NTSB Factual Report

HISTORY OF FLIGHT

On November 19, 2013, at 1810 mountain standard time, a Cessna T210M airplane, N6832B, impacted terrain near Cedaredge, Colorado. The pilot, the sole occupant, was fatally injured and the airplane was destroyed. The airplane was registered to and operated by Montana National Incorporated under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Night conditions existed at the time of the accident, and no flight plan was filed prior to departure. The flight departed from the Zamperini Field Airport (TOA), Torrance, California at 1448 and was destined for Aspen-Pitkin County Airport (ASE), Aspen, Colorado.

According to voice recordings provided by the Federal Aviation Administration (FAA), the airplane was inbound to KASE at 13,500 feet mean sea level (MSL), with the pilot receiving visual flight rules (VFR) flight following services from Denver Air Route Traffic Control Center (ARTCC). The pilot requested an instrument flight rules (IFR) clearance about 55 miles southwest of ASE. The controller issued an IFR clearance to ASE at 15,000 feet MSL and requested that the pilot transmit flight plan information.

While the pilot was transmitting the requested flight plan information, the controller observed the airplane make a significant left turn (about 180 degrees) away from the assigned clearance. When the controller inquired as to the airplane's heading, the pilot stated that his autopilot had disconnected. The controller subsequently issued the pilot a heading back towards ASE, which the pilot accepted. The airplane continued to turn left and made a rapid descent. Both radar and radio contact were subsequently lost.

PERSONNEL INFORMATION

The pilot, age 57, held a private pilot certificate with airplane single-engine land and instrument ratings. On March 1, 2013, the pilot was issued a Class 3 medical certificate, which required corrective lenses be available for near vision. At the time of the medical examination, the pilot reported having 1,560 hours of total flight experience, with 50 hours in the last six months. The pilot reported 950 hours in the make and model of the accident airplane on his policy renewal for aircraft insurance, dated May 16, 2013. Recent pilot logbooks were not available for the investigation.

The pilot received his instrument rating on August 8, 2011. The flight instructor who recommended the pilot for his instrument rating stated the pilot was very thoughtful and analytical, with strong flying skills. The flight instructor stated all their training flights occurred in the Southern California area. Actual instrument meteorological conditions encountered during the training were typically stratus clouds. About a month prior to the accident, the pilot had flown instrument approaches into TOA with a friend as the safety pilot.

AIRCRAFT INFORMATION

The accident airplane, a 1978 Cessna T210M, was registered to Montana National Inc. A standard airworthiness certificate was issued for the airplane on August 14, 1978. The airplane was equipped with a Continental TSIO-520R (serial 512927) engine. The last annual inspection was performed on the airplane on May 15, 2013, with a total of 3,549.5 hours.

The airplane was equipped with a Garmin VHF GNS-430 integrated global positioning system (GPS) navigation/communications transceiver and a Cessna 400B Nav-O-Matic autopilot system. On January 18, 2008, a DAC International GDC 31 Roll Steering Converter was installed, which interfaced with the existing Cessna 400B autopilot system. On January 24, 2012, an overhauled attitude indicator and horizontal situation indicator (HSI) were installed.

The airplane was equipped with a dual pump vacuum system. Both left and right vacuum pumps were replaced on August 3, 2012. During the annual inspection on May 15, 2013, air and vacuum filters were replaced. No other maintenance entries for the vacuum or avionics system were made following this annual inspection.

WEATHER INFORMATION

The weather observation station at Blake Field Airport (AJZ), Delta, Colorado, located about 14 miles southwest of the accident site, reported the following conditions at 1815: wind 120 degrees at 4 knots, visibility 10 miles, broken clouds at 5,000 feet above ground level (AGL), overcast clouds at 6,500 feet AGL, temperature 7 degrees Celsius, dew point negative 2 degrees Celsius, altimeter setting 29.95. AJZ field elevation is 5,193 feet MSL. An Airmen's Meteorological Information (AIRMET) for moderate turbulence and icing was active in the area of the accident.

A regional Next-Generation Radar (NEXRAD) mosaic obtained from the National Climatic Data Center for 1815 identified light values of reflectivity 2, consistent with snow showers, in the immediate vicinity of the accident location. An NTSB weather study is located in the public docket.

COMMUNICATIONS

The pilot received a preflight weather briefing, via telephone, from the Prescott Flight Service Station (FSS) at 1230. The FSS briefer pointed out an AIRMET for moderate turbulence and icing and stated that the icing AIRMET was valid from 8,000 feet msl to flight level (FL) 200 within the last 120 miles of the pilot's planned route of flight.

While flying from TOA to ASE, the pilot obtained four weather updates, via radio, from Prescott Flight Watch, at 1529, 1652, 1721, and 1802. During each of these updates, the pilot was informed of the icing AIRMET valid for the area west of ASE. During the 1802 weather update, the pilot stated that he had started to encounter snow from above, but that it was clear to the ground.

