Aviation Accident Summaries

Aviation Accident Summary ANC94FA109

BIG LAKE, AK, USA

Aircraft #1

N5198A

CESSNA 172

Analysis

THE PILOT TOLD FLIGHT SERVICE PERSONNEL THAT HE DID NOT KNOW HIS GEOGRAPHIC POSITION DUE TO FOG OBSCURING THE GROUND AND THAT THE FLIGHT HAD FIVE MINUTES OF FUEL REMAINING. THE PILOT SAID THAT HE WAS LOOKING FOR A BREAK IN THE OVERCAST FROM WHICH TO DESCEND THROUGH AND LAND ON THE NEAREST RUNWAY. THE PILOT REPORTED AN AIRSTRIP IN SIGHT AND THAT HE WAS GOING TO ATTEMPT TO LAND ON IT. IN HIS LAST KNOWN COMMUNICATION, THE PILOT SAID THAT THE AIRPLANE WAS STILL UNDER POWER, THAT HE WAS CONSERVING FUEL, AND DESCENDING FAST.

Factual Information

SYNOPTIC On August 16, 1994, at about 1111 Alaska daylight time, a wheel equipped Cessna 172, N5198A, registered to and operated by the pilot-in-command, collided with terrain about 40 feet north of the east end of the Anderson Lake Airstrip. The accident site is approximately 25 nautical miles southwest of Willow, Alaska. The coordinates of the accident site are 61'43".65N X 150'56".62W. The private certificated pilot and one passenger received fatal injuries and the remaining passenger received serious injuries from the accident. The airplane was destroyed by the impact with the terrain and there was no fire. The pleasure flight, conducted under 14 CFR Part 91, last departed the Lake Hood strip in Anchorage, Alaska at approximately 0636 on a round robin cross flight with a refueling stop at the small village of Kakhonak, Alaska. Three five gallon containers of automotive fuel were carried on board the airplane for this purpose. Visual meteorological conditions prevailed in the area of the accident site at the time of the mishap and a VFR flight plan was on file with the Kenai Automated Flight Service Station (AFSS). HISTORY OF FLIGHT On the morning of August 16, 1994, at about 0532, an individual who identified himself as the pilot of N5198A telephoned the Kenai Automated Flight Service Station (AFSS). The pilot requested and was given a standard weather briefing for a VFR round robin flight from Anchorage to the village of Kakhonak via Big River Lakes, Lake Clark Pass, Port Alsworth, and Iliamna, Alaska. At the completion of the briefing, the pilot filed a flight plan. The pilot said that he would call back after 0600 to get an update on the weather. His conversation with the Kenai AFSS ended at about 0543. The pilot next communicated with the Kenai AFSS at 0640:18 when he advised that he had departed the Lake Hood strip and that he wanted to open his flight plan. The flight service station specialist experienced some difficulty in communicating with the pilot. The pilot said that he was using a mobile (hand held) communication transmitter/receiver. At 0643:07 the pilot received and acknowledged the communication by flight service which stated impart, "Iliamna looks IFR - VFR flight not recommended, ah sky partially obscured, estimated ceiling three hundred overcast, visibility one and one half light drizzle fog..fog obscuring eight tenths of the sky, ceiling ragged". At 1038:42 the pilot reestablished communication with the Kenai AFSS. The pilot said that the flight was about 20 miles south of Mt. Susitna, was en route to Anchorage, and "I'm really low on gasoline right here where I'm at". At 1044:18, the pilot said that he did not know his position and that the flight had five minutes of fuel remaining. He reported that the ground fog prevented him from seeing the terrain. At 1048:29, the pilot reported that the flight was in the clear at 8,000 feet, that he could see one group of mountains sticking out of the overcast, and that he was totally lost. At 1050:58, the pilot said that he had been flying for three hours without being able to make radio contact with anyone. The Kenai AFSS personnel plotted a position fix on the aircraft. Beginning at 1051:34, the pilot received and acknowledge a turn to 070 for a heading to Big Lake, Alaska. At 1053:33, the pilot was advised that the flight was about 30 miles west of Big Lake. The pilot responded that the flight would not be able to make Big Lake and that he was looking for a break in the overcast from which to descend through and land on the nearest runway. At 1054:01, the pilot reported that he was over a runway and that he was going to descend and attempt to land on it. At 1054:31, the pilot said that the airplane was still under power, that he was conserving fuel, and that he was descending fast. At the request of Anchorage Air Traffic Approach Control, the flightcrew of an Air Guard HC-130 (King 21) on a local training mission established communication with the pilot of N5198A. The pilot told King 21 that he had an airstrip in sight, that he had five gallons of fuel on board the airplane, that he was going to land and put the fuel in the airplane, and take back off. Shortly thereafter, the emergency locator transmitter (ELT) signal from N5198A was picked up. The record shows that from the time of N5198A's departure from the Lake Hood Airstrip at 0636 until the time of the accident at 1111, a period of four hours and thirty-five minutes transpired. PERSONNEL INFORMATION The pilot, Mr. Stephen A. Anderson, date of birth September 25, 1952, was the holder of Private Pilot Certificate No. 491623744, issued on May 30, 1991, with the rating level of airplane single engine land. His most recent third class medical certificate was issued on May 21, 1993 without limitation. On the questionnaire