Big Bear Lake, CA, USA
N8719N
Piper PA-28-140
The airplane impacted steep mountainous terrain while climbing after departure approximately 5 miles to the southwest of the departure airport. The airport was surrounded by 7,600-foot to 8,000-foot mountain ridges to the north, south, and east. To the west was a 6-mile-long lake ending in a dam and then a descending valley. Weather was clear skies with winds from the southwest at 6 knots. The pilot flew a southwestern departure route from the airport that crossed rugged mountainous terrain within 5 miles of the airport. This route was not the departure route recommended by the Big Bear City Airport; however, this pilot had recommended this route to at least one other pilot he had flown with in the past. The pilot misjudged the altitude required to cross these mountains and collided with terrain. No preaccident anomalies were noted with the airplane or engine. Toxicology lab results indicated that the pilot had been exposed to marijuana within the 10 hours prior to the flight. Medical analysis indicated that the pilot may have been somewhat impaired by the affects of marijuana, but it is unclear what role such impairment might have played in the decision making that set the stage for this accident.
HISTORY OF FLIGHT On April 6, 2003, about 1630 Pacific daylight time, a Piper PA-28-140, N8719N, collided with trees and mountainous terrain approximately 5 miles southwest of Big Bear Lake, California. A friend of the pilot owned the airplane and was operating it under the provisions of 14 CFR Part 91. The commercial pilot and one passenger received fatal injuries. A second passenger received minor injuries. The airplane was destroyed. The flight originated at Big Bear City airport at 1615, and had a final destination of San Diego, California. Visual meteorological conditions prevailed, and the pilot received a weather briefing. No flight plan had been filed. The airplane's wreckage was at 34 degrees 13 minutes 10.1 seconds north latitude and 116 degrees 56 minutes 14.5 seconds west longitude. The Big Bear City airport elevation is 6,748 feet mean sea level (msl). The four-place airplane was carrying 3 persons and 107 pounds of baggage. The surviving passenger stated that the pilot told her that they would not get a full load of gas before leaving Big Bear. They would stop at Palomar Airport, Oceanside, California, to fuel up before continuing on to Montgomery airport in San Diego. Fuel receipts indicate that the pilot did take on 6 gallons of fuel at Big Bear City before departure. They took off from runway 26 and flew over the lake. The survivor did not notice the turn to the south that would take them to the accident location. The survivor also stated that everything seemed normal during the flight until just seconds before the accident when she thought that they were "low over the land." PERSONNEL INFORMATION The pilot obtained his first-class medical certificate with no limitations on October 7, 2002. On November 17, 1998, the pilot was issued a private pilot certificate. On July 24, 2000, the pilot was issued a commercial airplane multiengine pilot certificate. On December 29, 2000, the pilot was issued a commercial pilot certificate with single engine land, multiengine land, and instrument airplane ratings. The pilot held a certified flight instructor certificate. Examination of the pilot's logbook revealed that on January 2, 2003, the pilot completed a biennial flight review, and had accumulated 1,189 flight hours at the time of the accident. The pilot had flown this airplane in and out of Big Bear one other time, on June 7, 2002. AIRCRAFT INFORMATION A 150-horsepower Lycoming O-320-E2A engine, serial number L25039-27A, powered the low wing airplane. Examination of the airplane maintenance logbook revealed that the last annual airframe and engine inspections were performed simultaneously on October 1, 2002, with 1,533 total engine hours and 4,985 total airframe hours. Wing root vortex generators had been installed on February 2, 1998, in accordance to STC SA12166L. METEORLOGICAL INFORMATION At 1600, the Big Bear City airport Automatic Weather Observation System (AWOS) recorded clear skies; 10 miles visibility; temperature 51 degrees Fahrenheit; dew point 15 degrees Fahrenheit; wind from 240 degrees at 6 knots; and an altimeter setting of 30.05 inHg. Winds aloft, recorded by the Moreno Valley, California, South Coast Air Quality Management District at 1600 and 7,000 feet mean sea level (msl) were from the northwest at 10 knots. The survivor stated that the winds appeared to be calm when she egressed from the airplane after the accident. The density altitude calculated for 51 degrees Fahrenheit and 7,000 feet msl was 8,000 feet. AERODROME INFORMATION Big Bear City airport (L35) is nestled in a mountain valley at an elevation of 6,748 feet msl. The asphalt runway (04-26) has a length of 5,850 feet. Departure from runway 26 takes aircraft over Big Bear Lake. The normal departure route taken from runway 26 is to fly westerly over the lake and cross the Big Bear dam. The terrain then descends into San Bernardino and the greater Los Angeles basin. To the north of Big Bear Lake is an 8,000-foot mountain ridge; to the south is a 7,800-foot mountain ridge; to