Aviation Accident Summaries

Aviation Accident Summary ATL99FA136

Robbinsville, NC, USA

Aircraft #1

N2820T

Piper PA-28-180

Analysis

"THIS CASE WAS CHANGED FROM ATL05FA014." The non-instrument rated private pilot received an automated flight service station (AFSS) weather briefing for an intended visual flight rules (VFR) direct flight at 6,500 feet over mountainous terrain. After receiving the weather briefing, which included AIRMETs for IFR conditions, mountain obscuration, icing, and low en route cloud ceilings, as well as the advisory, "VFR flight not recommended," the pilot amended his filed altitude to 4,500 feet. The amended altitude was higher than some forecasted cloud ceilings and lower than some of the terrain on the pilot's filed route, and the pilot's filed alternate airport was in mountainous terrain. After takeoff, the pilot did not activate the flight plan or establish radio contact with any air traffic control (ATC) facilities. ATC radar data showed a primary target, presumed to be the accident flight, which was first detected about 2 nm south of the departure airport and continued generally direct toward the destination. Mode C data associated with the primary targets did not begin until about an hour later and continued for 26 minutes. Mode C data were lost when the target was about 15 nm north of the Knoxville Class C airspace at an altitude of 4,600 feet. The airplane was missing for 6 years until is was located by hunters in a heavily wooded mountainous area at an elevation of about 3,300 feet. The accident site was about 12.3 nm north of the destination airport, and about 47.7 nm south of the last Mode C return. Wreckage debris was scattered about 275 feet along an approximate 170-degree magnetic heading from a cluster of trees with uniformly broken tops. Broken tree evidence and impact evidence on the airframe were consistent with level, controlled flight into trees and terrain. Examination of the engine, airframe, and components revealed no evidence of pre-crash malfunction.