for the medical certificate, he indicated that his total civilian flight hours was 160. The personal flight log of the pilot was requested from the next of kin. No such records were forthcoming and it is not known if any existed. Federal Aviation Administration (FAA) Airmen Record's indicate that the pilot had no prior accident/incident history or enforcement activity. The cause of death for the pilot was determined by the State of Alaska, Office of the Medical Examiner to be directly related to injuries sustained in the accident. Toxicological testing on tissue samples obtained posthumously from the pilot were negative for alcohol, major drugs of abuse, and prescription and over the counter medication. PERSONNEL/WITNESS INFORMATION Telephone Interview - Mr. Ron Anderson The pilots brother, Mr. Ron Anderson, told the NTSB IIC that at the time of the accident his brothers total flight time was roughly 200 hours, that he had flown about 20 hours in 1994, and 8 hours during the previous 30 days. Most of the flight time was accrued in N5198A. Mr. Anderson said that the fuel capacity of N5198A was 42 gallons and that his brother topped off the plane's fuel tanks the night before the flight. Mr. Anderson said that he was a pilot, that he had flown N5198A on numerous occasions, and that he was familiar with the fuel burn and fuel endurance of the airplane. He said that the plane's fuel quantity gauges were very accurate, that in cruise flight the airplane burned between 7 and 8 gallons per hour, and that with full fuel tanks, the plane's flight endurance was approximately 4 hours and 30 minutes. AIRCRAFT INFORMATION The airplane was a 1956 model Cessna 172, serial number 28198. The plane was registered to Stephen Anderson on June 12, 1989. The maintenance records on the airplane show that it averaged about 50 hours of flight time annually during the previous two years. The plane was last annualed on May 20, 1994. As of that date, the airframe had accrued 4758 hours, and the engine 1393 hours since rebuild. The plane was powered by a Teledyne Continental O-200, SN:7390D-2-2. An aviation mechanic who worked on the airplane said that he was not aware that the airplane had an STC for automotive fuel. METEOROLOGICAL INFORMATION The nearest weather reporting facility to the accident site was in Willow, Alaska (identifier Z22), located about 8 nautical miles to the west. The 1045 Record Observation was 5000 feet scattered, 20,000 thin broken, visibility 70 statute miles, temperature 62 degrees fahrenheit (F), dew point 54 F, wind from 200 degrees true at 9 knots, altimeter 30.19. WRECKAGE AND IMPACT INFORMATION FOREWORD Alaska State Police personnel were the first authorities to arrive at the scene on the afternoon of August 16, 1994. Their observations were that the pilot was not wearing his seat belt at the time of the mishap because the belt was found latched across the back of the seat. The NTSB IIC conducted the on scene investigation on August 17, 1994. Federal Aviation Administration (FAA) IIC, Ms. Ann Graham, assisted in the this effort. The airplane was found inverted in a grassy area about 40 feet north of the east end of the east/west Alexander Lake Airstrip. The surface of the ground was soft. The longitudinal axis of the airplane was aligned on a magnetic heading of 175 degrees. The crash site was adjacent to a small outcropping of brush approximately 20 feet in height. The runway was just beyond the brush. There were no visible signs of recent damage to the nearby vegetation and trees. There were no indications that the airplane moved and/or recoiled from the initial impact point. STRUCTURE The structure of the airplane remained intact. Continuity was established with the flight control system up to the cockpit interior. The gross deformation of the cockpit environment in the area of the flight controls resulted in slack control cables. The flight control cables that were able to be viewed did not display any signs of wear. Both halves of the propeller were symmetric. The leading edge and chord were smooth. Both halves were bent rearward 15 to 20 degrees. The nose of the airplane was crushed rearward. The engine remained intact. The force of the impact moved the engine rearward and downward against the firewall forcing the firewall into the back of the instrument panel. The gascolator was broken off and the glass bowl was broken. There was no fuel evident in the fuel line to the carburetor. The fuselage was buckled just aft of the baggage compartment. The deformation was more extensive along the left top and side of the fuselage. The lower structure of the vertical stabilizer and rudder were rippled. The horizontal stabilizer and elevator did not show any physical signs of damage. The leading edge of both wings from the support strut attachment outboard were crushed inward. The flaps were retracted. Both fuel tanks were examined and their fuel caps were removed. There was no visible sign of fuel in either tank, nor an odor of fuel present at the accident site. COCKPIT The fuel selector valve handle was selected to the right wing fuel tank. The selector assembly did not appear to be damaged. There was positive detente in each of the selector cam positions.

Probable Cause and Findings

THE PILOT'S FAILURE TO MAINTAIN AIRSPEED. FACTORS IN THE ACCIDENT WERE THE FOG, AND THE PILOT BECOMING LOST/DISORIENTED.

 

Source: NTSB Aviation Accident Database

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