SEA97FA178
SEA97FA178

HISTORY OF FLIGHT

On July 28, 1997, approximately 1434 Pacific daylight time, a Cessna 172M, N80222, crashed into a residential cul-de-sac in Clackamas, Oregon, a suburb of Portland. The airplane was substantially damaged, and of the three occupants on board, the recently certificated private pilot-in-command and one passenger were killed and one passenger was seriously injured. The seriously injured passenger subsequently died of her injuries on August 28, 1997, 31 days after the accident. There were no injuries to personnel on the ground, and the only damage to property on the ground was to trees and a maintained lawn in the median of the cul-de-sac. The pilot had rented the airplane from Northwest Aircraft Rental (d/b/a Aurora Aviation) of Aurora, Oregon, and the flight was operated under 14 CFR 91. The flight had departed from Aurora State Airport in Aurora, approximately 13 nautical miles southwest of the accident site. Visual meteorological conditions prevailed and no flight plan had been filed.

A fuel slip obtained from Aurora Aviation indicated that the aircraft was refueled at Aurora State Airport at 1406, 28 minutes before the initial report of the accident to emergency dispatch personnel. Some witnesses in the accident area reported that before the crash, they observed the airplane performing maneuvers in the accident area such as decelerating in a 20-degree nose-up attitude, and descending from 800 to 1000 feet above ground level (AGL) to 200 to 300 feet AGL in an uncoordinated turn. Several witnesses further reported that immediately prior to the crash, they observed the aircraft flying slowly at very low altitude (a certificated flight instructor [CFI] who witnessed the accident estimated the aircraft's altitude above the ground as about 40 feet) over the area in the vicinity of the accident site, with some witnesses reporting that they called, or contemplated calling, local authorities to report the low-flying aircraft. Witnesses reported that immediately prior to the crash, they observed the airplane bank steeply (the CFI witness estimated the bank angle of this turn as "in the excess [sic] of eighty degrees"), and that it then dropped steeply nose low and crashed.

The front-seat passenger's brother reported that he was talking to his brother (the front-seat passenger) on a cellular telephone at the time of the accident. The passenger's brother stated that the front-seat passenger told him to come out onto the deck because they were going to fly over. He stated that the passenger then asked him if he could see the airplane occupants waving to him. The brother reported that when he replied he did not, the passenger then told him to wait while they turned around and came back over. The brother told investigators that the last thing he heard on the telephone was a scream, and that he then lost the connection to the passenger. The brother reported that he heard no changes in engine noise and no sounds resembling warning horns during the conversation, and did not indicate that the passenger ever reported any problems with the aircraft during the course of the conversation. The accident site was approximately 3/8 mile east of the front-seat passenger's house.

No communications between N80222 and air traffic control during the accident flight were reported. Investigators attempted to obtain radar data on the accident aircraft from Portland Terminal Radar Control (TRACON) in order to reconstruct the aircraft's flight path during the accident sequence, but Portland TRACON reported that there was no radar data available for the accident aircraft. (NOTE: Portland International Airport, the primary airport for a Class C airspace area and approximately 10 nautical miles north-northwest of the crash site, is at an elevation of 27 feet above mean sea level [MSL]; high terrain rising to approximately 1,050 feet above MSL is situated generally between Portland International and the crash site, approximately 8 1/2 nautical miles from the airport.)

Investigators were unable to interview the surviving passenger before she died, due to the severity of her injuries.

The accident occurred during the hours of daylight at 45 degrees 25.2 minutes North and 122 degrees 32.7 minutes West.

PERSONNEL INFORMATION

The pilot was 19 years old and had recently completed his first year as a student at Embry-Riddle Aeronautical University, Daytona Beach, Florida. The pilot had completed his private pilot training under Embry-Riddle's flight training syllabus in the Socata TB-9 Tampico aircraft. The pilot's first flight was logged on October 28, 1996, his first solo was January 11, 1997, and he had received his private pilot certificate on May 21, 1997, approximately two months before the accident. Training records furnished by Embry-Riddle indicated that the pilot correctly answered a question on a pre-solo written examination, dated November 6, 1996, relating to 14 CFR 91 minimum altitude requirements over congested areas, but incorrectly answered a question on the definition of "careless or reckless operation", giving as his answer "Aircraft operations other than that for the purpose of navigation." The pilot was at home visiting family, which lives in Clackamas, at the time of the accident. The pilot's logbook indicated that he had 86.8 hours total flight time, including 35.5 hours as pilot-in-command, and that he first flew the Cessna 172 on June 17, 1997, approximately six weeks prior to the accident. He had logged six flights in the Cessna 172, for a total of 17.8 hours in that aircraft.

The two passengers on the flight, both 17 years old, also lived in Clackamas and were to have entered their senior year at Clackamas High School, from which the pilot had graduated. The passengers were friends of the pilot from high school.

AIRCRAFT INFORMATION

In a review of the engine logbooks conducted at the operator's facilities, the accident aircraft's engine, a Lycoming O-320-E2D, was found to have 2,172.7 hours since its last major overhaul at the time of the accident. Lycoming service instructions recommend a 2,000 hour time between overhauls (TBO) interval for this engine. The operator stated that due to the engine being beyond its recommended TBO interval, the accident aircraft was not being utilized in air taxi service under Aurora Aviation's 14 CFR 135 operator certificate. In a post-accident examination of the engine conducted at the accident site, investigators found no evidence of an actual mechanical malfunction of the engine.