Factual Information

"THIS CASE WAS CHANGED FROM ATL05FA014." HISTORY OF FLIGHT On November 4, 1998, at an undetermined time, a Piper PA-28-180, N2820T, registered to PMH Flyers, Inc., and operated by the private pilot, collided with trees and mountainous terrain in the Nantahala National Forest, Robbinsville, North Carolina. The personal flight was operated under the provisions of 14 CFR Part 91 with a visual flight rules (VFR) flight plan filed but not activated. Instrument meteorological conditions (IMC) prevailed at the flight's altitude. The private pilot received fatal injuries, and the airplane was destroyed. The flight departed Greater Portsmouth Regional Airport (PMH), Portsmouth, Ohio, about 1435 eastern standard time (EST) on November 4, 1998, and was missing until October 27, 2004. The flight was en route to Andrews-Murphy Airport (6A3 at the date of the accident, currently RHP), Andrews, North Carolina. According to records from the Automated Flight Service Station (AFSS) in Dayton, Ohio, the pilot telephoned at 1046 EST for a weather briefing and to file a VFR flight plan for a flight from PMH direct to 6A3. The pilot initially reported an intended flight altitude of 6,500 feet above mean sea level (msl) but amended it to 4,500 feet msl after receiving the briefing. According to a transcript of the AFSS briefing, the briefer stated, "it looks like that uh mountain obscuration in the Appalachian chain could persist throughout much of the day. Use caution, mountains occasionally obscured in clouds and/or mist, mostly clouds. Uh there is some IFR forecast along the route also, and it could persist on into the afternoon, ending as late as 21Z [2100 zulu]...this is an AIRMET Sierra...primarily from Henderson, West Virginia, southward to your destination. The potential for this activity is there. Use caution in that respect. I'm required to say VFR flight is not recommended any time there is any potential forecast IFR." There was no known radio communication between the pilot and any air traffic control (ATC) facilities. A review of ATC radar data from the Indianapolis air route traffic control center (ARTCC) showed that a primary target, presumed to be the accident flight, was first detected about 2 nautical miles (nm) south of PMH about 1436 EST. The primary target track was intermittent and continued south, generally along the direct route from PMH to 6A3. Mode C data were not associated with the targets until about 1531, at which time a squawk code of 1200 and an altitude of 4,600 feet was received. About 1537, about 15 nm northwest of Middlesboro-Bell County Airport (1A6), Middlesboro, Kentucky, the target track deviated west and tracked along the Route 119 roadway to 1A6. The target passed directly over 1A6 at an altitude of about 4,500 feet, then continued south on a ground track consistent with a direct route from 1A6 to 6A3. Mode C altitudes varied between 4,500 and 5,100 feet. The last Mode C return was recorded about 1557 and showed the target about 15 nm north of the McGhee-Tyson Airport (TYS), Knoxville, Tennessee, Class C airspace at an altitude of 4,600 feet. No further primary or Mode C returns were received. Indianapolis ARTCC personnel reported that primary radar data capability would not be expected for that location and altitude, however, continued processing of aircraft transponder Mode C data would be expected. After the airplane failed to arrive at its destination, a search was initiated. According to a Civil Air Patrol (CAP) search timeline, an alert notice was issued at 2033 EST, and the CAP was activated at 2303. Extensive air and ground searches did not locate the airplane. On October 27, 2004, bear hunters walking the forest discovered the wreckage and reported it. The wreckage was located in a heavily wooded area on the north side of Rock Creek Knob at an elevation of about 3,300 feet. The site was about 12.3 nm north of 6A3, and about 47.7 nm south of the last Mode C return. PERSONNEL INFORMATION The pilot held a private pilot certificate with a rating for airplane single-engine land and a third-class FAA airman medical certificate issued October 1998 with no waivers or limitations. The pilot's logbook was not recovered for examination. On his application for his most recent medical certificate, the pilot reported 265 total civilian flight hours. A representative of PMH Flyers estimated that the pilot accumulated about 175 hours pilot-in-command time in PA-28 series airplanes. AIRCRAFT INFORMATION The Piper PA-28-180 airplane was manufactured in 1972 and was powered by a Lycoming O-360-A4A 180-horsepower engine, S/N L-16568-36A. The maintenance logbooks were not recovered for examination. A representative of PMH Flyers estimated the airframe had accumulated about 4,600 hours total time and about 90 hours since its most recent annual inspection performed in February 1998. The airplane's hour meter, as observed at the accident site, showed 4924.3 hours. WRECKAGE AND IMPACT INFORMATION Examination of the accident site on November 5, 2004, revealed wreckage debris was scattered about 275 feet along an approximate 170-degree magnetic heading from a cluster of trees with uniformly broken tops. The main wreckage, which consisted of the fuselage and engine, was on the ground about 200 feet south of the initial cluster of broken trees. A swath of treetops along the wreckage path showed evidence of older breaks, and the height of the breaks within the initial tree clusters was relatively level in slope when viewed from the east side of