ANC98FA116
ANC98FA116

HISTORY OF FLIGHT

On August 5, 1998, at 1605 Alaska daylight time, a float equipped Cessna A185F airplane, N5314R, was destroyed when it impacted terrain about 24 miles northeast of Ketchikan, Alaska, at position 55 degrees 30.98 minutes North latitude, 131 degrees 01.17 minutes West longitude. The commercial pilot and one passenger sustained serious injuries. The remaining passenger sustained fatal injuries. The flight was operated under 14 CFR Part 135, by Taquan Air Service, Inc., of Ketchikan, as an on-demand sightseeing flight. Visual meteorological conditions prevailed at the time of the accident, and a company VFR flight plan was filed. The flight departed the Ketchikan Downtown Seaplane Base at 1455, on a planned 1.5 hour sightseeing tour of Misty Fjords National Monument. Company dispatchers began attempting to contact the airplane at 1630, and declared the flight overdue at 1655. Pilots in the area of the accident site reported hearing an emergency locator transmitter (ELT) signal on 121.5 MHz. The wreckage was located at 1742.

The pilot told the NTSB investigator-in-charge (IIC) during an interview on August 6, that they had flown for 40 to 45 minutes, and landed at the confluence of the East Arm, and the West Arm, of Rudyerd Bay, locally referred to as "The Y." A normal part of the tour was to land on the water along the route, and allow passengers out on the floats to take photographs. To do this, the pilot had to slide his seat aft, get out, and allow the right front seat passenger to exit. He indicated that when he did so, he pinched the feet of the rear seat passenger, who had her legs stretched out behind his seat. After a few minutes, he reseated the front seat passenger, and took off.

The pilot said that after taking off from "The Y," about ten minutes elapsed before the engine quit. The rear seat passenger, during three separate interviews, told the Alaska State troopers, and the NTSB IIC, that there was no warning prior to the engine "sputtering and stopping." She indicated the pilot acted surprised.

The pilot told the Alaska State Troopers on August 6, and the NTSB IIC on August 7, that while climbing up the Ella Lake drainage, about 800 feet msl, the engine suddenly quit. He said he turned on the fuel boost pump, and nothing happened. He looked down and saw the fuel selector valve handle on the "LEFT" position, so he turned it to "BOTH." He indicated the airplane was too low to clear the trees ahead of them and land on Ella Lake, so he reversed direction to glide to lower terrain. The engine did not restart, and he did not have time to extend the trailing edge flaps before the airplane contacted trees and marshy terrain.

The pilot had returned to Ketchikan from an earlier charter flight at 1435, and tied the airplane with the right wing over the dock. He requested a dispatcher have the right wing tank filled, and she called the float plane dock and made that request. The pilot said during an interview on August 7 with the NTSB IIC and FAA coordinator, that prior to departing on the accident flight, he noted the right wing tank was filled, and the 40 gallon left tank was between 1/8 and 1/4 full.

According to the field notes of the NTSB IIC, and the notes of the FAA inspectors present during the interview on August 7, the pilot indicated he placed the fuel valve to the left tank position after he landed at the dock, because fuel tends to flow from one tank to the other while the airplane sits on the water. He believed the fuel selector handle was in the center position ("BOTH") prior to departing Ketchikan on the accident flight. He stated he normally does a "GUMPS" (Gas-Undercarriage-Mixture-Props) check before takeoff.

The company submitted a written statement (attached) to the NTSB IIC on May 10, 1999, stating that after reviewing a draft of this report, the statement in the above paragraph is false. During a telephone interview by the NTSB IIC on April 30, 1999, the company president stated that the pilot was under stress during the August 7 interview, and did not remember saying that he placed the fuel selector to the "LEFT" position while the plane was docked and being refueled.

During an interview with the Alaska State Troopers on August 6, and the NTSB interview on August 7, the pilot stated that the passenger in the back seat must have kicked the fuel selector valve to the "LEFT" position.

Investigation revealed that the fuel selector valve handle was in the "BOTH" position after impact. Fuel was present in the right wing tank, no fuel was present in the left wing tank. The accumulator fuel tank was ruptured, and about one teaspoon of fuel was present in the fuel lines between the accumulator tank and the engine. No rotational damage was observed on the propeller.

INJURIES TO PERSONS

The passenger seated in the right-front seat sustained fatal injuries. The remaining passenger and the pilot sustained serious injuries.

