WPR12FA136

The dual instructional flight was operated in an area where light rain, fog, and overcast ceilings were present. As the flight proceeded, it entered a hilly area with steady rain, low ceilings, and dense ground fog that extended to above tree height. While maneuvering in that area, the pilots did not maintain sufficient altitude, and the airplane impacted a tree that was likely hard to see because of the reduced visibility. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

HISTORY OF FLIGHT On March 14, 2012, about 1725 Pacific daylight time, a Cessna 150L, N18677, collided with a tree about 2 ½ miles northwest of Goble, Oregon. The flight instructor and his student received fatal injuries, and the airplane, which was owned and operated by Aero Maintenance Flight Center, of Vancouver, Washington, sustained substantial damage. The local 14 Code of Federal Regulations Part 91 dual instructional flight, which departed Pearson Airport, Vancouver, Washington, about 1620, was being operated in an area where instrument meteorological conditions had been reported. No flight plan had been filed. According to local law enforcement officials, although one individual who lived about 4 miles from the accident site heard abnormal sounds coming from an airplane’s engine during the time period the accident airplane was likely in the area, there were no known witnesses to the crash itself. Therefore a search was not initiated until the operator reported the flight was overdue. Once the search was initiated, an emergency locator transmitter signal was detected, and a follow-up "pinging" of the cell phone of one of the occupants led to the discovery of the wreckage. According to the Aero Maintenance Flight Center’s Rental Dispatch Checkout Form, the expected departure time of the flight was 1500, with an expected return time of about 1700. But, the flight did not depart Pearson Airport until about 1620, and the reason for the delay is unknown. The occupants did not indicate on the dispatch form what their destination was, or what their route would be. They also did not indicate whether they had checked the weather. After the airplane departed Pearson Airport, it was tracked flying to the north by the radar at the temporary Air Traffic Control Tower (ATCT) at Pearson Airport. According to the ATCT quality assurance staff, there were not a lot of low level aircraft flying in that area at that time, so it was easy for them to track the 1200 code of this airplane on the recorded radar data. That data showed the airplane subsequently arrived at Scappoose Airport near Scappoose, Oregon, about 1634. Then about 1649, the radar picked up a 1200 transponder code airplane departing Scappoose Airport and heading to the north, but it could not be confirmed that this was the same airplane. That airplane ultimately landed at Woodland Airport in Woodland, Washington, at 1706, and departed there almost immediately thereafter, flying in a northwesterly direction toward Goble. Ultimately that airplane was lost from radar, but at 0724:30, a 1200 code squawk was picked up about 4 miles south of the Kelso-Longview Airport, which was about 2 miles north of the accident site. The aircraft associated with that squawk was heading to the south, toward the general area of the accident site. It was flying about 1,800 feet mean sea level (msl) and about 60 knots. The track continued toward the location of the accident site for about 75 seconds, during which timethe altitude readout increased to 2,000 feet, and then decreased back down to 1,500 feet. The last radar hit from that track, which was at 1725:44, was about ¾ of a mile north of the accident site, and on a track aligned almost directly with the location where the accident airplane hit the tree. After 1725:44, there were no further 1200 squawk codes in the area where the track had been seen. PERSONNEL INFORMATION The flight instructor, who was sitting in the right seat, was a 47 year-old male, who possessed a commercial pilot certificate, with airplane single engine land, multi-engine land, and instrument ratings. He was rated for flight instruction in single engine land airplanes. According to the operator, he had accumulated about 650 hours total time in airplanes, with about 80 hours being in the make and model involved in the accident. He had accumulated about 46 hours in airplanes in the last 90 days. His last airman’s medical, a class 2, without waivers or limitations, was dated April 8, 2011. The date of his last flight review was not determined. The individual sitting in the left seat was a 17 year-old male, who possessed a student pilot certificate. According to records provided by the operator, he had accumulated 18 hours in single engine land airplanes, all of which were in the make and model involved in the accident. Of those 18 hours, 9 were