N2025D

Destroyed
Fatal

BEECH C35S/N: D-3376

Accident Details

Date
Thursday, January 14, 2016
NTSB Number
CEN16FA086
Location
Meeker, CO
Event ID
20160115X22543
Coordinates
40.052223, -108.278610
Aircraft Damage
Destroyed
Highest Injury
Fatal
Fatalities
1
Serious Injuries
0
Minor Injuries
0
Uninjured
0
Total Aboard
1

Probable Cause and Findings

The non-instrument-rated pilot's decision to fly the airplane in instrument meteorological conditions at high altitude for greater than 30 minutes without the use of supplemental oxygen which resulted in hypoxia, and a subsequent loss of control. Contributing to the accident was the pilot's use of multiple impairing medications.

Aircraft Information

Registration
N2025D
Make
BEECH
Serial Number
D-3376
Engine Type
Reciprocating
Year Built
1952
Model / ICAO
C35BE35
Aircraft Type
Fixed Wing Single Engine
No. of Engines
1

Registered Owner (Historical)

Name
HILER WILLIAM R
Address
PO BOX 332
Status
Deregistered
City
TABERNASH
State / Zip Code
CO 80478-0332
Country
United States

Analysis

HISTORY OF FLIGHT

On January 14, 2016 about 1745 mountain standard time (MST), a Beech C-35 single-engine airplane, N2025D, was destroyed when it impacted terrain near Meeker, Colorado. The private pilot was fatally injured. The airplane was privately owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Instrument meteorological conditions prevailed, and no flight plan was filed for the personal flight, which departed Provo Municipal Airport (PVU), Provo, Utah, about 1620, with an intended destination of Granby-Grand County Airport (GNB), Granby, Colorado.

Radar data indicated that, after departure, the airplane circled and climbed to an altitude about 12,000 ft mean sea level (msl) in the general area of PVU before turning east toward mountainous terrain. [Note: All radar and/or air traffic control data is reference in ft msl in this report.] The airplane continued to climb as it traveled east, reaching about 14,500 ft about 1641. The airplane maintained between about 14,000 ft and 14,500 ft until about 1653, when it descended to just below 13,000 ft. The pilot contacted air traffic control at 1704, traveling east-southeast, and was issued the current altimeter setting. The airplane continued in the same direction after initial check-in and began a climb again, the airplane had climbed above 18,000 ft by about 1736. At 1736, the controller confirmed the airplane's altitude, advised the pilot he would require an instrument flight rules (IFR) clearance to fly above 18,000 ft, and asked the pilot if he wanted to file IFR. The pilot responded, "that would be great, I just want to get over (unintelligible) so I can get back down." The controller then asked if the airplane was IFR -equipped and -capable, to which the pilot responded that he was IFR-equipped. The controller subsequently cleared the flight direct to GNB and issued a block altitude between 17,000 ft and 19,000 ft.

Just after the pilot received the block altitude, the accident airplane stopped climbing about 18,400 ft; the controller subsequently asked the pilot if he could maintain 19,000 ft. The pilot responded that he was in the clouds, and the controller again asked if he could maintain 19,000 ft; the pilot responded, "we're getting there." The controller then instructed the pilot to maintain 19,000 ft.

Radar data indicated that, after reaching about 18,700 ft, the airplane abruptly descended to about 17,400 ft, turned to the north, and climbed back up to about 18,500 ft. The controller advised the pilot he observed him turning north asked the pilot if he was okay, to which the pilot responded, "a little bit." Radar data indicated that the accident airplane then turned to the west, descending more rapidly as the airplane entered a right spiral. At the onset of this change in direction and descent, the controller advised the pilot that he observed him in a turn and descending and asked if he was in control, to which the pilot responded, "uh yes."

The controller then advised the accident pilot not to descend lower than 11,000 ft and cleared him to descend and maintain 11,000 ft. The controller advised "that's lowest I can get you." The pilot responded "alright (unintelligible) clear there." The controller advised he did not have any [weather] reports for that area and asked if he was planning to head back to the west, to which the pilot responded, "I'm at seventeen now".

The controller then advised the pilot he observed him doing some "S turns" and asked if he was proceeding to Grandby or heading back to the west. There was no response from the pilot. After two more attempts by the controller to reach the pilot, the pilot responded, "I hear you fine (unintelligible)." About 1744, the controller advised the accident pilot that Meeker airport was at his 3 o'clock and 17 miles, and there was an unintelligible response. There were no further recorded transmissions from the accident pilot.

The last radar target correlated with the accident aircraft was at 1743:33 and about 14,100 ft; however, OpsVue track data continued to record, showing the airplane in a continued descent until 1744:13 and about 10,300 ft before track data terminated. OpsVue is a commercially available web-based flight tracking program. The track is derived from a combination of several surveillance sources that are combined and a "mosaic" type of flight track is produced.

