NTSB Factual Report

HISTORY OF FLIGHT

On March 3, 2013, about 1558 mountain standard time, a Cessna 172M, N5129R, impacted trees and snow covered mountainous terrain 11 nautical miles east northeast of Saratoga, Wyoming. The commercial pilot was fatally injured and the airplane sustained substantial damage. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91, as a cross-country flight. Visual meteorological conditions prevailed and a visual flight rules flight plan was filed. The flight originated from Bryce Canyon Airport (KBCE), Bryce Canyon, Utah, at 1225 with a destination of Laramie Regional Airport (KLAR), Laramie, Wyoming.

A witness, east of Saratoga, saw an airplane fly overhead in an easterly direction near the time of the accident. She stated that the airplane wasn't visible until directly overhead through an opening in the low and broken clouds. She stated that it was about 500 feet above the ground. The sound of the engine was heard continuing east, and subsequently headed north as if it were to fly along the foothills of Pennock Mountain. She stated the foothills and Pennock Mountain were not visible because of the low clouds.

According to the Federal Aviation Administration (FAA), the estimated time of arrival for the flight to KLAR was 1620, and it was considered overdue at 1650. When the VFR flight plan was not closed, an INREQ (information request) was issued by the Prescott Flight Service Station (FSS), followed thereafter by an ALNOT (alert notice) at 1719. Meanwhile, the Air Force Rescue Coordination Center (AFRCC) received an emergency locator transmitter (ELT) signal at 1558 and contacted the Casper FSS and the Carbon County Sheriff's Office in Rawlins, Wyoming. The local search and rescue were contacted about 1700. Search efforts were halted several times due to variable ELT position estimates and deteriorating weather conditions. The airplane was located about 1249 on March 5, by an Air Force helicopter crew who used the reported ELT position to visually locate the airplane.

PERSONNEL INFORMATION

A review of FAA airman records revealed that the 63-year-old-pilot held certificates for commercial and certified flight instructor with ratings for airplane single-engine land, airplane multiengine land, and instrument airplane. He also held an airframe and powerplant mechanics certificate. His second-class medical certificate was issued June, 21, 2012, with the limitation that he must wear corrective lenses.

An examination of the pilot's logbook indicated a total flight time in all airplanes of 3,415 hours. He logged 23 hours in the last 90 days.

AIRCRAFT INFORMATION

The Cessna 172M is a four-seat, single-engine, high-wing airplane. A review of the airplane's logbooks revealed the airplane had a total airframe time of 13,190 hours at the most recent 100-hour inspection on January 5, 2013. The Hobbs hour meter read 4,880.2 hours at the accident site. The engine was a Textron Lycoming O-320-E2D, serial number L-44988-27A. Total time recorded on the engine at the most recent 100-hour inspection was 11,977 hours, and time since major overhaul was 1,328 hours.

METEOROLOGICAL CONDITIONS

An automated surface weather observation at Rawlins Municipal Airport/Harvey Field (KRWL), Rawlins, Wyoming (elevation 6,817 feet, 38 miles northwest of the accident site) was issued 5 minutes before the accident. It indicated wind from 250 degrees at 21 knots gusting to 28 knots, 10 miles or greater visibility, with a broken ceiling at 2,000 and 2,500 feet above ground level (agl), with an overcast ceiling at 8,000 feet agl, temperature at 3 degrees Celsius, dew point 0 degrees Celsius, and an altimeter setting at 29.79 inches of mercury.

According to the weather brief that the pilot received during his preflight briefing, a low pressure system was depicted over the northeast section of Wyoming with a trough extending southeast. Station models over southern Wyoming depicted west-southwesterly winds, light rain and/or drizzle, and overcast clouds. No significant weather echoes were found over the region. At KLAR, winds were 17 to 19 knots gusting between 25 and 29 knots. Area Forecast charts revealed broken clouds, and westerly winds at 20 knots gusting to 30 knots over the southeastern region of Wyoming. Inflight weather advisories (AIRMET) were issued for mountain obscuration conditions and moderate turbulence for the area.

The McIDAS satellite imagery showed low clouds over the area of the accident site with indications of mountain wave activity and other orographic clouds.

