N4396RCessna 172M · 1974

On June 28, 2009, about 1510 Pacific daylight time, a Cessna 172M, N4396R, collided with trees during a go-around at Tieton State Airport, Rimrock, Washington. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. The certificated private pilot and one passenger were killed; a second passenger sustained serious injuries. The airplane sustained substantial damage to the forward fuselage and both wings. The personal flight departed Yakima Air Terminal/McAllister Field, Yakima, Washington, at 1441. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot’s wife was waiting at the turf airstrip at Tieton for the airplane to arrive. She was located in her vehicle positioned on the west side of the runway, approximately midfield. She stated that the airplane did not arrive at the expected time, so she drove down to the approach end of runway 02. She waited for an additional 10 minutes and decided to drive back up to her original location. As she approached midfield she caught site of an airplane flying along and above the runway at tree top level. As the airplane passed by her position she observed two people running along the runway edge in the direction of the airplane. She described the weather at the time of the accident to be breezy, and stated that she was concerned that her husband may have difficulty landing in such conditions.

A witness who was located at the runway midfield position stated that she arrived at the airport earlier that day via airplane. She observed a blue and white Cessna 172 approach the airport from over the lake, flying on a northeast heading towards the approach end of runway 02. She was concerned because the approach path was "high" and she considered the airplane to be flying too fast. The airplane did not touch down and continued, "way past" midfield. Once the airplane had reached about 3/4 of the runway length she heard the engine power increase, and assumed the pilot was performing a go-around. From her position it appeared that the airplane then struck trees at the end of the runway. She described the angle of attack of the airplane during the approach and go-around portion of flight to be unusually high. During the go-around the angle of attack of the airplane was such that she could clearly see the full profile of the upper wing surface. She described the weather conditions as, "brisk" gusting winds out of the west, with a temperature of about 80 degrees.

A witness located at the departure end of runway 02 observed the airplane fly over his position. He was concerned that it was low, and he continued to visually follow its flight path. The left wing then struck the top of a tree; the airplane disappeared from his view and he heard a crashing sound.

A review of Federal Aviation Administration (FAA) airman records revealed that the 37-year-old pilot held a private pilot certificate with ratings for airplane single-engine land, issued in January 2008. He held a second-class medical certificate issued in February, 2009, with no limitations or waivers.

An examination of the pilot's flight logbook revealed that the last flight time entry occurred 2 months prior to the accident. At that time, the pilot reported a total of 79.1 hours of total flight experience, with 44.1 hours as pilot-in-command. The pilot's total flight time for the 90 days preceding the accident was 2 hours.

The logbook further revealed that the pilot had flown to Tieton on two prior occasions. For both flights he did not land the airplane at Tieton, but rather returned to Yakima. Additionally, review of the logbook revealed that the pilot's flight experience did not include landings at turf airstrips, or airports located within mountainous terrain.

The four-seat, high-wing, fixed-gear airplane, was manufactured in 1974. It was powered by a four-cylinder, normally aspirated, Textron Lycoming O-320-D2J 160-hp engine, modified by the addition of a RAM Aircraft LP Supplemental Type Certificate (STC) number SA2375SW. The engine was equipped with a McCauley two blade, fixed-pitch propeller.

Maintenance records indicated that an annual inspection was completed on June 12, 2009, 24.4 flight hours prior to the accident.

At the time of the annual inspection the engine had accumulated a total time in service of 396.7 hours since manufacture in November 2007. Additionally, the airframe had accumulated a total time in service of 3,880.2 flight hours. A review of the airplane's maintenance records did not reveal any outstanding squawks or maintenance anomalies.

The closest aviation weather observation station was at Yakima Airport, which was located 24 miles east of the accident site. The elevation of the weather observation station is 1,099 feet msl. An aviation routine weather report (METAR) for Yakima was issued at 1453. It reported calm winds and clear skies, with a temperature of 82 degrees F, dew point of 37 degrees F, and altimeter of 30.02 inches of mercury.

According to first responders from the Yakima County Sheriff department, the weather conditions at the airstrip included a temperature of 77 to 80 degrees F, with a steady wind of about 10 mph, gusting from 20 to 30 mph.

Tieton Airport is a turf airstrip located at an elevation of 2,964 feet on the eastern shore of Rimrock Lake. Runway 02 is 2,509 feet in length and 140 feet wide; it slopes uphill and is abutted immediately to the north by mountains with peaks ranging between 4,400 and 6,500 feet. Trees ranging in height between 50 and 75 feet surround the runway immediately to the east, west, and north.

The FAA Airport/Facilities Directory (AFD), Northwest US, indicated the following for Tieton:

'RUNWAY 02: Trees

RUNWAY 20: Trees

Runway 02 obstructed by mountains at 1000 feet

Runway 20 obstructed by mountains at 1000 feet'

The Washington State Department of Transportation web site, in part describes Tieton Airport as follows:

'The approach from the east is difficult. There is a mountain right on the east end, the runway drops rapidly away to the west, and there are trees in the approach path. Most folks seem to prefer to ignore the wind and land uphill to the east, and depart downhill to the west. We recommend you overfly the field to check conditions, look for obstructions and plan your approach.'

The airplane came to rest within a ravine about 2,200 feet northeast of the departure end of runway 02, at an elevation of 2,930 feet. The terrain immediately to the north of the accident site, in line with runway 02, and about 1 mile beyond its departure end, rises to an elevation of about 4,400 feet. Trees ranging in height between 30 and 100 feet surrounded the area.

