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On April 10, 2001, about 1850 mountain standard time, a Cirrus SR20 single engine airplane, N116CD, collided with mountainous terrain and burned northwest of Sierra Vista, Arizona. The airplane was destroyed, and the noninstrument rated private pilot and two passengers received fatal injuries. The airplane was registered to, and operated by, the pilot/owner as a personal flight under the provisions of 14 CFR Part 91. The flight originated from the Tucson, Arizona, International Airport at 1830, with Belen, New Mexico (E80), as the intended destination. Instrument meteorological conditions prevailed at the accident site and no flight plan had been filed.
The pilot and two passengers were from Wisconsin, and were in Tucson visiting relatives. According to air traffic control records, the pilot radioed the Tucson Clearance Delivery requesting a visual flight rules (VFR) clearance, with a heading of 100 degrees at 3,800 feet to E80. After takeoff, the pilot was instructed to turn to a heading of 120 degrees and to expect an on course clearance from the next controller, and was then instructed to contact departure control. Departure control instructed the pilot to make a left turn to a heading of 030 degrees. The controller then verified the pilot's requested heading and cleared the flight to turn on course. At 1843, radar service was terminated and the pilot was instructed to squawk VFR (transponder code 1200), to which the pilot acknowledged.
Concerned family members reported the aircraft overdue when it failed to arrive as scheduled. Civil Air Patrol initiated a search and personnel located the accident site on April 14, 2001. The burned wreckage was located approximately 150 feet below the crest of a ridgeline in the Whetstone Mountains, at 5,200 feet mean sea level (msl). The accident site was approximately 52 nautical miles southeast of Tucson. Belen is located northeast of Tucson.
The noninstrument rated pilot held a private pilot certificate with an airplane single engine land rating. He was issued a third-class medical certificate on January 24, 2000, with a limitation to wear corrective lenses. According to his last medical application, the pilot reported having accumulated a total of 1,450 hours of flight time. Utilizing the aircraft maintenance records, Safety Board investigators estimated that the pilot accumulated approximately 116.6 hours of flight time in the accident airplane as of February 6.
According to Cirrus Design, the pilot received SR20 familiarization training between February 3 and February 6, 2000. The training course consisted of five ground training lessons and four flight training lessons. The flight training consisted of basic flight maneuvers, takeoffs and landings, stalls, global positioning system (GPS), emergency procedures, and instrument flying familiarization. The instrument portion covered procedures for recovery from visual flight rules (VFR) flight into instrument meteorological conditions (IMC).
The single engine, composite airplane was powered by a 200-horsepower Teledyne Continental IO-360-ES engine and a 3-blade, constant speed Hartzell propeller. The airplane was equipped with an airspeed indicator, attitude indicator, altimeter, turn coordinator, heading indicator, and vertical speed indicator. It was also equipped with two Garmin 430 radio/GPS/COMNAV/moving maps and an ARNAV ICDS-2000 Multi Function Display (MFD) with a 10-inch screen. The ARNAV unit displays navigational waypoints, course line, ground speed and other information, which is fed to the ARNAV screen from the No. 1 Garmin 430 radio. The ARNAV unit also has a separate database, which displays terrain elevations based on position. The Garmin 430 is approved for instrument flight rules (IFR) operation; however, the ARNAV MFD is for reference only, and is not certified for flight in instrument conditions.
The accident airplane was equipped with a ballistic recovery parachute system, manufactured by Ballistic Recovery Systems (BRS). According to Cirrus Design, the Cirrus Airframe Parachute System (CAPS) is a ballistic recovery device that will lower the entire airframe to the ground when all alternatives to land the aircraft have been exhausted. The CAPS consists of a parachute, a solid propellant rocket to deploy the parachute, a rocket activation handle, and a Kevlar harness imbedded within the fuselage structure. The pilot activates the system by pulling on a T-handle mounted on the cockpit ceiling. This action activates the firing pin mechanism, which in turn ignites the solid propellant rocket in the parachute canister.
The aircraft was manufactured and issued an airworthiness certificate in the beginning of 2000. The only and last annual inspection was conducted at the Cirrus Design factory service center between February 5 and February 16, 2001. At that time, the aircraft and engine had accumulated 116.6 hours total time. According to the annual inspection discrepancy list, the turn coordinator was found to be inoperative and was replaced. All applicable service bulletins were complied with at the time of the annual inspection. It is not known how many hours the aircraft had accumulated after the annual inspection up until the time of the accident.
One of the local sheriff's deputies, who is a pilot and lives approximately 2 miles from the base of the Whetstone Mountains, said the weather the day of the accident was "terrible" with icing, sleet, snow, rain, and wind, and he could not see the base of the mountains from his home.