the wreckage path. The airplane's wings were crushed from the leading edge aft, were separated from the fuselage at their respective roots, and were found north of the main wreckage. Broken trees were on the ground with the wing sections. The engine remained attached to the firewall and was displaced aft, down, and to the right. The propeller was separated and found about 3 feet from the engine. Adjacent to the propeller and engine was what appeared to be the moss-covered remnants of a large-diameter tree. The fuselage was resting on its left side and oriented on an approximate 040-degree magnetic heading. The nose landing gear was separated. The middle section of the fuselage floor was buckled upward aft of the front seats. When the fuselage was rolled toward upright, heavy crush wrinkles aft of the firewall were observed on the lower left side. The cabin roof was breached from the glareshield to the aft cabin, exposing the cockpit area. The aft cabin roof was attached and crushed downward. The cockpit door was connected at its hinges to a separated section of the right side fuselage, and the upper section of the cockpit door was crushed and partially separated. The instrument panel was crushed and sections were separated. Puncture marks observed on the cockpit fire extinguisher and displacement of other components were, according to U.S. Forest Service personnel, consistent with wildlife disturbance of the wreckage. The left side control tube and yoke assembly was impact-damaged and separated, the right side control tube was impact damaged with the yoke in place. The aileron control assembly was damaged, and the aileron chain was separated from its sprockets. The inboard end of the right aileron cable was attached to the chain and separated outboard at the wing root. A separated 6-inch section of the left aileron cable was found attached to a broken chain link. The cable separations for the right and left aileron cables showed splaying of the individual cable strands. The floorboard underneath the flap handle was crushed up and aft, the flap handle was between the 0- and 10-degree detents, and the flap mechanism measured 5.25 inches. The front left seat was impact-damaged and attached to the inboard aft attachment. The bottom seat frame was deformed up and aft, and the lap belt buckle and shoulder harness were not latched. Field-testing of the buckle by latching the two buckle ends and tugging on the belt showed the buckle remained fastened when the load was applied; the belt and buckle showed evidence of weather exposure, and latching the buckle was successful on the second attempt. The right front seat was impact-damaged and attached to the seat track. The lap belt buckle and shoulder harness were not latched. Examination of the left wing showed the inboard section was about 20 feet north of the fuselage, the leading edge was crushed aft to the main spar, and the left main landing gear was attached. The flap was damaged and attached at its middle hinge, the outboard flap hinge was attached to the wing. An approximate 6-inch section of the inboard end of the aileron was attached, the bellcrank and push-pull rod were attached, and the aileron stops were in place. Aileron control cable continuity was established from the inboard section of aileron to the wing root. The cable separation at the wing root showed splaying of the individual cable strands. The outboard section of the left wing was about 15 feet north of the inboard section. The outboard section of wing was crushed downward, and the outboard section of the aileron was attached. The pitot mast was attached, and the ram air and static lines, as well as the electrical wiring for the pitot heat, were breached. Examination of the right wing showed it was on the ground near the left wing, and the right main landing gear was attached. The leading edge was crushed aft at an 8-inch diameter semi-circular indentation about 7 feet outboard of the wing root. The flap was damaged, separated, and found about 10 feet north of the wing with the inboard hinge attached; the mid and outboard flap hinges remained attached to the wing. The outboard section of aileron was damaged and attached to a separated section of outboard wing and wingtip. The bellcrank was separated, and about 6 feet of the aileron control cable and about 3 inches of the aileron balance cable were attached to the bellcrank. A section of separated right aileron was found attached to the push-pull rod. A separated section of control cable was also found. All cable separations showed splaying of the individual cable strands. The vertical fin with the upper and mid portion of the rudder attached at the upper hinge was crushed and separated and found about 10 feet south of the main wreckage. An approximate 6-inch section of the lower rudder was attached to the empennage at the rudder horn, the rudder horn was attached, and the rudder stops were in place. Rudder control cable continuity was established from the rudder horn to the cockpit pedal bar. The right side of the stabilator with its corresponding section of trim tab was crushed and separated and found about 25 feet south of the main wreckage. The left side of the stabilator with its corresponding section of trim tab was attached to the empennage. Stabilator control cable continuity was established from the left side of the stabilator to the cockpit t-bar. The stabilator trim mechanism displayed 5 threads, consistent with a neutral trim position. Examination of the propeller showed it was separated from