The first identified point of contact (FIPC), where the airplane collided with terrain/trees, was located on the top of a tree trunk, which was severed at about the 75-foot level, about 1,300 feet beyond the departure end of runway 02. The elevation of the tree base was about 2,980 feet. A second tree severed at approximately the 30-foot level, was located 800 feet beyond the FIPC, on approximately the runway heading. Several pieces of angularly cut wood, along with the left main landing gear, were located at the base of the tree. The remaining wreckage came to rest at the base of a tree located 20 feet beyond the left main landing gear.

The main cabin area rested on a heading of 350 degrees magnetic. The tailcone had separated aft of the baggage door, remained intact, and was canted about 20 degrees to the right of the forward cabin.

The remaining cabin area sustained crush deformation through to the engine firewall. A child safety seat was located in the aft cabin area. First responders reported that the surviving passenger was strapped into this seat, which was attached to the rear seat belt restraint.

The left wing sustained four semicircular indentations perpendicular to the leading edge. An indentation 6 inches inboard of the wing tip had a measured diameter corresponding to that of the tree trunk located at the FIPC.

The right wing sustained crush damage along its entire leading edge.

The left fuel tank appeared intact, and about 8 gallons of blue colored fuel was drained during recovery. The right wing fuel tank had breached, and contained about 3 gallons of fuel. Both fuel tank caps were firmly in place at their respective filler necks.

An autopsy was conducted by the Yakima County Coroners Office. The cause of death for the pilot was reported as the effect of multiple internal injuries due to blunt impact.

Toxicological tests on specimens from the pilot were performed by the FAA Civil Aeromedical Institute. Analysis revealed no findings for carbon monoxide, or cyanide. The results were negative for ingested alcohol. Acetaminophen was detected in the blood at a level of 3.995 (ug/ml, ug/g). Refer to the toxicology report included in the public docket for specific test parameters and results.

Airframe

The carburetor heat control was noted in the out position, the fuel mixture control was noted full forward. The throttle control was bent down and about 1.5 inches aft of its full forward position. The magnetos switch was set to the both position. The fuel primer pump was noted locked, and in the full forward position.

Measurement of the flap actuator thread extension corresponded to a fully retracted flap position, according to a Cessna Aircraft Company technical representative. Similarly, measurement of the elevator trim actuator thread corresponded to a 5-degree elevator tab up position.

The flight control cables were continuous from the control surfaces through to their respective cockpit controls.

All flight major sections of the airplane were accounted for at the accident site.

Residual amounts of fuel were drained from both the gascolator, and its associated fuel line to the carburetor.

Engine

The engine had become partially buried in soil, and had sustained crush damage to the forward ancillary components and the carburetor intake box.

The two bladed fixed pitch propeller remained attached at the crankshaft flange. The propeller blades remained attached to the propeller hub and the spinner was attached and had sustained crush damage. Both propeller blades exhibited leading edge polishing, nicks, chordwise scratching and tip twist. One blade tip had become separated in a jagged pattern about 3 inches from the tip.

A detailed engine report is included in the public docket for this accident. No anomalies were noted during the inspection.

Fueling records obtained from McCormick Air Center, located at Yakima Airport, revealed that the airplane had been filled to capacity prior to the flight with the addition of 8.1 gallons of 100-low lead aviation gasoline.

Performance

The weight and balance sheet located onboard the airplane revealed a basic empty weight of 1,422 pounds and a useful load of 878 pounds. According to the Yakima County Coroners report, the measured total weight of the front seat occupants was 370 pounds. The weight for the rear seat occupant was 46 pounds. Baggage was observed distributed throughout the cabin, and weighed at the accident site. The total weight of the baggage was 58 pounds.

The RAM Aircraft LP Supplemental Flight Manual appropriate for the airplane and engine states:

'The performance for this airplane equipped with a Lycoming O-320-D2J engine is equal to or better than the original FAA approved performance.'

The performance data was calculated using information from the Cessna Owners Manual applicable to the accident airplane. For the purpose of the calculations, an estimated gross weight of 2,000 pounds was utilized

Using a temperature of 80 degrees F, and an altitude of 5,000 feet, performance charts indicated that at an indicated airspeed of 81 mph, the rate of climb would have been 530 feet per minute.

The Cessna Owners Manual relays the following procedures for performing a baulked landing (go-around).

1) Power -- Full Throttle

2) Carburetor heat -- Cold

3) Wing Flaps -- Retract 20 degrees

4) Upon reaching an airspeed of approximately 65 mph, retract flaps slowly.

The FAA Airplane Flying Handbook (FAA-H-8083-3A) states under the section, Go Arounds (Rejected Landings):

'Attitude is always critical when close to the ground, and when power is added, a deliberate effort on the part of the pilot will be required to keep the nose from pitching up prematurely. The airplane executing a go-around must be maintained in an attitude that permits a buildup of airspeed well beyond the stall point before any effort is made to gain altitude, or to execute a turn. Raising the nose too early may produce a stall from which the airplane could not be recovered if the go-around is performed at a low altitude.

Although the need to discontinue a landing may arise at any point in the landing process, the most critical go-around will be one started when very close to the ground. Therefore, the earlier a condition that warrants a go-around is recognized, the safer the go-around/rejected landing will be. The go-around maneuver is not inherently dangerous in itself. It becomes dangerous only when delayed unduly or executed improperly.'