A printed copy of weather information, dated April 10, 2001, was found scattered around the accident site. The printed sheets appeared to be incomplete, and included weather information from Arizona to Wisconsin. The information included winds aloft information, notices to airmen, current weather (METAR), terminal forecasts (TAF), and text weather radar data. It is uncertain whether more of the weather information was burned in the wreckage.
A section of the printed weather information found at the accident site concerned a terminal forecast for Albuquerque, New Mexico, (issued at 0535 on the 10th). This TAF indicated between 1800 and 2300 the wind would be from 270 degrees at 20 knots gusting to 30 knots; visibility would be greater than 6 miles; ceilings would be broken at 7,000 feet; and showers may be in the vicinity.
According to Flight Service Station archived information, the pilot obtained DUATS weather information at 0709 and 0926 on the morning of the accident.
The Safety Board conducted a meteorological study and the following are excerpts of the findings:
Surface analysis charts prepared by the National Weather Service (NWS) for 1700 and 2000, on April 10th, showed closely packed isobars over Arizona and New Mexico oriented in a northwesterly-southeasterly direction. The 850 and 700 millibar charts for 1700, showed station plots on both charts that generally indicated westerly winds over Arizona at 20-25 knots. The 700 millibar analysis chart showed narrow temperature-dew point spreads at Albuquerque, Tucson, and Flagstaff, which indicated a nearly saturated atmosphere at these locations.
The closest weather reporting facility was located at the Safford Regional Airport (SAD), which was 11 nautical miles south-southeast of the accident site. At 1850, the weather observation facility reported the wind from 290 degrees at 12 knots; visibility 10 statute miles; a few clouds at 6,000 feet agl, and scattered clouds at 8,000 feet agl; temperature 4 degrees Celsius; dew point 1-degree Celsius; and an altimeter setting 29.94 inches of mercury. The remarks section of the 1850 report indicated that the rain began at 1755 and ended at 1834.
At 1855, the weather observation facility at the Tucson International Airport (TUS), located approximately 34 nautical miles northeast of the accident site, reported the wind form 280 degrees at 10 knots gusting to 17 knots; visibility 10 statute miles; broken clouds at 7,500 feet agl; temperature 11 degrees Celsius; dew point -5 degrees Celsius; and an altimeter setting of 29.99 inches of mercury. The remarks section of that report indicated rain and snow showers were in the distant northeast-east moving east.
Review of the 1555, 1655, 1755, and 1855 weather observations for TUS and the Davis Monthan Air Force Base (DMA, which is located approximately 6 nautical miles northeast of TUS), revealed each observation had remarks that indicated snow showers were over the mountains, northeast through the southeast, and they were moving east.
The Pilot Reports (PIREPS) were reviewed and the following were selected from the Tucson area:
At 1704, over Tucson, the flight crew of a Boeing 727 at 2,700 feet, reported "low level wind shear +/-10 knots indicated airspeed during climb [from] runway 29R."
At 1710, at a location 12 nautical miles on a 090-magnetic bearing from Tucson, the flight crew of a MD80 reported light to moderate clear icing at 11,000 feet.
Review of weather radar data at 1846, 1851, and 1856, revealed that precipitation reflectivities in the accident area did increase during these observations; however, no significant weather radar returns were shown in the vicinity of the accident site.
Geostationary Operational Environmental Satellite-10 (GOES-10) visible and infrared data centered on southeastern Arizona area during the period between 1800 and 1900, were obtained and examined. The visible data did not provide any useful information after 1830 due to darkness. Satellite data indicated that a band of clouds stretched across the I-10 corridor east of Tucson from the Rincon Peak area north of I-10 to the vicinity of the Whetstone Mountains south of the highway.
The area forecast for Arizona, specifically south and east of TUS, reported a chance of broken clouds at 6,000 feet, broken clouds at 11,000 feet with tops at flight level 220, and scattered light rain showers. The forecast indicated the conditions would slowly improve from the west, becoming scattered clouds at 8,000 feet over the entire Arizona area around 2100.
AIRMET TANGO, for an area of moderate turbulence, was issued at 1525, the day of the accident, and was valid until 1900, that evening. The area included in AIRMET TANGO included the departure airport, the accident area, and the destination airport.
AIRMET SIERRA, for areas of mountain obscurement, was issued at 1422, the day of the accident, and was valid until 1900, that evening. The area included the departure airport and the accident site. AIRMET SIERRA also indicated that the mountain obscurement conditions would end to the west and south of a line extending from Phoenix to St. Johns, Arizona, between 1800 and 1900; however, the remaining area of that the AIRMET would have continued mountain obscurement in clouds and precipitation beyond 1900 through 0100, on April 11, 2001.
