NTSB Factual Report

HISTORY OF FLIGHT

On July 27, 2008, at 1439 Pacific daylight time, a Cessna 172N airplane, N75558, impacted trees and terrain while maneuvering near McMurray, Washington. The airplane was registered to Crest Airpark, Inc., Kent, Washington, and operated by the pilot, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot and two passengers were killed. The airplane was substantially damaged. Visual meteorological conditions prevailed at the time of departure and instrument meteorological conditions prevailed in the area at the time of the accident. No flight plan was filed for the personal flight. The cross-country flight originated from the Roche Harbor Airport (WA09), Roche Harbor, Washington, about 1402, with an intended destination of Auburn, Washington.

A family member of the pilot reported the airplane missing to the Federal Aviation Administration (FAA) on July 27, 2008, after becoming concerned when the airplane had not arrived at its intended destination. The FAA subsequently issued an Alert Notification (ALNOT). The airplane was located by air units on July 27, 2008, approximately 2120, in a heavily wooded mountainous area about 6 miles east of McMurray.

A witness who was flying in a Cessna 170 reported she intended to fly from Blakely, Washington, to Auburn. During the flight, they elected to return to Blakely due to lowering ceilings and decreasing visibility south of Port Townsend, Washington. During the return flight to Blakely, she was receiving traffic advisories from Whidbey Approach Control. The controller advised her about opposite direction traffic. The witness stated that she observed a Cessna that matched the accident airplane passing in front of her position on an eastbound heading. She added that during this time, the visibility to the east of her current position appeared to be "very poor."

There were no known witnesses to the accident sequence.

According to a family member of the pilot, the flight was destined for Auburn to drop off two passengers, pickup one passenger, return to WA09 to pickup two additional passengers, and return to Auburn.

Review of radar data provided by the FAA revealed that a primary radar contact was initially obtained at 1404, about 5.2 miles southeast of WA09 at an altitude of 2,200 feet mean sea level (msl). The flight path of the airplane was generally on a southeasterly heading with at an altitude between 2,400 and 2,500 feet msl until 1420, where a gradual descent to 900 feet msl was observed. At 1427, a slight climb was initiated until approaching the vicinity of Arlington Airport, Arlington, Washington, at 1429. While in the vicinity of Arlington, radar data depicted the airplane initiated a left turn from a southeasterly course to a northwesterly course while climbing to an altitude of 1,700 feet msl. At 1431, the airplane initiated a right turn to northerly course until 1434, where the airplane performed a series of left and right turns with the altitude fluctuating between 1,500 feet msl and 2,900 feet msl. The last three radar returns were consistent with the airplane being in a descending right-hand turn. The last recorded radar return was at 1439, located 0.17 miles southwest of the accident site at an altitude of 2,200 feet msl.

PERSONNEL INFORMATION

The pilot, age 47, held an airline transport pilot certificate with airplane multiengine rating, and a commercial pilot certificate with airplane single-engine land and airplane single-engine sea ratings. In addition, the pilot held a turbojet powered rating and type ratings in various transport category aircraft. A first-class airman medical certificate was issued on November 26, 2007, with the limitations stated, "must wear corrective lenses, not valid for any class after." The pilot reported on her most recent medical certificate application that she had accumulated 14,200 total flight hours.

Review of the pilot's rental records provided by Crest Airpark revealed the pilot had rented a Cessna 172 on seven separate occasions, totaling 12.3 hours of usage between July 5, 2007 and July 17, 2008. Of the seven rentals, six were conducted in a Cessna 172SP and one in a Cessna 172N. According to the rental record, the pilot had rented a Cessna 172SP and Cessna 172N within the previous 90 days to the accident. The total flight time for both rentals was 2.5 hours.

AIRCRAFT INFORMATION

The four-seat, high-wing, fixed-gear airplane, serial number (S/N) 17267807, was manufactured in 1977. It was powered by a Lycoming O-320-H2AD engine, S/N L-4858-76, rated at 160 horsepower and equipped with a McCauley two bladed fixed-pitch propeller. Review of copies of maintenance logbook records showed an annual inspection was completed on April 1, 2008, at a recorded tachometer reading of 2,609.8 hours; airframe total time of 9,935.4 hours; and engine time since major overhaul of 2,559.8 hours. At the time of the accident, the airplane had accumulated 105.2 hours since the time of the inspection.

