Aviation Accident Summaries

Aviation Accident Summary SEA97FA043

FORT SMITH, MT, USA

Aircraft #1

N3347Q

Piper PA-28R

Analysis

Although the aircraft initially tracked within the lateral boundaries of a Victor airway during the dark night VFR flight from Billings, Montana, to Gillette, Wyoming, the pilot later veered off course and entered mountainous/hilly terrain. While in cruise flight, the aircraft impacted densely forested rising terrain at 7,800 feet MSL in a near-wings-level attitude.

Factual Information

HISTORY OF FLLIGHT On January 5, 1997, approximately 1930 mountain standard time, a Piper PA-28R, N3347Q, collided with steep rocky terrain about 49 miles southeast of Billings, Montana. The private pilot and his passenger received fatal injuries, and the aircraft was destroyed. The Part 91 personal pleasure flight, which departed Billings-Logan Airport at 1911, was en route to Gillette, Wyoming, at the time of the accident. The aircraft was on a VFR flight plan, and the ELT, which played a role in locating the aircraft, was activated by the impact. According to local authorities, the pilot and his passenger had planned to fly from Gillette to Billings on the day of the accident in order to do some shopping, and their intention was to return to Gillette that evening. At 0714 on the morning of the flight, the pilot called Casper Automated Flight Service Station, and received a weather briefing for the round-trip flight. The aircraft departed Gillette in the late morning and arrived at Billings around noon. Upon arriving at Billings, the aircraft was parked on the ramp while the pilot and his passenger went into town. About 1600, Lynch Flying Service moved the aircraft into a heated hangar in order to warm up the aircraft prior to the pilot arriving back at the airport for his return flight to Gillette. At 1814, the pilot called Great Falls Automated Flight Service Station, and received a weather briefing for the flight back to Gillette. After the briefing, the pilot filed a VFR flight plan, with a routing of direct to Gillette from Billings, an estimated time en route of one hour and twenty minutes, and five hours of fuel onboard. When the pilot arrived back at the airport, an employee of Lynch Flying Service helped him get the aircraft out of the hangar, but the employee was not present when the pilot attempted to get the aircraft started. According to the employee, about ten minutes after the aircraft was taken out of the hangar, the passenger walked over to the Lynch Flying Service office and stated that the aircraft battery was dead, and that they would like a jump-start. The employee then went to the aircraft, used the aircraft's built-in external power receptacle to attach an external power source, and then helped start the aircraft without any problems. According to this employee, the pilot did not say whether he had run the battery down trying to get the aircraft started, or whether the battery had been depleted while he had been in town. After getting the aircraft started, at 1906, the pilot requested to taxi "...for a VFR departure to Gillette Campbell County, at 7,500 feet." At 1911, the pilot was cleared for takeoff on runway 28 right, and at 1916 he was advised by Billings Tower that his flight plan had been activated, and was instructed to contact Billings Departure Control. The pilot then contacted Billings Departure, and received traffic advisories until 1924, when radar service was terminated. When Departure terminated radar service, the pilot requested flight-following for the area, and was told to contact Salt Lake Center on frequency 127.75, and that he could expect Center radar service above 7,500 feet. According to taped time-associated radar tracking data, the pilot had leveled off at just over 7,500 feet at the time Billings radar service was terminated, but he did not contact Salt Lake Center. No further radio transmissions came from the aircraft, and the last 1200 coded radar return coming from the area where the aircraft was flying was recorded at 1926:17, and showed an altitude of 7,700 feet above sea level (MSL). The location of this last "hit" was North 45 degrees, 26 minutes, 16 seconds, and West 108 degrees, 06 minutes, 10 seconds. The position of this hit was located within the lateral boundary of the Victor Airway (V 19/86) that runs between Billings, Montana and Gillette, Wyoming, and was approximately 29 nautical miles southeast of Billings International Airport, and about 21 miles northwest of the accident site. WRECKAGE AND IMPACT INFORMATION The aircraft impacted trees at the 7,800 foot (MSL) level of Peyote Ridge, in the northwest end of the Bighorn Mountains, about 14 nautical miles south southeast of Fort Smith, Montana, and 12 miles south of Victor Airway 19/86. A global positioning system (GPS) unit was used by the Big Horn County Sheriff's Office to fix the location of the site as North 45 degrees, 6.453 minutes, and West 107 degrees, 56.530 minutes. The impact track, which ran through a dense forest on a heading of 155 degrees magnetic, extended approximately 80 feet past the point where the aircraft first impacted a number of coniferous trees. The first ground impact scar was located about 40 feet past the first tree struck by the aircraft, and the propeller was found about two feet past this ground scar. Although part of the left wing tip and a number of small pieces of metal were found at the point of initial impact with the tree, the remainder of the wreckage, except for the propeller, was located within the last 30 feet of the impact track. The fuselage had been torn into three major sections that were aligned along the last 20 feet of the track, and the right wing had folded back and was laying along the right side of the aircraft. The left wing had separated from the fuselage, and except for the wing tip, was found laying to the right of the empennage. The propeller flange had sheared from the crankshaft and was found still attached to the propeller. Both blades were still in the propeller hub, and the spinner, which had been crushed directly back into the hub, was still attached to the spinner attach bulkhead. One blade was essentially straight from the hub to its midpoint, but its outer half was bent aft about 15 degrees, and the last four inches of the tip were bent back about another ten degrees. This blade had numerous leading edge impact indentations along its entire length, with the most severe being concentrated along the outboard one-third of its span. The blade showed chord-wise scarring near its tip, and diagonal scarring along its outboard one-half. A number of