ground." The witness also stated that he heard an airplane making "circles" around the airport before the crash but he was not sure it was the accident airplane. Several other people heard the airplane flying in the vicinity of the airport and reported hearing the airplane's engine "missing" or "cutting out."

Lindsay Municipal Airport is an uncontrolled airport and pilots communicate via a common traffic advisory frequency (CTAF). There were no reports that the pilots made any distress calls prior to the accident.

A review of radar data revealed a VFR target at an altitude of 1,700 feet mean sea level (msl) north of Lindsay Municipal Airport, at 1659. The target continued to track to the north before it made a left turn to the northwest and flew for approximately 15 miles. During this time, the target climbed to an altitude of 3,000 feet msl.

Approximately 1704, when the target was at an altitude of 2,800 feet msl it entered a left turn to the south. The target then descended to 2,700 feet msl, and then climbed to 2,800 feet msl, as it continued on a southerly heading.

At 1705, the target made a right, 360-degree turn at an altitude of 2,800 feet msl before it returned to a southerly heading.

At 1708, the target entered a left turn to the east-southeast at an altitude of 2,700 feet msl. The target was northwest of the airport and began to track toward the southeast. During this portion of the flight, the target climbed to an altitude of 2,900 feet and then began a steady descent as it approached the airport from the northwest before the data ended at 1712. At that time, the airplane was located approximately three-quarters of a mile northeast of the approach end of Runway 19, and was at an altitude of approximately 1,500 feet msl.

PILOT INFORMATION

The flight instructor held a commercial certificate for airplane single-engine land, and instrument airplane. He also held a certified flight instructor rating for airplane single-engine land, and instrument airplane. In addition, he was a certified airframe and power plant mechanic, with inspector authorization (IA). His last FAA second-class medical was issued on January 30, 2007. A review of his logbook's revealed that his last entry was made on October 30, 2007. At that time, he had accrued a total of 1,438.8 hours. There was no entry that he had any previous experience in the same make and model as the accident airplane.

The pilot held a private pilot certificate for airplane single-engine land, and instrument airplane. His last FAA third class medical was issued on January 17, 2008. A review of his logbook revealed that he had accumulated approximately 1,327 hours, of which 230 hours were in a Cirrus SR22 airplane.

AIRCRAFT INFORMATION

The airplane was a 2006 Cirrus SR22, serial number 2119, and was powered by a Teledyne Continental Motors (TCM), IO-550-N (42), serial number 689918 engine. A Hartzell PHC-J3YF-1RF/ FP4809B propeller was attached to the engine.

A review of the airframe logbooks revealed that the last annual inspection was completed on October 2, 2007, at an airplane total time of 155.7 hours. At the time of the accident, the airplane and engine had accrued a total of 198.3 hours.

METEORLOGICAL INFORMATION

Weather at Paul's Valley Municipal Airport (PVJ), approximately 20 nautical miles southeast of the accident site, at 1750, was reported as wind from 080 degrees at 5 knots, visibility 10 miles, clear skies, temperature 57 degrees Fahrenheit, dewpoint 37 degrees Fahrenheit, and a barometric pressure setting of 29.99 inches of Mercury.

WRECKAGE INFORMATION

The airplane came to rest in a pasture approximately .25-miles northwest of Lindsay Municipal Airport on a magnetic heading of approximately 240 degrees at a field elevation of 965 feet msl. A post-impact fire consumed the main wreckage of the airplane, which consisted of the cockpit, fuselage, tail section, left and right wings, main landing gear, and the engine.

The initial impact mark was about 45 feet from where the main wreckage came to rest. The initial impact mark included two horizontal impact marks (consistent with the leading edge of the wings) that expanded to the left and right of a 3- foot by 4- foot- wide crater. A piece of red navigational lens was found at the far most end of the right impact mark.

The three-bladed propeller and numerous pieces of Plexiglas were found imbedded in the initial impact crater. One blade exhibited an "S" bend. The second propeller blade exhibited leading edge damage and the third propeller blade was fractured at the blade root. This blade exhibited an "S" bend, and was bent toward the non-cambered side of the blade, beginning at the blade root.

The nose wheel, Cirrus Airframe Parachute System (CAPS), parachute rocket motor, engine cowling, and sections of airframe were found scattered along the wreckage path between the initial impact point and the main wreckage.

Examination of the airplane's safety equipment revealed that the CAPS activation handle was intact and in its holder, the rocket motor was expended, and the deployment pack consisted of a partially packed parachute (risers extended out of the bag). A portion of the front right seat's shoulder harness, including a deployed airbag, was found in the wreckage.

Flight control continuity was established for all flight controls from the respective surface to the cockpit. Examination of the flap actuator revealed the flaps were fully retracted.

The engine was examined at Teledyne Continental Motors on June 17, 2008, under the supervision of the Safety Board. Examination of the engine revealed that it had sustained impact and thermal damage, but all six cylinders remained attached to the engine. The left and right magneto exhibited impact and thermal damage; however, the left magneto was only partially attached to the engine. The spark plugs were removed. The number three top plug was damaged, but each of the plugs exhibited normal operating wear signatures in accordance with the Champion aviation check-a-plug comparison chart. The fuel pump remained attached to the engine and exhibited thermal and impact damage. The fuel mixture control was in the "full rich" position. The pump was removed from the engine and the drive coupling was intact. The cylinders were inspected using a lighted borescope. The cylinder bores were free of scoring within the bore ring travel area. A complete teardown examination of the engine revealed there were no mechanical deficiencies that would have precluded the engine from operating normally at the time of the accident.