AIRMET ZULU, for occasional moderate rime/mixed icing in clouds and precipitation below 16,000 feet, was issued at 1245, and was valid until 1900, and included the departure airport and accident site area.
All three AIRMETS were updated at 1845 (approximately 5 minutes prior to the accident). The 1845 AIRMETS for turbulence, IFR conditions and mountain obscurement, and freezing levels were valid until 0100 on the 11th, and included an area surrounding the arrival portion of the route of flight, the flight's destination airport.
At 1622, on April 10, 2001, a TAF for Tucson was issued and was valid from 1700, on the 10th until 1700, on the 11th. According to that TAF, the forecast called for wind from 270 degrees at 14 knots gusting to 24 knots; visibility greater than 6 miles; and clouds broken 6,000 feet. The forecast also indicated temporary conditions between 1700 and 1900, that included light rain showers, small hail, and cumulonimbus clouds broken at 3,500 feet. There is no indication the pilot obtained this TAF prior to departing since the last recorded DUATS information was obtained at 0926.
Astronomical data on April 10, for the approximate accident location, at an elevation of 5,200 feet msl, were calculated using Safety Board software package. According to the calculations, sunset occurred at 1853, and the end of civil twilight followed at 1918. The moon was located approximately 33 degrees below the horizon.
WRECKAGE AND IMPACT INFORMATION
On April 16, 2001, the Safety Board investigator examined the wreckage at the accident site with the assistance of investigators from Cirrus Design and BRS. The wreckage distribution was localized within about a 50-foot radius of a single ground disturbance scar on the approximate 35-degree slope of the mountain.
The lowest items found on the mountain were the top and bottom skins of the horizontal stabilizer followed uphill by the vertical stabilizer, landing gear, and pieces of the cabin. The wing spar remained on the lower side of the burn area, and the left and right flaps were aft of the spar on their respective sides of the wreckage. The top side of the right wing came to rest inverted approximately 50 feet to the right and uphill of the main wreckage area. The fuselage and cabin area were consumed by fire. Most of the fuselage material burned, and none of the cockpit instruments, avionics, or autopilot readings or indications were available. Flight control continuity was not confirmed due to the extent of the damage; however, control cables remained attached to the ailerons.
The engine came to rest within the main wreckage and burn area; however, it was canted approximately 80 degrees to the right when compared to the wreckage distribution direction. The propeller was separated from the engine, with one of the propeller blades separated from the propeller hub. All three blades displayed leading edge gouging and chordwise scoring, and one blade had the tip torn off.
It was noted that the BRS was not deployed. Though the BRS rocket fuel was expended, there was no apparent impact damage noted on the door that covers the parachute and rocket launching system. The rocket motor strike plate on the door did not show any signs of rocket motor impact, and the door was found in the main wreckage area. The parachute remained packed in its container and remained attached to the Kevlar parachute harness. Approximately 8-10 feet of the suspension lines were laid out among the wreckage. The parachute was pulled away from the wreckage and the remaining length of the suspension lines extended easily with no binding noted.
On April 17, 2001, the aircraft wreckage was recovered and transported to Air Transport, Phoenix, Arizona, for further examination.
On April 18, 2001, the wreckage was laid out and it was noted that all four corners of the airplane were present at the accident site, and all flight controls were accounted for. The flap jackscrew was separated from the flap transmission, and the flap selector switch was not recovered. The fuel selector valve was found selected to the right fuel tank.
The engine crankshaft was fractured just aft of the propeller flange and exhibited 45-degree shear lips with blue tinting at the fracture surface. The fuel pump, propeller governor, induction system, oil sump, front right/lower crankcase, lower portion of the accessory case, oil cooler, magnetos, starter, and alternators were found separated from the engine. Internal examination of the engine revealed that all six connecting rods and pistons were intact. Lubrication was present throughout the interior of the crankcase and no discoloration was noted.
TESTS AND RESEARCH
Cirrus Design personnel examined an exemplar aircraft with the same ARNAV/Garmin 430 unit and database as the accident aircraft. The accident site location was entered into the system and it was noted that the ARNAV database displayed the terrain elevations correctly.
A toxicological test for volatiles and drugs was conducted on the pilot. The results were positive for 38 mg/dL of ethanol detected in the heart; 36 mg/dL acetaldehyde detected in the heart; 1 mg/dL 2-butanol detected in the heart; 1 mg/dL n-propanol detected in the heart; 37 mg/dL ethanol detected in the lung; 13 mg/dL acetaldehyde detected in the lung; and 2 mg/dL n-propanol detected in the lung. No drugs were detected in the muscle.
The aforementioned toxicology results may have resulted from post-mortem ethanol production due to the length of time between death and specimen collection; however, that could not be conclusively determined with the specimens that were available.