AIRPORT INFORMATION

According to data obtained by a personal GPS, the flight path vectored directly over Shively Field Airport (KSAA), near Saratoga, Wyoming at an altitude of 3,000 feet agl. The FAA Digital Airport/Facility Directory indicated that KSAA airport had an Automated Weather Observation System (ASOS), which broadcasts on frequency 118.175. During the postaccident examination, the ASOS frequency of 118.175 was observed in the airplane's communications radio when the unit was turned on.

WRECKAGE AND IMPACT INFORMATION

Examination of the accident site by the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) revealed the airplane impacted snow covered terrain and several medium sized trees that were about 5-6 inches in diameter. The airplane came to rest alongside tall trees on the east side of Pennock Mountain at an elevation of 8,570 feet, and oriented on a heading of 214 degrees magnetic. The first identified point of contact (FIPC) was a deep trough in the snow about 3 feet wide, 6 feet in length, and about 2 feet in depth. Three impacted trees were broken about 6 feet up from their bases, and were located within the 20 feet between the FIPC and the airplane's left wing tip. A section of tree, about 12 feet in length and about 5 inches in width, was severed cleanly in a diagonal linear pattern on one end, and was found on the right side of the fuselage, straddling the right horizontal stabilizer and vertical stabilizer. The diagonal linear pattern was about 18 inches in length. During the recovery process, another section of tree was found with a diagonal linear pattern similar in size.

The airplane remained intact with only the separation of the left wing tip fairing. The left and right wings had leading edge impact damage, and the upper surface of the left wing had buckling near the root area. The right wing side strut was bent upwards at its mid-section. The fuselage was crushed rearward at the firewall, and buckling was observed aft of the baggage door and forward of the right horizontal stabilizer. The right horizontal stabilizer leading edge, vertical stabilizer, and rudder had impact damage. The engine and cowling assembly was pushed aft from their original position. The one visible propeller blade was bent aft near the tip. The windshield separated, and was found in several sections around the forward side of the airplane. The top side of the left door made contact with the lower side of the left wing, and was difficult to open. The pilot's control yoke separated from its control rod, and was found hanging on the exterior of the airplane from the communications cord. The left side of the instrument panel and center console was damaged and distorted. The emergency locator transmitter was found separated from its mount, and remained attached to the antenna connection.

Fuel was removed from the left wing tank, and tested negative for water contamination. Due to the position of the right wing, fuel could not be removed from the right wing tank.

According to first responders, the pilot was found beneath the airplane's wing near the left entry door. The left entry door was ajar and on scene evidence suggests that the pilot egressed out the broken windshield to the left side of the airplane. The pilot was dressed in multiple layers including long underwear. A sleeping bag was found underneath the pilot's torso. Survival gear was found in the airplane and on the pilot's person. Additional food and water and another sleeping bag were found inside the airplane.

The airplane was recovered to a secure location where a postaccident examination took place. The airframe, flight control system components, and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted by the McKee Medical Center in Loveland, Colorado as a request from the Carbon County, Wyoming, Coroner's Office. According to the autopsy report, the cause of death is considered to be hypothermia because of the extreme winter conditions at the time of the accident, and the fact that the injuries the pilot sustained during the accident were not in and of themselves severe enough to be considered fatal.

Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology testing revealed only famotidine (an over the counter treatment for heartburn symptoms marketed under the trade name Pepcid) in urine, but not in blood. Analysis of the specimens contained no findings for carbon monoxide or volatiles.

SURVIVAL ASPECTS

Pilot Seat

The pilot's seat was found at its full forward position with damage to three of its support feet. The seat rollers were secured on the tracks. No secondary seat stops were observed on the pilot's seat tracks.

Pilot Restraint

According to the airplane's documentation, the seat belt and dual shoulder harness assemblies were installed in the airplane on February 9, 2003.

The pilot restraint was manufactured by Aero Fabricators (model number H-702, manufacturing date illegible), and the shoulder harness label stated the restraint system was a FAA-PMA part with a "rated strength of assembly [of] 1,500 pounds."

The three-point seat belt harness assembly located at the pilot's seat was attached to the airframe, and the lap belt was undamaged. The shoulder harness revealed separated webbing at the stitched attachment junction at the "Y" that joined the shoulder strap webbing located behind the occupants head to the webbing leading to the fuselage connection. No anomalies were noted with the installation of the three-point seat belt harness assembly. The seat belt assemblies were removed from both forward seats for further examination.