accumulated in the 90 days prior to the accident, and 5 had been accumulated in the 30 days prior to the accident. His most recent airman’s medical, a class 3, without waivers or limitations, was dated September 22, 2011. AIRCRAFT INFORMATION The airplane was a 1972 Cessna 150L, with a Continental Motors O-200-A, 100 horsepower motor, and a McCauley 1A100/HCM6948 fixed pitch propeller. At the time of the accident, the airplane had accumulated 13,527.2 hours since new. The engine, which underwent a major overhaul on February 29, 2012, about 16 days prior to the accident, had accumulated 2.2 hours since the signoff of the overhaul. According to the operator, this was the first revenue producing flight since the overhaul. METEOROLOGICAL INFORMATION The Portland International Airport (KPDX) recorded aviation weather surface observation (METAR) for 1553, which was about 28 minutes prior to the takeoff from Pearson Airport, indicated a wind from 100 degrees at 7 knots, 10 miles visibility, a broken ceiling at 2,800 feet, an overcast at 3,700 feet, a temperature of 6 degrees C, a dew point of 4 degrees C, and an altimeter setting of 29.82 inches of mercury. The KPDX METAR for 1653, which was about 33 minutes after the takeoff from Pearson Airport, indicated a wind from 110 degrees at 10 knots, 10 miles visibility, light rain, a broken ceiling at 2,900 feet, an overcast at 3,700 feet, a temperature of 6 degrees C, a dew point of 4 degrees C, and an altimeter setting of 29.84 inches of mercury. The 1553 METAR for Scappoose, Oregon, which is located about 15 miles northwest of Pearson Airport, and 16miles south of the accident site, indicated a wind of 150 degrees at 4 knots, a visibility of 6 miles, light rain, fog, a broken ceiling at 2,000 feet, an overcast at 2,500 feet, a temperature of 8 degrees C, a dew point of 7 degrees C, and an altimeter setting of 29.81 inches of mercury. The 1653 METAR for Scappoose, Oregon, which was taken about 32 minutes prior to the crash, indicated a wind from 100 degrees at 5 knots, 5 miles visibility, light rain, fog, an overcast ceiling at 2,200 feet, a temperature of 8 degrees C, a dew point of 7 degrees C, and an altimeter setting of 29.81 inches of mercury. The 1655 METAR for Kelso, Washington, which is located about 8 miles north of the accident site, indicated a wind from 140 degrees at 11 knots, gusting to 14 knots, 10 miles visibility, scattered clouds at 4,100 feet, scattered clouds at 4,700 feet, an overcast ceiling at 6,000 feet, a temperature of 8 degrees C, a dew point of 6 degrees C, and an altimeter setting of 29.80 inches of mercury. The 1715 METAR for Kelso, Washington, which was taken about 12 minutes prior to the accident, indicated a wind from 150 degrees at 10 knots, visibility 10 miles, an overcast ceiling at 6,000 feet, a temperature of 8 degrees C, a dew point of 6 degrees C, and an altimeter setting of 29.80 inches of mercury. In an interview with the NTSB Investigator-In-Charge (IIC), the individuals who owned the property on which the accident took place stated that very often in the winter months, when the wind was blowing from the east or southeast, the fog that built up over the Columbia River would be blown up over the hills east of the river around the Goble area. They said that on the day of the accident, and for about two days prior, such an event had occurred, and therefore in addition to the steady light rain that had been falling that afternoon; a thick fog had rolled in that limited the visibility to about ¼ mile. In addition to their statements, the owners were able to provide the IIC two security camera photos, both of which were taken about 25 minutes prior to the crash. Both photos make it clear that there was a thick fog covering the ridge, which reached from ground level to above the top of the trees in the area near where the airplane impacted both the tree and the ground. Based upon measurements taken at the scene, the IIC estimated the horizontal visibility through the fog to be about ¼ mile. Another individual, who lived along the west edge of the Columbia River, about 4 miles north-northwest of the accident site, at an altitude of 100 feet above sea level (about 900 feet lower than the accident site), reported that there were low clouds at his location, and that there was a steady rain during the 45 minutes prior to the accident. As part of the investigation, the IIC contacted Lockheed Martin Flight Services, and both contract providers of the Direct User Access Terminal Service (DUATS) to determine if anyone associated with N18677 had made use of theirweather briefing products on the day of the flight. According to representatives of all three entities, no such services had been provided. WRECKAGE AND IMPACT INFORMATION The initial point of impact was where the airplane’s right wing collided with a