N799RSCommander Aircraft 114-B · 1998

On December 24, 2010, about 1600 mountain standard time (MST), the wreckage of a Commander 114B, N799RS, was located by Civil Air Patrol searchers in the Wind River mountain range, about 20 miles southwest of Lander, Wyoming. Based on recorded radar and GPS data, the accident likely occured about 1145 on December 22, 2010. The owner/pilot and two passengers were fatally injured. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91, and no flight plan was filed. In addition, no overdue, or missing, aircraft reports regarding the airplane were received.

The search for the airplane was prompted by reports of emergency locator transmitter (ELT) signals received by overflying aircraft. The first signal was reported to the Federal Aviation Administration (FAA) Air Route Traffic Control Center (ARTCC) in Salt Lake City, Utah, about 1653 MST on December 23, 2010. According to personnel from Salt Lake ARTCC (ZLC), no air traffic services were provided to the airplane. According to Lockheed Martin Flight Service (LMFS) personnel, a review of LMFS records from November 12, 2010, to December 23, 2010, indicated that no services had been provided for the accident pilot or airplane. An LMFS check with the two Direct User Access Terminal Services (DUATS) providers also indicated that no services had been provided for the accident pilot or airplane during that same period.

Information provided by the airport and a rental car company indicated that the pilot made hangar and rental car reservations several weeks before the accident. The pilot's intended final destination was Driggs-Reed Memorial Airport (DIJ), Driggs Idaho, with a planned arrival date of December 22, 2010.

Although not actively worked by FAA air traffic control (ATC), post-accident review of ground-based radar tracking facility data indicated that the airplane was captured and tracked via its transponder returns. The transponder beacon code was set to 1200 for the duration of the flight.

A handheld global positioning system (GPS) unit was recovered from the wreckage. Data extracted from the Garmin GPSMap 696 indicated that on December 21, 2010, the airplane departed from its base at Jasper County-Bell Airport (JAS), Jasper, Texas, and flew for 4 hours 31 minutes to Dalhart Municipal Airport (DHT), Dalhart, Texas. That same day it departed DHT and flew for 2 hours 12 minutes to Fort Collins-Loveland Municipal airport (FNL), Fort Collins/Loveland, Colorado. The last GPS data point for that leg was recorded at 1906, when the airplane was about 3 miles southeast of FNL. Records indicated that the airplane was fueled with 25 gallons at FNL.

About 0937 on December 22, the airplane departed FNL on the accident flight. The airplane climbed to about 12,500 feet above mean sea level (msl; all altitudes are msl unless noted otherwise) and tracked northwest on a direct track towards DIJ. About 45 minutes after takeoff, the airplane descended gradually to about 11,500 feet, leveled for about 10 minutes, and then descended to about 11,000 feet. It then climbed back to about 12,500 feet, where it remained for about 50 minutes. About 2 hours 5 minutes after takeoff, the airplane began a series of descents and climbs, reversed course twice, and then began a climbing right turn to the northeast. The final GPS data point was recorded about 1145, about 1/2 mile west of the impact location, with a GPS altitude of 11,599 feet. The GPS and ATC flight track data were essentially congruent.

The pilot and two passengers were recovered on December 25, 2010. Due to terrain elevation, topography, and seasonal conditions, the wreckage was recovered on July 27, 2011.

According to FAA records, the pilot held a private pilot certificate, issued in October 2005, with an airplane single-engine land rating. He did not hold an instrument rating. His most recent FAA third-class medical certificate was issued in June 2006. The pilot's July 2010 aircraft insurance application indicated that he had a total flight experience of 710 hours, which included 456 hours in the accident airplane make and model. The investigation was unable to locate any pilot logbooks or other personal records of his flight experience.

An operations staff member at JAS stated that it seemed to be common knowledge among airport personnel (staff, airplane owners, and other pilots) that although the pilot was not instrument rated, he frequently filed instrument flight plans, and operated in instrument meteorological conditions (IMC). The operations staff member had heard other pilots complain about the pilot's flying habits in the vicinity of JAS, and in particular when IMC existed at JAS. The investigation was unable to obtain additional details regarding those observations.

An autopsy conducted under the auspices of the Fremont County Wyoming Coroner's Office indicated that the pilot's death was a result of "multiple blunt force injuries." The forensic toxicology examination report stated that with the exception of caffeine, no carbon monoxide, cyanide, ethanol, or any other screened drugs were detected. The FAA Civil Aeromedical Institute toxicology examination reported that with the exception of acetaminophen, no carbon monoxide, cyanide, ethanol, or any other screened drugs were detected.

According to FAA and manufacturer information, the airplane was manufactured in 1998 as serial number 14658, and was first registered to the pilot in August 2007. It was equipped with a normally-aspirated Lycoming IO-540 series engine. The airplane was equipped with two fuel tanks that had a total capacity of 70 gallons, of which 68 were useable. Maximum takeoff weight was 3,250 pounds. Climb and cruise performance data was published for altitudes up to and including 14,000 feet pressure altitude. The airplane was not approved for flight into known icing.