the east is a 7,600-foot mountain ridge; and to the west, the 6-mile-long lake ends in a dam and a descending valley. The preferred arrival and departure routes are available to pilots in the form of a printed handout. The departure route for runway 26 depicts a 10-degree left turn for a route of flight westerly out over Big Bear Lake to cross over the dam, remaining at or below 8,500 feet msl. WRECKAGE AND IMPACT INFORMATION The airplane's wreckage was at an elevation of 7,500 feet msl in mountainous terrain. The mountain ridgeline where the accident occurred is the last major mountain terrain feature before the terrain descends towards San Bernardino in the greater Los Angeles basin. The accident site was located on the northern face of a ridgeline approximately 2 miles southwest of Big Bear Lake, which is the southern boundary of the greater Big Bear Lake valley. The elevations of the ridgeline above the accident site averaged 7,800 feet msl. The minor mountain ridge closest to the wreckage had an elevation of 7,600 feet. Mature pine trees averaging 80 to 100 feet in height and 4 feet in diameter populated the rugged sloping terrain leading to the accident site. Thick underbrush, boulders, and rock outcroppings the size of automobiles covered the ground. A descending path of severed pine treetops and branches, oriented on a magnetic bearing of 262, led to the wreckage. Two large pine trees located on the small ridge above the airplane wreckage were missing branches about 60 feet up. This was the first identified point of unusual foliage/terrain disturbance. Freshly broken branches were below the trees and were approximately 3 inches in diameter. From this initial location there was a path of disturbed trees on the magnetic bearing of 262 degrees that lead down to the airplane wreckage. This bearing led down hill into a small valley with a terrain slope of about 25 degrees. Approximately 120 feet from the airplane wreckage, along the line of disturbed trees, the outboard third of the left wing was in a pine tree about 30 feet above the ground. The wing leading edge wrapped squarely around the tree with the upper and lower wing surfaces parallel to the ground. Two trees, adjacent to that tree, were both topped at the same elevation. Freshly broken branches were on the ground directly below these trees. Approximately 10 feet from the wreckage was a very large pine tree about 5 feet in diameter that displayed a large oval shaped area of crushed and splintered bark about 8 feet above the ground. Distinct slash cut marks radiated from the center, and an area of twisted wood grain abrasion about 8 inches in diameter was to the right of the center of the oval area. The left main landing gear was along the line of disturbed trees about 180 feet from the main wreckage. A center section of the left wing, a section of the left wing fuel tank, and the left wing spar were all 30 to 45 feet from the main wreckage along the disturbed tree line course. The airplane was upright with the fuselage on a magnetic bearing of 021 degrees. The right wing and right main landing gear were attached to the fuselage. Two semicircular indentations were evident along the leading edge of the wing; one close to the wing root and another about 1-foot inboard of the wing tip. The right main landing gear displayed green and brown color transfers and indentations. The right wing fuel tank drain valve had wood splinters embedded into the grooves and in the drain hole of the valve. The empennage and tail section were intact with very little evidence of damage. The elevator trim tab appeared to be in the full up position. The remaining section of the inboard left wing separated from the fuselage and was 2 feet from the airplane's right side. The outboard portion of the wing from the midspan leading edge to the wing spar extending outward to the wing tip was missing. The left aileron was not present with the wing. The left aileron bellcrank was in the left wing and the flight control cables ran from the left wing to the main fuselage cockpit floor decking area. The engine, cowling, and nose wheel detached from the fuselage. They twisted to an inverted position, offset to the left of the airplanes centerline at about 80 degrees, and pivoted around an attach point at the far left edge of the firewall. The nose wheel pointed skyward. Numerous personal bags, various luggage items, a pair of skis, and two sets of ski boots were aft of the passenger seats in the empennage and tail section. The San Bernardino County Coroner recorded that the total weight of the baggage was 107 pounds. MEDICAL AND PATHOLOGICAL INFORMATION: The Riverside County Coroner's department conducted an autopsy on the pilot. According to the coroner's report, the pilot died of blunt force injuries of head, neck, and chest, and they noted no preaccident anomalies. Toxicological test results on the pilot revealed; 0.0019 (ug/ml,ug/g) tetrahydrocannabinol detected in blood, 0.0218 (ug/ml, ug/g) tetrahydrocannabinol carboxylic acid detected in blood, and 0.0724 (ug/ml, ug/g) tetrahydrocannabinol carboxylic acid detected in the liver. Less than 0.05 mg/l of diazepam was detected in blood. SURVIVAL ASPECTS: The survivor was able to use her mobile cell phone to request help. The