tree trunk near the top of a 100 foot tall tree on heavily forested up-sloping terrain. The base of the tree was at the 960 foot level of a north/south running ridge, which topped out at about 1,200 feet. Upon impacting the tree, the airplane’s right wing was sheared off outboard of the middle aileron attach hinge. The wing structure from that point outward, along with the entire aileron, was located in or near the tree. From there, the airplane traveled about 415 feet further, on a track of 200 degrees, whereupon its left wing tip impacted the surface of a soft grassy meadow. The airplane came to rest about 15 feet past the wing tip impact point, at 46 degrees, 01 minutes, 50.99 seconds north, 122 degrees, 55 minutes, 20.61 seconds west. Except for the portion of the wing structure that had sheared upon impact with the tree, all major structural sections of the airframe and engine were present at the aforementioned wreckage location. The forward part of the fuselage, from a point just aft of the rear window, was positioned in a 45 degree nose down attitude, with the propeller and front part of the engine embedded into the soft wet dirt of the meadow to a point just aft of the forward two cylinders. The nose landing gear strut had separated from the fuselage, but both main landing gear, with their associated wheels and tires, where still attached. The aft portion of the fuselage had torn loose from the forward portion around about 60 percent of the first riveted bulkhead seam aft of the rear window. The portion of the seam that failed was located across the top of the fuselage and down both sides, with the belly portion of the seam remaining intact. From this failed seam aft, the fuselage was bent downward about 30 degrees from horizontal, with the aft tip of the empennage resting on the ground. Both the forward and aft spars of both wings were still attached to their respective spar carry-through attach fittings on the fuselage, and both ends of the wing lift struts on each wing were still attached to their respective fittings. The primary damage to the left wing was near its tip, where the leading edge had been crushed aft on a diagonal line starting about 3 feet in from tip, where it was forced aft about 1 inch, to a point at the tip of the wing, where it was crushed aft almost to the aft wing spar. The remainder of the wing had retained its primary structural form. The right wing, from a point just inboard of the separation, retained its primary structural form, except where the aileron control cables had been pulled through the upper skin to a point adjacent to the outboard end of the flap. Near the point of separation, the leading edge was crushed aft, and the wing spars and internalstructure were bent, twisted, and torn. The portion of the wing that separated upon impacting the tree revealed a rounded semicircular aft crushing indentation about 18 inches in diameter, which extended from the leading edge to just in front of the aft spar. The vertical axis of the crush was perpendicular to the span of the wing, which is consistent with a near wings level roll attitude. The depth of the crush on the bottom of the wing was about three inches further aft than that on the top of the wing, which is consistent with a slight nose up pitch attitude. The inner surface of the crushed structure contained numerous small splinters of wood as well as crushed tree bark. Fuel was recovered from both wing fuel tanks, with about 5 gallons coming from the left, and about 3 gallons from the right. Both the right and left flaps were still attached to their wing fittings, and the left aileron, which was undamaged, was still attached to its wing by its three hinges. The right flap was in the full up position, but the left flap, which was buckled and twisted along the inboard half of its span, was found extended about 10 degrees. An examination of the flap actuator mechanism revealed that it was in the flaps up position. The empennage and all of its associated stabilizer and flight control surfaces were undamaged, and the elevator trim tab actuator, which was measured at 1.75 inches extension, was indicative of a 5 degree tab up (nose down) position. Flight control continuity and function was established to all flight controls, except for the separated right aileron, where continuity and function was established only out to the aileron actuator rod. An examination of the instrument panel revealed that the ignition key was in the “ON” position, the cabin heat was partially on, the mixture was in the full rich position, the carburetor heat was in the full on (out) position, and the throttle was out about 2.1 inches. The shafts of both the carburetor heat and the throttle had both been bent to the right at the point where they exited the instrument panel. The engine primer was in and locked. Both the