After departing from TOA, the pilot received VFR flight following service from FAA air traffic control (ATC) facilities as he flew towards ASE. The pilot was in communication with Denver ARTCC (DEN) at the time of the accident. The following summary is between DEN and the pilot (N6832B):

1801: N6832B asked for permission to go off frequency to obtain the weather at Aspen.

1805: N6832B reported back on frequency and was given a new Grand Junction altimeter setting.

1806: N6832B requested an IFR clearance to Aspen. After a short discussion about flight plans, requested routes and altitudes, N6832B was given an IFR clearance.

1807: The controller asked N6832B to read the IFR flight plan information on the frequency. The pilot complied by stating the requested information.

1808: The controller asked N6832B if he was making a 360 degree turn. The pilot said the autopilot had disconnected.

1809: The controller assigned N6832B a heading for Red Table VOR.

1810: After noticing the airplane descend, the controller asked N6832B to verify altitude, but received no response. The controller made two more calls for the aircraft.

Communications between the pilot and ATC, FSS, and Flight Watch during the accident flight are included in the public docket.

TESTS AND RESEARCH

A NTSB radar performance study, located in the public docket, was conducted to describe the accident airplane ground track, altitude, and speed. From 1800:00 until 18:06:35, radar indicated that the accident airplane was flying straight and level at 13,400 feet msl. Shortly after, Denver ATRCC provided an IFR clearance, which included instructions to climb to 15,000 feet msl.

The airplane reached a maximum altitude of 14,300 feet msl during a climbing turn to the left, during which the airspeed decayed to about 95 knots. As the left turn continued, a rapid descent of over 20,000 feet per minute occurred, during which the airplane reached a maximum airspeed of about 250 knots. The airplane completed a 360 degree left turn and impacted terrain about 20 seconds later.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted into hilly, vegetated terrain and came to rest relatively upright and leaning toward the left side of the fuselage on a rock covered hill. The cabin and instrument panel were consumed by a post-impact fire.

Several components of the airplane were found separated from the main wreckage. The largest of these components, a 15 foot outboard section of the left wing, was located about 1,450 feet from the main wreckage on a 311 degree heading. A 14 inch section of the left aileron outboard end, more than four feet of the left flap outboard end, and fragments of the left horizontal stabilizer and elevator also separated from the airplane. A wreckage debris diagram is located in the public docket.

The fractured left spar and left wing upper wing skin were bent aft and upward, consistent with the wing separating in a positive load. The leading edge of the left horizontal stabilizer and elevator exhibited impact damage consistent with being struck by the separated left wing. All separations of the airframe and flight control system appeared characteristic of overload.

Examination of the aileron flight control system revealed signatures consistent with aileron flutter. The left aileron/flap interconnect push-pull tube had torn through the spar web and impacted the left aileron stop bolt bracket. The left aileron stop bolt bracket was bent and separated from the spar. The left and right aileron stop bolt heads and bell crank stops exhibited hammered flat spots and metal smearing.

The attitude indicator gyro was examined and showed indications of rotational scoring. The left and right vacuum pumps were disassembled and examined. Both pump housings exhibited impact damage and the respective plastic drive couplings could not be rotated by hand due to thermal damage. The respective carbon vanes were intact for each pump, with the rotor for each pump fractured into several pieces. The vacuum and avionics system were not capable of being tested, due to significant fire damage.

The engine sustained thermal damage to the ignition harness and severe impact damage to cylinder numbers 2, 4, and 6. Cylinders 1, 3, and 5 remained attached and intact with some thermal damage. The left and right magnetos were thermally damaged and broken from their mountings. Spark could not be determined from either magneto. The spark plugs exhibited normal color and heat signature when compared to a Champion "Check A Plug" chart. The fuel pump remained in place and intact, with the drive coupling intact. The fuel manifold remained attached to its mount, with the rubber diaphragm thermally damaged. All fuel lines and fuel injectors remained attached for all cylinders. The fuel screen was removed and found clear of debris.

Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

On November 20, 2013, an autopsy was performed on the pilot by the Delta County Coroner. The cause of death was blunt force injuries. The FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma performed toxicology tests on the pilot. No tested for drugs were detected.

ADDITIONAL INFORMATION

The unpressurized airplane had been level at 13,500 msl for about 3 hours when the accident occurred. Six oxygen cylinders were onboard, but the investigation was not able to determine if the pilot was utilizing them, due to post accident fire.

According to his wife, the pilot frequently flew with a pulse/blood oxygen sensor. By monitoring his blood oxygen percentage, the pilot felt confident in his ability to fly for extended periods at high altitude without using supplemental oxygen. Throughout the flight, the pilot's communications to ATC and Flight Watch were coherent and rational.

NTSB Probable Cause

The pilot's spatial disorientation while operating in dark night conditions in snow showers and his subsequent failure to maintain airplane control, which resulted in overstress of the airplane and an in-flight breakup. Contributing to the loss of control was the pilot's diverted attention while coordinating for an instrument flight rules clearance.