PERSONNEL INFORMATION

The pilot, age 62, held a private pilot certificate with a rating for airplane single-engine land. The pilot did not have an instrument rating. No pilot logbooks were available for review. On his most recent Federal Aviation Administration (FAA) third-class medical certificate application, dated November 6, 2015, the pilot reported about 600 total hours of flight experience, with 20 hours in the previous six months. The medical certificate was issued with a limitation that he: must have available glasses for near vision.

AIRCRAFT INFORMATION

Review of preaccident photographs of the airplane showed the airplane was equipped with a homebuilt oxygen system consisting of two oxygen tanks, two vinyl oxygen masks, and the associated vinyl oxygen supply tubing. The two oxygen tanks were attached to the fuselage wall behind the bulkhead on the left side of the airplane. The oxygen supply tubing attached to each tank and ran forward toward the cockpit area. The valves on the tanks were not able to be accessed to start or stop the flow of oxygen from the cockpit.

The airplane model has a service ceiling of 18,500 feet MSL.

METEOROLOGICAL INFORMATION

Although the pilot checked weather information prior to flight with Lockheed Martin Flight Service (LMFS), the data and weather information discussed was not able to be retrieved for this investigation. There was no indication that the pilot received any additional weather briefing information before the flight.

At the time and location of the accident, AIRMETs were active for IFR conditions, mountain obscuration, moderate icing below 12,000 ft, and moderate icing between the freezing level and 17,000 ft. The Area Forecast valid at the time of the accident predicted an overcast ceiling at 10,000 ft with layered clouds to 25,000 ft. Visibility of 3 miles, mist, and light snow were forecast through 1700 with visibility increasing to 5 miles with mist after 1700.

Meeker Coulter Field Airport (EEO), Meeker, Colorado, was located about 18 miles east of the accident site, at an elevation of 6,415 ft. The 1653 observation included calm wind, 9 miles visibility, light snow, an overcast ceiling at 3,900 ft agl, temperature -2°C, dew point of -8°C, and an altimeter setting of 29.89 inches of mercury. Remarks included: station with a precipitation discriminator, snow began at 1648, sea level pressure 1018.0 hPa, 1-hour precipitation trace, 6-hour precipitation trace, temperature -2.2°C, dew point -7.8°C, 6-hour maximum temperature of -0.6°C, 6-hour minimum temperature of -6.7°C, and 3-hour pressure increase of 1.0 hPa.

The 1753 observation included calm wind, 10 miles visibility, an overcast ceiling at 4,300 ft agl, temperature -2°C, dew point temperature -7°C, and an altimeter setting of 29.89 inches of mercury. Remarks included: station with a precipitation discriminator, snow ended at 1658, sea level pressure 1017.1 hPa, 1-hour precipitation trace, temperature -2.2°C, dew point temperature -6.7°C.

A North American Mesoscale (NAM) model sounding was created for the accident site for 1700. The sounding indicated a relatively moist vertical environment from 9,000 ft through 15,000 ft. This environment would have been conducive to cloud formation between 9,000 ft and 15,000 ft. The cloud tops likely extended higher, up to 19,000 ft according to satellite imagery and weather radar data. Icing (clear, rime, and mixed) was indicated between 9,000 ft and 14,000 ft. The 1700 MST NAM sounding was also close to saturation between -8°C and -15°C (between 9,000 and 14,000 ft) which is considered a temperature range supportive of the growth of super cooled liquid water droplets.

A more detailed description of the weather in the area of the accident site is available in the Meteorology - Group Chairman's Weather Study Report in the public docket.

WRECKAGE AND IMPACT INFORMATION

The airplane was located in tree- and sagebrush-covered, mountainous terrain about 19.5 miles west of Meeker, Colorado. The terrain elevation in the area varied from 6,200 to 6,400 ft msl. The main wreckage included the fuselage, left wing, engine, and propeller hub. The remaining wreckage was scattered over an area about 0.3 mile north-south by 0.4 mile east-west and was distributed in a manner consistent with an in-flight breakup. The wreckage was examined during recovery and later at a secure storage facility.

Airframe

Control continuity was established from the control yokes through the fuselage to the aft side of the center section rear spar. The right aileron cables fractured from the bell-crank in the right wing and the left aileron cables were cut during recovery. The ruddervator control and autopilot cables remained attached to the ruddervator differential mechanism in the tail and were cut at the forward end of the empennage during recovery. The ruddervator trim cables exhibited a splayed appearance consistent with tension overload. Continuity of the cables from the empennage to the rear spar could not be established because the cables were cut and removed during recovery.

The inboard portion of the right wing was deformed upward and there was diagonal wrinkling of the upper and lower wing skins. All 4 wing attach tension bolts were intact and installed through portions of the bathtub fittings. The fractures at the right wing separation point all exhibited a dull, grainy appearance consistent with overload. The left wing was located with the main wreckage and was partially attached to the fuselage.

The right stabilizer was ...

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN16FA086