deep longitudinal scars ran along most of the length of its span, and the outboard half showed longitudinal twisting of about 10 degrees. The other blade was bent back about 30 degrees just inboard of its mid-point, and the last six inches of the tip was bent back an additional 30 degrees. Although this blade showed no chord-wise scarring or gouges in its leading edge, the last four inches of the tip contained a rounded indentation, and the tip was also longitudinally twisted about 30 to 40 degrees. The wings and their associated flight controls, as well as the fuselage, had been shredded, torn, and ripped apart as they passed through the dense forest. Although there were numerous indentations and dents in all areas of the wings, the most significant damage on both wings was the deep tears where the leading edge metal had been crushed nearly directly backwards almost to the aft spar. The ridges of accordioned metal at the aft end of these tears were aligned within 10 degrees of being perpendicular to the lateral axis of the aircraft. The fuselage aft of the cabin was found in the upright position, but the engine compartment and the forward part of the cabin, which had been torn open, were found inverted. The engine had been forced back into the firewall and its mounts had broken, but it was still attached to the fuselage by cables, hoses, and wires. The starter, alternator, and both magnetos had broken off, but the case was still intact except for an impact fracture just below where the crankshaft exits the front of the crankcase. The crankshaft would not turn due to the damage around the hole in the front of the case. Both magnetos had sustained substantial impact damage and would not produce a spark. All cylinders were still attached to the crankcase, and all cylinder heads were in place. The vacuum pump was still attached, and upon disassembly was noted to have all vanes present, but with impact damage to the rotor. During an examination of the engine, no evidence was found to indicate there were any pre-impact malfunctions or anomalies associated with the engine, turbocharger, or fuel system. A review of the engine log book entries since May of 1992, revealed no history of engine problems. METEOROLOGICAL INFORMATION At the time the pilot received his weather briefing for the return flight to Gillette, Gillette was reporting strong winds, visibility of 20 miles, and an 8,000 foot broken ceiling. The forecast for Gillette during the pilot's expected time of arrival was variable winds at six knots, visibility unrestricted, ceilings around 6,000 broken, with high pressure producing VFR conditions along the route. The forecast for Billings was for winds to be northwest at five knots, visibility unrestricted, 8,000 scattered, and 10,000 broken. The METAR observation taken at Billings at 1856, which was 15 minutes prior to his departure, showed winds 300 degrees at ten knots, 10 miles visibility, 8,000 few clouds, 10,000 feet broken, a temperature of minus four degrees Celsius, and a dew point of minus eight degrees, with an altimeter setting of 30.20 in/hg. Local authorities reported that it was a very dark night, with very little ambient light. It was also reported that at about the time the aircraft departed from Billings, there were widely scattered isolated snow showers around Sheridan, Wyoming, and Fort Smith, Montana. TESTS AND RESEARCH A Garmin GPS 55 was recovered from the wreckage, but no data was recoverable from the unit. Also, a II Morrow Apollo 604 Loran was recovered from the wreckage, and after power was supplied, it was found to be operable. The following information was obtained from the unit: Last Update: North 45 degrees, 07.87 minutes; West 107 degrees, 55.99 minutes ( about one and one-half mile north of the accident site). Initial Position: North 44 degrees, 07.65 minutes; West 105 degrees, 24.96 minutes (near the center of a group of ranch buildings located about 21 miles from the Gillette VOR on the 220 radial). Flight Plan: Initial position direct to Billings, Montana (BIL). There were no other flight plans installed on the unit, and all six user-defined waypoints were in western Montana and Wyoming. The unit did not provide information on the date or time of the flight plan entry. The frequency selector on the navigational radio in aircraft's number one (top) position, a KX-170B that had received impact damage during the crash, was found about halfway between frequencies 115.30 and 115.35. Although none of the VOR's in the area are assigned frequency 115.35, the frequency for the Sheridan VOR (SHR) is 115.30. This VOR is located about halfway between Billings and Gillette (88 miles from Billings, [BIL], and 72 miles from Gillette [GCC]) on the most direct Victor Airway route between the two cities (Victor 9-86 BIL to SHR, and Victor 536 SHR to GCC). Because the co-owner of the aircraft, who was also the instructor for the pilot involved in the accident, said that the pilot normally used the VOR's as his primary navigational instrument (GPS and LORAN only as backup), a course line direct from the accident site to the Sheridan VOR was plotted on the Billings Sectional Aeronautical Chart. This course line (100 degrees magnetic) was exactly the same as the course that was found set under the On Course Index on the VOR indicator head associated with the number one navigational radio. It was also noted that the Course Deviation Indicator on this head was centered over the On-Course Indicator Circle. ADDITIONAL DATA AND INFORMATION The aircraft was released to D. K. Jason & Associates, Ltd., at the site of the accident, on September 11, 1997. An autopsy was performed on the pilot by Kenneth H. Mueller, M. D., of Billings, Montana, on January 8, 1997. The cause of death was listed as accidental due to massive and severe blunt force injuries. The FAA's Toxicology and Accident Research Laboratory completed a forensic toxicology examination on the pilot, and no Carboxyhemoglobin, Cyanide, or drugs were found in his blood. Although 12.00 mg/dL of Ethanol was found in his blood, and 64.00 mg/d of Ethanol was found in his muscle fluid, the report notes that "The ethanol found in this case may be the result of postmortem ethanol production." In addition, 1.00 mg/dL Acetaldehyde was detected in the muscle fluid.

Probable Cause and Findings

The pilot's failure to maintain clearance from terrain. Factors include the pilot inadvertently becoming lost/disoriented, the dark night (minimum ambient light), and mountainous/hilly terrain.

 

Source: NTSB Aviation Accident Database

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