the crankshaft and embedded front side down in a ground crater 16 inches deep. One blade was bent aft about 17 inches from the hub center, and the other blade was bent aft about 15 inches from the hub center. Both blades showed pronounced s-bending and torsional twisting. The leading edge of one blade had two half-inch-deep leading edge gouges, 23 and 26 inches from the hub center. The shape and orientation of the gouges corresponded with the size and shape of a damaged and separated section of the No. 2 cylinder head and rocker box that was found several yards south of the engine and propeller. Examination of the engine revealed the engine mounts were bent down and to the right. The crankshaft was separated aft of the propeller flange. Soil and impacted wood pieces were found embedded in the fins on top of the Nos. 1 and 3 cylinders, the fins were damaged, and the valve pushrods were damaged. The No. 2 cylinder head was fractured with a section of the rocker box separated. The engine sump was fractured with only residual oil remaining. The oil suction screen and the oil filter showed no evidence of abnormal contaminants, and the oil cooler hoses were attached. Rotation of the crankshaft was accomplished by turning an accessory drive, and internal gear and valve train continuity was confirmed. Compression developed on the Nos. 1, 3, and 4 cylinders. The top spark plugs were removed for examination; the electrodes on the plugs from the Nos. 2 and 4 cylinders were coated with oil, dirt, and rust-colored water contamination. The Nos. 1 and 3 plug electrodes showed gray-colored deposits. All four top plugs showed moderate wear and normal gaps. The piston domes and the valves were visually examined using a borescope in the top plug ports with no abnormalities noted. Both magnetos showed impact damage. The left magneto could be rotated and the right magneto could not be rotated, and neither magneto produced spark. Both magnetos showed internal corrosion, and the gears were intact. One tower of the left magneto distributor showed signs of arcing. The alternator was impact-damaged, partially separated, corroded, and would not rotate. The vacuum pump was impact-damaged and fractured at the flange. The shear drive coupling was intact. The pump would not rotate. Internal examination showed the rotor and vanes were intact, and internal corrosion and debris were observed. The carburetor was fractured at the flange and separated, and the mounting bolts were bent forward. The controls were impact damaged; the throttle control was attached, the mixture arm was separated, and the carburetor heat control was separated. The air box was partially crushed. Internal examination of the carburetor showed no obstructions, and the needle valve operated. The fuel pump was fractured, and the internal diaphragms were intact and free of debris. The Aerosonic altitude-encoding altimeter was separated, the glass was intact, and the left half of the instrument face and inside of the glass showed a rust and water stain. The 3-pointer altitude needles corresponded with 6,310 feet, and the Kollsman read 30.01 inches. The unit was recovered for examination. Examination at an FAA-approved avionics repair station revealed the rubber seal was intact, the instrument face was corroded, and the altitude indicating needles and the Kollsman could not be moved. Corrosion of the encoder fitting precluded encoder testing of the unit. Disassembly examination revealed the Kollsman wheel could be turned with the instrument face removed. The sector was impact separated, the pivot was broken, the diaphragm assembly was displaced, and the diaphragms were not ruptured. The pitot mast was removed from the left wing and recovered for examination. Examination by a certificated airframe and powerplant mechanic revealed white-colored corrosion obstructed the pitot and static pressure holes. Both sides of the heating element functioned when electrical power was supplied. The Narco AT150 transponder unit was separated, showed longitudinal and lateral crush damage and case deformation, and the external face and the squawk code dials were missing. The unit was sent to the manufacturer's facility for examination. Damage precluded functional testing of the unit. Examination revealed the internal switch rotors for all four squawk code switches were missing, which precluded determination of the squawk code setting. The manufacturer reported that the on/off function switch was intact and in the "off" position. The Narco ELT 10 unit was found with the external antenna cable connected at the coax connector and the plastic contact separator attached to the cable. The on/off/arm toggle switch was in the "on" position. The external antenna was separated from airplane's empennage at the fitting. MEDICAL AND PATHOLOGICAL INFORMATION Autopsy examination and toxicological testing of the pilot were not performed due to the absence of suitable remains. The pilot's family identified clothing fragments and pursued DNA comparisons of bone fragments recovered from the accident site with known samples obtained from the pilot's home. According to a

Probable Cause and Findings

"THIS CASE WAS CHANGED FROM ATL05FA014." The pilot's improper in-flight decision to continue VFR flight into IMC, which resulted in an in-flight encounter with weather and controlled flight into terrain. Factors were the pilot's inadequate preflight planning and decision-making.

 

Source: NTSB Aviation Accident Database

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