The engine was overhauled on June 19, 2001, at a total time of 4805.0 hours. According to an entry in the engine logbook, the number four cylinder and number four piston were replaced on August 30, 2007, due to low compression. According to the FAA inspector who interviewed the mechanic that performed the maintenance, the replacement cylinder was removed from another O-360-H2AD engine. Logbooks for the engine in which the cylinder was removed revealed that metal was found in the oil filter and oil suction screen in 2005.

Review of Lycoming Service Instruction Number 1009AT, the recommended time between overhauls is 2,000 hours. The Service Instruction states for the O-320 engine, "if an engine is being used in a 'frequent' type service and accumulates 40 hours or more per month, and has been so operated consistently since being placed in service, add 200 hours to the TBO time."

METEOROLOGICAL INFORMATION

A review of recorded data from the automated weather observation station at Arlington Municipal Airport, Arlington, Washington, located about 11 miles southwest of the accident site reported at 1435; wind from 320 degrees at 7 knots; visibility 10 statute miles; scattered cloud layer at 500 feet above ground level (agl), broken cloud layer at 2,000 feet agl, and an overcast ceiling at 2,700 feet agl; temperature 15 degrees Celsius; dew point 13 degrees Celsius; and an altimeter setting of 30.05 inches of Mercury.

The National Transportation Safety Board's staff meteorologist reviewed weather data and reported that the northwest portion of the National Weather Service (NWS) Weather Depiction Charts for 1200 depicted an area of instrument flight rules (IFR) conditions over Washington in the vicinity of the accident site. Surrounding that area was an area of marginal visual flight rules (MVFR) conditions over portions of western Washington, Oregon, and northern California. The closest visual flight rules (VFR) conditions were depicted over eastern Washington. MVFR conditions were depicted over the route of flight and the accident site, with IFR conditions in the immediate vicinity. The closest station model to the south of the accident site depicted MVFR conditions with a ceiling overcast at 1,900 feet agl. The northwest section of the NWS hourly Radar Summary Chart for 1419 PDT (2119Z) depicted a band of "light" intensity echoes associated with rain showers over the Cascade Range and Puget Sound area, and in the immediate vicinity of the accident site.

The northwest section of the NWS hourly Radar Summary Chart for 1419 depicted a band of "light" intensity echoes associated with rain showers over the Cascade Range and Puget Sound area, and in the immediate vicinity of the accident site.

According to the Skagit County Sheriff Deputy, who was located just north of the accident site, "spotty rain showers" and a "typical marine layer" were present around the time of the accident.

COMMUNICATIONS

Review of communication transcripts provided by Whidbey Approach Control revealed that the pilot initially contacted Whidbey Approach Control at 1408. At 1410, the controller notified the pilot of the accident airplane that he didn't have "anybody go south of bush point in the last hour VFR." The pilot responded to the controller that it "looks pretty good so far." At 1413, the controller informed the pilot to maintain VFR at or above 2,500 feet msl due to other traffic in the vicinity. At 1414, the controller advised the pilot to contact Whidbey Approach Control on 120.70, and the pilot acknowledged. The pilot contacted Whidbey Approach Control at 1415, reporting they were at an altitude of 2,500 feet msl. The controller canceled the altitude restriction for the accident airplane at 1417, followed by an acknowledgment from the pilot.

At 1419, the controller reported to another aircraft in the vicinity that the weather around Seattle extending north 15 to 20 miles was "pretty limited visibility with low ceilings," and subsequently asked if the pilot of the accident airplane copied that radio transmission. The pilot of the accident airplane acknowledged that they heard the controller's transmission and reported that they were going to initiate a descent to 2,000 feet msl. The controller responded, "maintain VFR altitudes your discretion." At 1423, the controller terminated radar service with the accident airplane and informed the pilot to squawk VFR and frequency change approved. The pilot subsequently responded acknowledging the controller's request. No further radio communications were received from the accident airplane.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted trees and terrain within heavily wooded mountainous area about 6 miles east of McMurray at an elevation of 2,214 feet msl. The airplane came to rest on its left side on a heading of about 085 degrees magnetic. The wreckage energy path was measured about 175 feet in length on an approximate heading of 085 degrees magnetic from the first identified point of contact (FIPC) with trees to the main wreckage and engine. Located within the wreckage debris path were various broken trees and wreckage debris. All major components of the airframe, primary flight controls, engine, and propeller were observed at the accident site.