communications radio and the navigation radio were in the “ON” position, and the transponder code was set to 1200. At the conclusion of the on-scene portion of the investigation, the airplane was recovered to the facilities of AvTec Services in Auburn, Washington, for further investigative activities, with an emphasis on an examination of the engine and its accessories. The propeller and spinner remained attached to the engine during the examination. One propeller blade displayed a series of widely spaced shallow chord-wise scratches, which ran from the leading edge to near its trailing edge, along the majority of its span. Along the leading edge of the same blade, just forward of about 6 of these scratches, were small nicks in the metal surface of the blade. In addition, along portions of the span, the paint just aft of the area of normal operationalabrasion was burnished away almost to the bare metal. The other blade, which was found protruding from the ground at the accident site, also displayed an area or non-operational paint burnishing on its most inboard 1 foot. The remainder of its span did not display any chord-wise scarring or leading edge damage. The spinner, which was crushed almost directly aft into the propeller hub, showed a small number of short circumferential scratches, and had rotated slightly so as to be in contact with the leading edge of both blades. Because of the impact angle, the air inductions system, the mufflers, and the exhaust pipes displayed varying degrees of impact damage. The oil sump had been crushed from the rear and was torn open. The rocker covers were removed, and the crankshaft was rotated by hand, establishing positive valve train continuity and cylinder compression at the spark plugs holes. The cylinders were boroscoped, and the pistons and the combustion chambers exhibited normal light grey combustion deposits. The cylinder overhead components were lubricated, with no signs of thermal stress or damage. The crankcase was undamaged. With the rotation of the crankshaft, the magnetos rotated freely, and the sound of the impulse couplings engaging and releasing could be heard. Visible spark was able to be generated from sparkplug ends of all ignition leads. The top spark plugs were removed and examined. All four plugs showed a thin coating of normal light grey combustion deposits, with normal wear patterns. There was no indication of particle contamination, shorting of the electrodes, or cracks in the insulators. The carburetor, which was undamaged, was removed and disassembled for examination. The mixture and throttle linkage was able to be moved freely by hand. The right float had minor compression damage to its outboard side, but the float pivot point was able to be moved freely by hand, and there was no visible indication of punctures or breeching of the floats themselves. The float assembly was held underwater and compressed, but there were no air bubbles indicating air escaping from either float. The float bowl, which was free of debris, showed no indication of float-to-sidewall rubbing, and it was holding approximately 1 ounce of light blue aviation fuel. The float needle valve was removed, and the valve tip and the valve seat showed normal wear patterns, with no signs of damage. The inlet finger screen was intact and free of debris. The accelerator pump was tested by putting water in the bowl and actuating the throttle linkage, whereupon water squirted from the pump jet. Although the oil sump had been breached, the oil pickup tube and screen could be seen. The screen was unobstructed. The spin-on oil filter was removed and the element was cut in a manner where it could be laid out flat. No abnormal metallic particles or contamination was noted. The vacuum pump was removed and disassembled. The drive coupling rotated freely, and the rotor andvanes were undamaged. There were minor chatter marks on the interior walls, but there was no abnormal contamination or other anomalies noted. At the time of the completion of the engine examination, no abnormalities or anomalies had been observed that would have prevented the engine from operating normally and producing rated horsepower. MEDICAL AND PATHOLOGICAL INFORMATION The office of the Oregon State Medical Examiner performed autopsies on both occupants. The manner of death for both occupants was listed as accidental. The cause of death for the student pilot was listed as blunt force head injuries. The cause of death for the instructor pilot was listed as blunt force head and chest injuries. The Federal Aviation Administration’s Civil Aerospace Medical Institute performed forensic toxicological examinations on samples taken from both occupants. The examinations on both occupants were negative for carbon monoxide, cyanide, ethanol, and for all prescription and non-prescriptions drugs screened.