The pilot told the IIC that he did not observe any severe external injuries to the fatally injured passenger. After removing both passengers from the airplane, he attempted to perform cardio-pulmonary resuscitation (CPR) on the fatally injured passenger, but did not obtain any response. He and the surviving passenger indicated that CPR was continued until the pilot was exhausted and could no longer continue.

DAMAGE TO AIRCRAFT

The airplane was destroyed by impact damage.

PERSONNEL INFORMATION

The commercial pilot held single-engine land and seaplane ratings, and an instrument rating. His second class medical certificate was issued on August 11, 1997, with the restriction that he wear corrective lenses. He possessed a Statement of Demonstrated Ability (SODA) and waiver for his eyesight, which was 20/200 correctable to 20/20 with lenses.

The pilot completed initial training with the company in the Cessna 185 on March 27, 1997. He requalified in the Cessna 185 on June 15, 1998. Both of these qualifications were oral tests only. His most recent flight test was his annual 14 CFR Part 135.293 and 135.299 check on June 15, 1998. This flight test was completed in the DHC-2 Beaver.

AIRCRAFT INFORMATION

The seaplane was configured with PK-3000 floats. It was maintained on a 100 hour inspection interval. The most recent inspection was performed on July 29, 33 hours prior to the accident. The engine had accumulated 733 hours since overhaul. A review of aircraft records revealed no recent discrepancies.

The fuel system consisted of two 40 gallon main tanks, with 37 useable gallons per wing, and a 1.5 gallon accumulator tank between the fuel selector valve and the fuel shut off valve. A two speed electric fuel boost pump provides priming and emergency fuel pressure in the event the engine driven fuel boost pump fails. Both the electric and engine driven boost pumps are located forward of the firewall, between the accumulator tank and the engine fuel distributor manifold.

METEOROLOGICAL INFORMATION

The weather at the Ketchikan International Airport at 1453, was winds from 110 degrees at 7 knots; 10 miles visibility; and overcast clouds at 5,000 feet. At 1553, overcast clouds were reported at 7,500 feet.

A photograph taken by the surviving passenger depicts Eddystone Rock, which is located four miles east of the accident site. In this photograph the tops of mountains are visible, and visibility is unobstructed. During an interview on August 7, the pilot stated they flew past Eddystone Rock just prior to the accident.

The pilot described the weather as VFR with high clouds until after the accident. He said weather was not a factor in the accident, but heavy rain after the accident made them cold and uncomfortable.

The pilots of several other airplanes flying in the vicinity were interviewed by the IIC. All of these pilots described areas of rain showers, and a thunderstorm which was located approximately 10 miles northwest of the accident site. They said there was good visibility and ceilings higher than 3,000 feet outside of the rain showers.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest upright, in a muskeg (marshy) area with numerous 50 feet high spruce trees. The wreckage path was oriented on a magnetic heading of 130 degrees, and extended for 300 feet.

Three hundred feet prior to the main wreckage, a 50 feet high tree had a freshly broken top. Light blue and white paint chips were scattered on the ground for the next 60 feet, and then two 7 feet long sections of freshly broken tree tops were found. A section of right wing debris was located 190 feet from the initial tree top. A 20 feet long crater which held the propeller was observed in the muskeg, 220 feet from the initial tree top. Two parallel skid marks, the approximate shape and width of the floats, were located 250 feet from the tree top.

The fuselage, with the cabin intact, tail twisted to the right, and left wing and engine attached, came to rest at an approximate 45 degree nose down angle, 300 feet from the initial damaged tree. Both floats were partially attached, and were on the left side of the fuselage. Both floats had extensive front end damage. The right wing was separated, and located 15 feet beyond the fuselage.

The right wing separated at the wing root, and had a teardrop shaped outward bulge in the area of the fuel tank. The right wing fuel tank remained intact, and contained approximately 15 gallons of blue tinted fuel. The wing came to rest upside down, with the vented fuel caps down. On the ground below the wing, puddles of blue fuel were present in the muskeg.

The left wing remained intact and attached to the airplane. No evidence of any fuel or fluid was found in the left wing tank. The 1.5 gallon accumulator fuel tank was ruptured, and contained no fluid. About one teaspoon of fluid was found in the intact fuel lines to the engine, and the engine fuel filter.