The left and right wings were separated from the fuselage. The right wing was located near the FIPC and exhibited a semicircular impact about 2 feet outboard of the wing root. The left wing and fuselage were located about 100 feet beyond the right wing. The left wing was separated from the fuselage and exhibited leading edge compression throughout its span. The engine was separated from the fuselage and was located about 30 feet beyond the main wreckage.

MEDICAL AND PATHOLOGICAL INFORMATION

The Skagit County Coroner’s office conducted an autopsy on the pilot on July 29, 2008. The medical examiner determined that the cause of death was "blunt trauma injuries."

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested with negative results for carbon monoxide, cyanide, and volatiles. An unspecified amount of Azacyclonol was detected in the urine, however, it was not detected in the blood.

TESTS AND RESEARCH

On August 7, 2008, at the facilities of Precision Airmotive, Marysville, Washington, the Precision MA-4SPA carburetor, serial number 10-5217, was examined by representatives of Precision Airmotive under the supervision of the Safety Board investigator-in-charge (IIC). The examination revealed that the carburetor exhibited impact damage. The mixture and throttle levers were separated. The inlet fuel fitting was finger tight. The fuel inlet screen was removed and found to be free of debris. The right pontoon of the delrin type float was found completely filled with a blue liquid that appeared to be consistent with 100 low-lead aviation fuel. No visible leaks were noted with the pontoon. A blue stain was observed on the inner edge seam at the top of the right pontoon.

On August 26, 2008, at the facilities of AvTech Services, Maple Valley, Washington, the engine and airframe were examined.

Examination of the recovered airframe revealed no mechanical anomalies that would have precluded normal operation. Flight control continuity was established throughout the airframe to all primary flight controls.

Examination of the engine revealed that all of the cylinders remained attached to the engine crankcase. All of the engine accessories were separated from the engine. The top spark plugs and rocker box covers were removed. Mechanical continuity was established throughout the engine and valve train when crankshaft was rotated by hand. Thumb compression was obtained in proper firing order on all cylinders except for number four. The engine was disassembled and visually examined.

No anomalies were noted with the number one, two, and three cylinders.

Examination of the number four cylinder revealed that the exhaust valve was stuck in the open position. Tooling marks were observed on the rocker box casting internal surface next to the exhaust valve spring. The exhaust valve springs and exhaust valve were removed from the cylinder. During removal of the exhaust valve, significant binding was noted. The valve springs visually appeared to be distorted and were intact. The exhaust valve stem was found bent. The exhaust valve guide was found loose within its respective bore within the casting of the cylinder head. The exhaust pushrod was intact and straight. A wear pattern was present around the circumference of the pushrod, consistent with contact against the pushrod tube, which was dented.

The crankshaft was intact and undamaged. All four connecting rods remained attached to the crankshaft and were undamaged. The camshaft was intact and each of the camshaft cam lobes exhibited severe wear and spalling signatures. The corresponding tappets exhibited severe spalling on their respective camshaft contact surfaces.

The single drive dual magneto exhibited damage consistent with impact. When the magneto drive shaft was rotated by hand, spark was produced on each post with impulse coupling engagement. According to the Lycoming investigator, the "e-gap timing was not within specifications" and the points were "opening slightly."

The Lycoming investigator stated that the engine exhibited significant internal wear characteristics consistent with a "high time engine."

No additional anomalies were noted with the engine.

The two bladed fixed pitch propeller remained attached to the crankshaft propeller flange. One of the propeller blades exhibited a slight aft bend about 6 inches from the propeller blade tip. The opposing propeller blade was bent aft and slightly curled.

NTSB Probable Cause

The pilot's improper decision to continue VFR flight into instrument meteorological weather conditions. Contributing to the accident were low ceilings, reduced visibility, and mountainous terrain.