Examination of the airplane maintenance records revealed that the engine was removed from the airplane in June 2008 in order to comply with an FAA airworthiness directive (AD) regarding the crankshaft. Compliance with the AD and Lycoming Service Bulletin SB569A was completed on July 22, 2008, when the engine was reinstalled in the airplane. The records indicated that the airplane and engine had accumulated a total time in service (TT) of 651.3 hours at the time the engine was removed for compliance with the AD.

The most recent altimeter/encoder/static system check was completed in March 2007, when the airplane had a TT of 487.7 hours. The FAA mandatory inspection interval for those systems is 2 years. The most recent annual inspection was completed in June 2010, when the airplane had a TT of 963.3 hours. The most recent maintenance record entry was for an oil change dated November 5, 2010, when the airplane had a TT of 1,065.9 hours.

A review of the maintenance records did not reveal any entries that warranted additional investigation.

AIRMETs and SIGMETs

Airmen’s Meteorological Information (AIRMETs) are FAA issued advisories that contain and communicate information about current or forecast weather phenomena that may affect aircraft safety. AIRMETs are issued routinely every 6 hours, and are amended as necessary.

Multiple AIRMETs for IFR, mountain obscuration and icing conditions were issued and current for the accident flight area, below FL180 (approximately 18,000 feet). Those advisories included:

- An AIRMET ZULU advised of moderate icing between the freezing level and FL240.

- An AIRMET SIERRA for IFR conditions advised of ceilings below 1,000 feet agl, visibility below 3 statute miles, precipitation and mist.

- An AIRMET SIERRA advised of mountains obscured by clouds, precipitation and mist.

- An AIRMET TANGO advised of moderate turbulence below FL180.

Significant Meteorological Information (SIGMETs) are weather advisories that contain information pertaining to meteorological phenomena that affect the safety of all aircraft. SIGMETs are issued on an as-required basis. No SIGMETS were current for the accident flight area.

Area Forecast

Area Forecast information valid for the time and location of the accident flight forecast broken ceilings between 7,000 and 10,000 feet msl, with cloud tops to Flight Level (FL) 260 (approximately 26,000 feet), visibility 3 statute miles, with light snow and mist.

Icing Information

Current Icing Potential products valid for the time and location of the accident flight indicated a wide range of probabilities of icing for the accident region, with icing severities identified as "trace" and "light.” There was no indication of a super-cooled liquid drop threat for the region.

Calculations by the RAwinsonde OBservation Program (RAOB) indicated scattered and broken stratiform and cumulus clouds may have existed between 7,000 and 13,000 feet. Icing type and severity calculations, based on United States Air Force studies utilizing a 75 percent relative humidity threshold, indicated light rime icing potential between 7,000 and 8,600 feet, as well as in a layer between about 12,700 and 13,000 feet. Icing type and severity calculations made by RAOB indicated light to moderate clear and rime icing potential between 10,000 and 18,400 feet.

Turbulence Information

Vertical wind profile data from the RAOB indicated that the wind was relatively light (15 knots or below) and variable from the surface through 15,000 feet. No significant clear-air turbulence was noted below 18,000 feet.

The Graphical Turbulence Guidance (GTG) was an automatically generated product produced by the NWS' Aviation Weather Center as a supplement to other turbulence advisories such as AIRMETs and SIGMETs. The GTG analysis indicated moderate or greater turbulence could have been expected in the accident area.

WSR-88D Radar Data

Review of WSR-88D base reflectivity data from the Riverton, Wyoming (KRIW) facility, located approximately 36 miles northeast of the accident site, indicated that immediately prior to the accident, the airplane was in, or in the proximity of, a volume characterized by light values of reflectivity. Such reflectivity values in known freezing conditions likely represented suspended snow or super-cooled liquid water drops. At the flight's altitude, the airplane would have come very close to or entered instrument meteorological conditions just prior to the accident.

Eyewitness Observations

A fisherman was on Christina Lake, located just east of the accident site ridge. He heard but never saw the airplane. He stated that the clouds were low, and that it was windy and snowing at that time.

The day after the accident, a snowmobiler was in the mountains in the vicinity of the accident. He stated that it had snowed about 4 to 6 inches on the west side of the ridge, on what was later determined to be the day of the accident.

The airplane was equipped with a Garmin 530 communication/navigation radio with GPS capability. No attempts to establish the operational status of the unit were made, due to damage from the accident. The portable GPSMap 696 unit was operational for the entire trip, and review of that data indicated that the pilot flew direct GPS routes between the departure and destination airports of each leg. That unit was equipped with and capable of displaying a terrain database.

The following text was excerpted from the GPSMap 696 Owner's Manual warnings:

- "The GPSMAP 695/696 is intended only as an aid for VFR navigation. Do not attempt to use this unit for any purpose requiring precise measurement of…location, or topography."

- "Navigation and terrain separation must NOT be predicated upon the use of the terrain function. The GPSMAP 695/696 Terrain Proximity feature is NOT intended to be used as a primary reference for terrain avoidance and does not relieve the pilot from the responsibility of being aware of surroundings during flight. The Terrain Proximity feature is only to be used as an aid for terrain avoidance and is not certified for use in applications requiring a certified terrain awareness system."