The fuel valve selector handle was found in the "BOTH" position. The valve was determined to be operable, and the internal ports were in the "BOTH" position. The handle was able to be rotated normally, and the position detents were clearly felt when the valve was operated by hand. The selector handle was recessed into its protective housing. The two fuel boost pump split switches were in the "ON," "HIGH," and "LOW" positions. The fuel shutoff valve, located at the firewall, was open.

The trailing edge flaps were attached to the respective wings, and in the retracted position. The flap control handle was in the down, or retracted position.

The propeller spinner was crushed directly aft, and had no rotational scoring or scratching. The three propeller blades were bent aft, and had no chordwise scratches, or leading edge gouges.

MEDICAL AND PATHOLOGICAL INFORMATION

No autopsy was performed on the fatally injured passenger. Due to the emergency medical treatment administered to the pilot, no toxicological samples or drug screenings were performed.

SURVIVAL ASPECTS

All three occupants were wearing seatbelts and shoulder harnesses. Both front seats separated from the seat tracks, but the seat/occupant combinations stayed restrained in place by the belt/shoulder harness assemblies. The surviving passenger told the IIC that the pilot made sure that both passengers had their shoulder harnesses on. The rear passenger seat remained attached to the airplane.

The pilot manually activated the ELT. The pilot attempted to provide shelter from the rain for the surviving passenger using blankets from the airplane's survival kit. He placed orange markers and silver space blankets in open areas around the wreckage, and fired flares when he heard an airplane, which assisted searchers in locating the survivors.

The wreckage was located about 1742 by another company airplane, which was unable to land due to terrain. Two helicopters were dispatched from Ketchikan at 1745, and arrived at the accident site at 1815. Both survivors were transported by helicopter, and arrived at the Ketchikan General Hospital about 1900.

TESTS AND RESEARCH

The engine was removed to the company maintenance facility and inspected by all parties to the investigation on August 8, 1998. No preaccident anomalies were noted.

Inspection of a spare fuel selector valve revealed that as the barrel of the valve is rotated from "BOTH" to "LEFT" there is always an open port which will allow fuel to pass through the valve body. About the 45 degree position, as the fuel ports transit from "BOTH" to "LEFT," the minimum opening cross section exists. Discussions with company check airmen revealed that if the selector handle is placed midway between "BOTH" and "LEFT" while operating at cruise power, the engine will stop from fuel starvation after about six to eight minutes. The check airmen emphasized that this is very sensitive, and only happens about 50% of the time.

The NTSB IIC, the FAA coordinator, and the company representative, each took turns attempting to kick the fuel selector to the "LEFT" position while sitting in the back right seat of a representative Cessna 185. None of the representatives were able to move the valve handle more than one inch (12 degrees) to the left of the "BOTH" position. None could get the valve handle near the 45 degree position, nor all the way to "LEFT." Each representative noted that the valve handle was recessed into the labeling plate, and was protected from the feet of a rear seat passenger.

Each representative noted that the valve handle was sunk deeply between the front seats, regardless of seat position. The valve could not be accessed with the feet of the front seat occupants, either while seated, or while climbing in or out of the airplane.

When questioned during each of three interviews, the surviving passenger stated to the NTSB IIC that she did not place her feet between the seats in front of her. She indicated that she stretched her legs out to the left, behind the pilot, in order to be comfortable.

ADDITIONAL DATA/INFORMATION

The Cessna A185F Floatplane supplement "SECURING AIRPLANE" checklist states: "Fuel Selector Valve should be placed in LEFT TANK or RIGHT TANK to prevent cross-feeding and ensure maximum fuel capacity when refueling."

The Cessna A185F Normal Procedures "BEFORE TAKEOFF" checklist states, in part:

(5) Fuel Shutoff Valve - ON. (6) Fuel Selector valve -BOTH ON. (7) Fuel Quantity Indicators - CHECK QUANTITY.

The Cessna A185F Floatplane supplement "CRUISE PERFORMANCE" chart for 2,000 feet pressure altitude and 11 degrees C, states that at 2,300 rpm and 23 inches of Hg manifold pressure, a brake horsepower of 59%, and a fuel consumption of 12.5 gallons per hour (GPH) will result.

For a flight duration of 45 minutes, this consumption rate results in a consumption of 9.4 gallons, exclusive of additional fuel used during startup, taxi, or climb..

The Cessna A185F Floatplane supplement states: "...cruising climbs should be conducted at approximately 18 GPH up to 4,000 feet... ."

The wreckage was released to the operator on August 7, 1998.

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