Compared to the Socata TB-9, the Cessna 172 is of similar weight and power (2,337 pounds maximum gross weight and 160 brake horsepower [BHP] for the TB-9, versus 2,300 pounds and 150 BHP for the Cessna 172), but has a larger wing area (174 square feet for the Cessna 172, versus 128.1 square feet for the TB-9.) As such, at maximum gross weight the Cessna 172 has a lower wing loading (13.2 pounds per square foot for the Cessna 172, 18.24 pounds per square foot for the TB-9, but slightly less favorable power loading than the TB-9 (14.6 pounds per BHP for the TB-9, versus 15.3 pounds per BHP for the Cessna 172.) The Cessna 172's power-off, flaps-up stall speed at 0 degrees bank angle and maximum gross weight ranges from 50 knots calibrated airspeed (KCAS) at the most rearward center of gravity (CG) to 53 KCAS at the most forward CG, while the TB-9's is 58 knots.

At 60 degrees of bank and maximum gross weight, the Cessna 172's flaps-up, power-off stall speed ranges from 71 KCAS at the most rearward CG to 75 KCAS at the most forward CG.

According to a Cessna estimate of the aircraft's weight and balance at the time of the accident, computed from estimated passenger and fuel weights, the aircraft's gross weight at the time of the accident was approximately 2,123 pounds, with a moment of 81,688 inch-pounds. This combination is within the aircraft's allowable weight and balance envelope, with the CG at approximately the 40% point of the allowable CG range at that weight (with 0% being the forward limit and 100% being the aft limit).

The 1976 Cessna 172M pilot's operating handbook (POH) states that maximum altitude loss during a stall recovery is approximately 180 feet.

WRECKAGE

An on-site examination of the aircraft wreckage by investigators from the NTSB, FAA, Cessna, and Textron Lycoming was performed on July 28 and 29, 1997. This examination did not reveal any evidence of pre-impact mechanical problems with the aircraft or engine. The accident aircraft was found resting upright, but leaning toward its right side, on the east edge of the grass median of a residential cul-de-sac, with the nose pointed approximately west. The tail section of the aircraft, largely intact, was broken away from the forward fuselage aft of the cabin and was to the left of the forward fuselage at approximately a 90-degree angle, but remained attached to the forward fuselage by control cables. The right wing remained attached to the fuselage and was bent upward. The left wing remained attached to the fuselage and was largely intact except for a dent in the leading edge approximately 2 feet inboard of the wing tip. The aircraft's flaps were found to be up. A 21-inch section of one propeller blade was broken off. The other propeller blade displayed chordwise scratching, and its tip was bent aft. The engine and propeller (minus the 21-inch section) remained attached to the aircraft.

Approximately 10 feet south of the main wreckage, a major round ground scar with the approximate dimensions of a cross-section of the aircraft's nose was located in the median grass. This ground scar, which was also adjacent to the curb of the median strip, had two curving ground slashes in the grass around its circumference. The remainder of the aircraft's propeller was found buried in this ground scar pattern. The broken-off blade section exhibited chordwise scratching on its back side, leading edge polishing, and slight S-bending. Extending approximately 18 feet to the southeast of the ground scar pattern, on the street pavement, was a generally linear pattern of scratches in the pavement.

Full control cable continuity was established to the ailerons, elevator, and rudder. An on-site examination of the engine performed by the Textron Lycoming investigator, under the supervision of the FAA and NTSB investigators, revealed no evidence of pre-impact mechanical discrepancies with the engine. The aircraft's stall warning horn was tested on-site and found to be functional. Fuel was found on board the aircraft. There was no evidence of fire.

The accident site was approximately 1/4 mile outside the lateral boundary of the Portland class C airspace outer ring. The floor of the Portland class C airspace outer ring in the accident area is 1,700 feet above MSL. The terrain elevation at the crash site was approximately 320 feet above MSL, with the closest hill, Mount Talbert, rising to 740 feet above MSL approximately 2,800 feet northwest of the crash site.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy on the pilot was performed by the Oregon State Medical Examiner's Office, Portland, Oregon, on July 29, 1997. The cause of the pilot's death was listed as head injuries.

Toxicology tests on the pilot were performed by the FAA Civil Aeromedical Institude (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology tests screened for carboxyhemoglobin, cyanide, ethanol, and drugs, and did not detect any of these substances.

SURVIVAL ASPECTS

The crash occurred in a suburban residential area. It was witnessed and emergency aid was called for immediately by local citizens. Emergency response logs indicated that the fire department was on-scene within 9 minutes of call initiation. The two front-seat occupants were determined by emergency response personnel to be dead on arrival. The seriously injured passenger was extracted from the right rear seat and airlifted by helicopter to the Oregon Health Sciences University hospital in Portland; she died 31 days later. All three aircraft occupants were noted to have been wearing their respective occupant restraints, consisting of shoulder harnesses and seat belts in the front seats and seat belt in the rear seat.

ADDITIONAL INFORMATION

14 CFR 91.119(b) specifies the minimum altitude over any congested area of a city, town, or settlement as being 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.

The aircraft wreckage was released to Mr. Bill Bertles, claims representative for Phoenix Aviation Managers, Lakewood, Colorado, on March 11, 1998. Phoenix Aviation Managers is the insurance adjuster firm representing the aircraft owner.

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