San Bernardino County Sheriff Department was able to respond with a helicopter. The survivor's description of her location enabled the Sheriff's Department to locate and evacuate her before nightfall. TESTS AND RESEARCH The National Transportation Safety Board investigator-in-charge (IIC) examined the wreckage at the accident site and at Aircraft Recovery Services, Pearblossom, California. Airframe The IIC traced the flight control system cables from the cockpit tunnel to the ailerons, rudder, elevator, and elevator trim tab to their appropriate attach points. The flaps were in the fully retracted position, the control lever and associated cable, chain, and sprocket corresponded to this position. The elevator trim tab deflected upward. The elevator trim drum screw was extended 1.75 inches. Fuel was in the right tank. The left fuel tank had been ruptured, but portions of the tank exhibited bulges. The gascolator bowl detached from the mount and was next to the engine. The fuel line leading to the carburetor detached from the carburetor. A few drops of fuel were in the carburetor bowl. Engine The engine control cables were connected to the carburetor. The air box was sufficiently damaged as not to be able to determine the carburetor heat position prior to impact. The exhaust manifolds exhibited ductile bending. The spark plugs were clean with no mechanical deformation. The electrodes exhibited a light gray color corresponding to normal operation per the Champion Aviation Check-A-Pug AV-27 chart. A borescope inspection revealed no mechanical deformation on the valves, cylinder walls, or internal cylinder head. The engine rotated freely, and the valves moved in firing order. The fuel pump plunger moved up and down, and the gears in the accessory case turned freely. Investigators achieved thumb compression on all cylinders in firing order. Investigators manually rotated the magnetos, and both magnetos produced spark at all posts for each cylinder. The vacuum pump drive coupling separated into two halves, and the vacuum pump cylinder and vanes exhibited fractures. No rotational scoring was on the interior of the drum. The oil sump screen contained black flake-like debris. Investigators inspected the oil filter for metal debris, and found none. The fuel pump's rubber diaphragm was unbroken. Propeller The propeller, Sensenich 74DM6-0-58, S/N K31919, had chordwise striations and leading edge polishing on both blades. Blade tips twisted opposite the camber from the leading edge. Tree bark organic transfer similar in color to the observed local pine trees was evident on the blades. The propeller spinner had a clockwise crushing twist with organic material, of the same color as the material on the propeller, embedded in the metal folds. Weight and Balance The San Bernardino County Coroner measured the weights of the victims and all the baggage removed from the airplane. The surviving passenger's weight was from her driver's license. The Piper technical representative calculated a weight and balance based on the pilot, passenger, and baggage weight with an estimated partial fuel load of 34 gallons. He calculated that the airplane's weight was 2,094 pounds, and the center of gravity (CG) was +89.25in. The weight and CG limits provided by Piper are 2,150 pounds gross weight with a CG between +84.0in to +95.9in. Airplane Performance Using airplane performance charts provided by Piper Aircraft, the PA-28-140 at a gross weight of 2,094 pounds and an altitude of 8,000 feet msl, should be capable of a 340 feet per minute rate of climb. The Power vs Density Altitude chart provided in the Pilot's Handbook estimated that at 8,000 feet msl the engine would have been capable of producing approximately 68 percent power at 2,500 rpm. ADDITIONAL INFORMATION Interview with a friend of the pilot An interview with a pilot, who had flown with the accident pilot in the past, revealed that the accident pilot had tried to fly a southwesterly departure out of Big Bear in the friend's airplane on March 20th. The friend and owner of the airplane rejected the idea in preference to the standardized departure route over Big Bear Lake. According to the friend, the pilot was strongly urging the taking of the southwesterly route in order to save time. Information Available to the Pilot The Aeronautical Information Manual (AIM) in Section 5, subpart 7-5-1.a, lists the 10 most frequent causes of aviation accidents that involve the pilot-in-command. Listed at numbers 7 and 8 respectively are "Improper inflight decisions or planning" and "Misjudgment of distance and speed." Subpart 7-5-1.c, specifies the lack of alertness during good weather as a common mishap factor due to a feeling of enhanced security. Subpart 7-5-5.a, includes a lengthy discussion of mountain flying and the general recommendation to approach mountain passes with as much altitude as possible. The IIC released the wreckage to the owner on August 8, 2003.
the pilot's inadequate decision regarding a departure route and his failure to maintain clearance with rapidly rising mountainous terrain. A factor in the accident was the pilot's impairment by the effects of exposure to marijuana within the 10-hour period prior to the flight.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