SHOULDER HARNESS RESTRAIN SYSTEM TESTING

Webbing Breaking Strength Testing

NTSB Survival Factors Specialists examined the shoulder harness restraint from the accident airplane, and performed testing at an independent research laboratory on exemplar shoulder harness restraint systems ordered from Aero Fabricators. In accordance with the Society of Automotive Engineers Aerospace Standard (SAE AS) 8043B, the breaking strength of the webbing was measured approximately 20.9 kilonewtons (kN) (4,700 pounds), which met the breaking strength requirement for upper torso of 17.8 kN (4,000 pounds), but did not meet the breaking strength requirement for the pelvic of 22.2 kN (5,000 pounds).

Technical Standard Order (TSO) C22f, dated January 01, 1990, was effective at the time Aero Fabricators applied for the seat belt STC. TSO C22f stated "new models of safety belts that are to be identified with applicable TSO markings and that are manufactured after May 1, 1972, must meet the standards set forth in National Aerospace Standard (NAS) Specification 802 revised May 15, 1950. NAS 802 stated the rated minimum breaking strength of the webbing to be used in belts shall be at least 50 percent greater than the rated strength of the complete belt assembly, i.e. 1,500 pounds. Therefore, the pelvic breaking strength requirement at the time of Aero Fabricators STC application was 2,250 pounds (10kN).

Although, the breaking strength of the webbing did not meet the TSO pelvic requirements currently effective as detailed in AS 8043B, the webbing breaking strength met TSO standards in effect at the time of STC approval.

Thread Testing

The same thread type that was used in the manufacturing of the Aero Fabricators shoulder harness restraint system was used to conduct thread tensile strength and elongation testing. The thread met the minimum breaking strength.

For further details, see the Survival Factors Factual Report in the public docket for this accident.

TESTS AND RESEARCH

The ELT was tested by the manufacture, and no anomalies were noted. No evidence of preimpact mechanical failure was noted during the examination. For further information, see the ELT Examination Summary contained within the public docket for this accident.

A personal GPS unit was recovered from the airplane, and revealed a flight track for about 3 hours and 25 minutes, departing from KBCE and ending near the accident site location. The track began with a northeasterly heading at an altitude between 12,000 to 12,500 feet mean sea level (msl), with a ground speed about 120 knots, until it reached the Meeker, Colorado, area where the track turned south. The track continued south for about 3 minutes before it turned on a north-northeasterly track, descending to about 8,500 feet msl until reaching the Dixon, Wyoming, area. The track turned east and then shortly northeast crossing over the Shively Field Airport (SAA) in Saratoga, Wyoming, at 3,000 feet above ground level (agl). The track continued on an easterly course making a short 360 degree turn before crossing over a private airstrip and crossing near the summit of Kennaday Peak, a 10,810 foot peak. The track turned northeast, and made two consecutive 360 degree turns followed by an s-type turn. The track continued another 3 miles east then headed in the direction of SAA, about 12 miles to the west. For the last 6 minutes, the track continued westward between about 10,000 and 9,000 feet msl, to the last recorded position at 8,940 feet msl, about 900 feet agl, with a ground speed of 58 knots. For further information, see the GPS Factual Report contained within the public docket for this accident.

ADDITIONAL INFORMATION

Other Accident Involving Failed Aero Fabricators Shoulder Harness

On September 1, 2012, approximately 0830 eastern daylight time, an Aeronca 7AC single-engine airplane, N82383, sustained substantial damage when it impacted terrain following a loss of control during initial takeoff climb from the Brighton Airport (45G), Brighton, Michigan. The private pilot sustained serious injuries, and the passenger sustained fatal injuries.

During the on-scene wreckage documentation, the shoulder harness located at the pilot's position was separated at the stitched attachment junction at the "Y" that separated the two shoulder straps located behind the occupants head. The restraint located at the forward passenger seat position was undamaged.

NTSB Probable Cause

The pilot’s decision to attempt flight into approaching adverse weather, which led to his low-level flight, encounter with mountain obscuration and moderate turbulence, and his subsequent loss of airplane control. Contributing to the severity of the pilot’s injuries was the failure of the seat restraint assembly.