- "The displayed minimum safe altitudes (MSAs) are only advisory in nature and should not be relied upon as the sole source of obstacle and terrain avoidance information. Always refer to current aeronautical charts for appropriate minimum clearance altitudes."

- "The altitude calculated by GPSMAP 695/696 GPS receiver is geometric height above Mean Sea Level and could vary significantly from the altitude displayed by pressure altimeters. GPS altitude should never be used for vertical navigation."

Review of the Sectional Aeronautical Chart indicated that the published maximum elevation figure (MEF) in the quadrangle that the accident occurred in was 12,800 feet. It was not determined whether the pilot referenced, possessed, or used any sectional charts for the flight, or whether he was aware of the published MEF.

On December 25, personnel from the Fremont County Sheriff's Office and the FAA accessed the accident site by helicopter to recover the victims and some relevant documentation, and examine the wreckage.

The wreckage was located on a rocky ridge at an elevation of approximately 11,700 feet. The ridgeline was oriented approximately north-south, and the impact location was about 50 to 100 feet below the highest point on that ridgeline within several hundred yards. The surrounding terrain fell away rapidly to the east, and less rapidly to the west. The ridgeline was characterized by a mix of numerous large fragmented rocks and smoother, sloping, snow-covered areas. No trees or other vegetation were present

The engine and propeller pointed approximately west, while the cockpit/forward cabin was oriented approximately nose-down, with the roof facing south. Spanwise, the left wing extended approximately southeast, while the right wing extended approximately northwest.

The airplane sustained significant crush, twist, and tearing deformation, but it was minimally fragmented. Few components or structural items were completely separated from the airframe or engine. All primary components of the airplane were accounted for and recovered, and all were located within the immediate vicinity of the main wreckage. The forward fuselage and cabin exhibited significant crush damage, while the tailcone and empennage were relatively intact. The landing gear was in the retracted position. The flap position was not able to be determined.

Detailed examination of the engine, propeller, and airframe did not reveal any pre-existing mechanical deficiencies or failures that would have precluded normal operation. All damage patterns were consistent with ground impact, with the engine running. Refer to the NTSB public docket for this accident for detailed information.

Supplemental Oxygen Information

Paragraph 91.211 ("Supplemental Oxygen") of the Federal Aviation Regulations required that the pilot be provided with and use supplemental oxygen for that part of the flight that was of more than 30 minutes duration at cabin pressure altitudes above 12,500 feet (msl) and up to and including 14,000 feet (msl), and continuously at cabin pressure altitudes above 14,000 feet. In addition, the regulations required that at cabin pressure altitudes above 15,000 feet, each occupant was to be provided with supplemental oxygen.

Two supplemental oxygen cylinders were located in the wreckage. Both were intact. The larger cylinder remained attached in its normal location inside the center console between the two rear seats. The markings on that cylinder indicated that it had a capacity of 22 cubic feet (625 liters) at a pressure of 1,800 pounds per square inch (psi). Its pressure gauge was intact, and the gauge indicated a pressure of about 1,600 psi. The cylinder was equipped with a fitting with ports for four oxygen lines. Two ports were unused, and two line fittings were installed. One line remained attached to the fitting, while one line was fracture-separated from the fitting.

The smaller cylinder was found loose in the wreckage. The markings on that cylinder indicated that it was a model SK 12-9. Its pressure gauge was intact, and indicated a pressure of about 1,750 psi. That cylinder was equipped with a fitting with ports for oxygen lines; no ports were used.

When respective tank valves were hand-actuated, each tank released gas, presumed to be oxygen, readily.

Two small leather carry-cases were found in the wreckage. Two oxygen mask/line assemblies were found stowed in one case. The other case was empty and zippered closed. Two mask assemblies were found free of the case, in the wreckage. Victim recovery personnel did not provide information on whether a mask was found on the pilot, but the condition of the mask was not consistent with the pilot's injury pattern.

ELT Information

The ELT remained securely mounted in its rack in aft fuselage. The unit was an Artex Model ELT-200, which broadcast on 121.5 and 243 megaHertz (MHz). The external antenna remained attached and in place. In the undisturbed wreckage, the antenna was below and blanketed by the fuselage and the vertical stabilizer.

According to the National Oceanic and Atmospheric Administration (NOAA) website, ELTs were FAA mandated for installation on certain aircraft in the mid-1970s, and those ELTs transmitted on a frequency of 121.5 MHz. That system had several limitations, including frequency clutter, inability to verify the aircraft that was the source of the signal, and the requirement to have another aircraft within range to receive the signal.

In 1982, due to those limitations, implementation began on a satellite-based system that operated on an exclusive frequency of 406 MHz. Key aspects included ELTs with a digital signal that uniquely identified each beacon, and global coverage. Although the receiver satellites were primarily designed to receive the 406 MHz beacons, provisions to receive the existing 121.5 MHz beacons were included. On February 1, 2009, in accordance with an international agreement reached in 2000, satellite reception of 121.5 MHz beacons was terminated. As of August 2012, the FAA has not mandated the replacement of 121.5 MHz ELTs with 406 MHz units.