MEDICAL AND PATHOLOGICAL INFORMATION

The Oklahoma Office of the Chief Medical Examiner, Oklahoma City, Oklahoma conducted autopsies on both pilots on February 3, 2008. The cause of death was determined to be multiple blunt force injuries.

The FAA Toxicology Accident Research Library, Oklahoma City, Oklahoma, conducted toxicological Testing. Both pilots tested negative for carbon monoxide, cyanide, ethanol, and drugs.

TESTS AND RESEARCH

The airplane was equipped with an Avidyne EXP5000 primary flight display (PFD) and an Avidyne EX5000 multi-function flight display (MFD). The Avidyne displays are the main two elements of the airplane’s Electronic Integrated Flight Deck. The displays present navigation and flight data to the pilot on liquid-crystal computer screens, replacing the individual gauges and flight instruments found in earlier generation general aviation airplane cockpits. The PFD, which records performance parameters, samples and stores several data streams in a sequential fashion; when the recording limit of the PFD is reached, the oldest record is dropped and a new record is added. The MFD, which records engine RPM and manifold pressure, generates new data files for each power on cycle. New MFD data are sampled every 6 seconds, and recorded to memory once every minute. If an interruption of electrical power occurs during the minute between MFD memory-write cycles, data sampled during that portion of a minute are not recorded.

In this case, the MFD data ended at 17:12:29.7, but the PFD data recorded until 17:13:13.8. Consequently, the last 44 seconds of MFD data were lost, most likely due to the 1-minute data-writing interval.

A Safety Board National Resource Specialist for Aircraft Performance performed an Aircraft Performance study. This study described the results of using weight and balance information, PFD and MFD data, POH information, and flight-test data to define the position of the airplane relative to the runway 19 threshold, and to compare the performance of the airplane during the last 44 seconds of the flight with the nominal performance of the SR22.

The results of the performance study showed that the airplane was within the allowable weight and balance envelope at the time of the accident. The lift and drag coefficients were consistent with the expected flaps-up performance of the SR22 at idle power, and a gross weight of 3,150 pounds. The data revealed:

At 17:12:30, as the airplane descended through 1,700 feet msl (735 feet agl) at a reduced power setting (16.4 inches of Mercury, manifold pressure 2,000 RPM), on a track consistent with a right downwind for runway 01 at Lindsay Airport.

While there was no engine data available after 17:12:30, the computed coefficient of drag after this time matched the data obtained from flight tests of the SR22 with the flaps retracted and the engine at idle power. Consequently, it was likely that the power remained at idle speed for the remainder of the flight.

At 17:12:47, while descending through 1,520 feet (555 feet agl), the airplane entered a right bank, and reached a 47-degree bank angle at 17:12:56. This right turn was consistent with making a turn onto left base for runway 19. During this time, the airplane's angle of attack increased from about 6.5 degrees at 17:12:47 to 10 degrees at 17:12:56.

At 17:13:05, when the airplane was at an altitude of 1,200 feet (235 feet agl), the airplane rolled through a wings-level attitude at a roll rate of 25 degrees per second into a steep left bank, in a turn towards runway 19. During this maneuver, the airplane's descent ceased but the angle of attack increased from 10 degrees to 15 degrees.

At 17:13:08, at a left bank angle of 53°, the airplane over flew the extended centerline of runway 19 at an altitude of 1,188 feet msl (223 feet agl). A second later, the left bank angle reached 60 degrees and the angle of attack exceeded 17 degrees. This angle of attack was consistent with flight test data for a flaps-retracted, wings level stall.

According to the Aircraft Performance Study, "Analysis of the angle of attack distribution along the wing during the final seconds of the flight indicated that at about 17:13:09, the angle of attack at every point along the left wing, from the centerline to the wingtip, exceeded the wings-level stall angle of attack of 17 degrees, while the angle of attack along the right wing was below 17° everywhere. This angle of attack distribution may have caused the left wing to stall before the right wing, decreasing the lift and increasing the drag on the left wing. This in turn would have generated additional yawing and rolling moments to the left, which may have produced the increase in left rolling and yawing rates observed at 17:13:09, and the increase in bank angle from -60° to -80°.

Between 17:13:09 and 17:13:11, the roll and yaw accelerations and rates reversed suddenly, and the airplane rolled and yawed violently to the right. The rapid roll rate to the right also reversed the distribution along the span, so that the right wing became deeply stalled, while the outboard portions of the left wing dropped below 17° angle of attack. This new angle of attack distribution generated an additional right rolling moment, accelerating the roll to the right. The reversal in yaw acceleration at 17:13:10 preceded the reversal in roll acceleration slightly. Hence, the initiating event of the roll and yaw reversals seems to have been the sudden yaw acceleration to the right. Such acceleration might have been provided by an abrupt and large right rudder input. In fact, the sudden application of a large rudder input during an accelerated stall is a well-known method of entering a snap roll. The circumstances of the sudden roll and yaw reversal to the right during the final moments of the accident flight appear similar to those of a snap-roll maneuver. It is possible that the pilots, faced with the increased roll rate to the left due to the stall of the left wing, input right rudder along with right aileron in an attempt to recover to wings-level, resulting in the snap-roll to the right. Once inverted, there was insufficient altitude to recover before impact with the ground."

ADDITIONAL INFORMATION

The airplane wreckage was released to a representative of the owner's insurance company.

NTSB Probable Cause

The flight instructor's failure to maintain control of the airplane, which resulted in an inadvertent stall while maneuvering.