Aviation Accident Summaries

Aviation Accident Summary SEA97LA192

LYNNWOOD, WA, USA

Aircraft #1

N7533M

Cessna 175

Analysis

The pilot stated that he checked the fuel tanks prior to taking off from a private airstrip, and that he observed 6.5 gal. in one tank, and 8.5 gal. in the other tank. He also stated that he was concerned about the fuel quantity, so he decided to fly to an airport that had fuel facilities. During the initial climb after the takeoff, the engine began to run rough. The pilot ditched the airplane in a lake. He stated that the fuel tank pick-up ports may have unported during the 'steep' climb. During the initial pilot interview after the event was upgraded from an incident to an accident, the pilot stated that he had destroyed all evidence that would be required to determine if fuel exhaustion or engine malfunction had occurred, and he did not provide requested information about refueling receipts. Examination of the pilot's logbooks revealed that the pilot had logged 5.1 hours of flight time in the accident airplane during the 4 flights previous to the accident flight. The log did not contain any reference to refueling or of any destination airports that have refueling facilities. Calculations revealed that the airplane would have consumed more than its 43 gallons of useable fuel during the 4 previous flights.

Factual Information

On August 17, 1997, about 1030 Pacific daylight time, N7533M, a Cessna 175, operated by the owner/pilot, was ditched in a lake following a loss of engine power during takeoff near Lynnwood, Washington. The airplane was substantially damaged. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight departed from Lynnwood and was en route to Everett, Washington. The flight was conducted under 14 CFR 91. In a telephone interview with the pilot, and in a written statement sent to the Safety Board (attached), the pilot stated that he checked the quantity of fuel in both wing fuel tanks prior to takeoff from a private airstrip near Lynnwood, known as Martha Lake. He stated that he "dipped" the tanks and noticed that he had 6.5 gallons in one tank, and 8.5 gallons in the other tank. The pilot further stated that he was concerned about the fuel quantity and decided to fly to Paine Field near Everett, Washington, to refuel the airplane, since fuel was not available at the Martha Lake airstrip. The pilot stated that he performed a preflight inspection of the airplane, boarded the passenger, started the engine, ran the engine up with no discrepancies noted, taxied for takeoff, lowered 20 degrees of flaps for "best climb," applied full power, and began the takeoff. During the initial climbout, the engine began to run rough and "died." The pilot stated that he attempted to restart the engine by checking the fuel selector, fuel mixture control, master switch, and ignition switch. He then elected to ditch the airplane in Martha Lake after efforts to restart the engine had failed. The airplane was substantially damaged during the ditching. The pilot's wife, who was a passenger in the airplane, corroborated the pilot's statements. A ground witness (statement attached) stated that he "... heard what sounded like a motorboat motor reving and dying about 3 or 4 times then silence...." just before he saw the airplane ditch about 80 feet in front of him. The pilot further stated that the fuel tank pick-up ports may have unported during the initial climbout because the attitude of the airplane during the climbout was "steep." When asked when the pilot last refueled the airplane, he replied that he was not sure. A Federal Aviation Administration (FAA) aviation safety inspector from Renton, Washington, responded to the accident. He stated that the airplane was partially submerged in water and that he did not observe any substantial damage. He stated that the event was probably an incident and he allowed the pilot to remove the airplane. The pilot then moved the airplane out of the lake, drained the fuel tanks and partially disassembled the engine. Another FAA inspector later examined the airplane and stated that there was evidence of substantial damage to the airframe. At this point, the event was classified as an accident. During the initial interview with the pilot by the Safety Board after the event was reclassified as an accident, the pilot stated that he had destroyed any and all evidence that would be required to determine if fuel exhaustion or engine malfunction had occurred. On August 20, 1997, the pilot was sent a request to complete a Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2 (copy of NTSB letter attached), and was also asked to provide a copy of the last fueling slip, receipt or other record detailing the amount and type of fuel loaded on the aircraft prior to the accident. He was also asked to submit copies of pages from his personal logbook which contained the last 90 days prior to the accident, and he was asked to return the completed form and requested materials within ten days as per federal regulations. The form was sent to the pilot's current mailing address on file with the FAA. No response was received from the pilot, despite numerous telephone messages left on the pilot's telephone answering machine. The pilot then informed the Safety Board that his address had changed. On October 17, 1997, the pilot was sent another request to complete a Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2 (copy of NTSB letter attached), and he was also asked to provide the fueling and logbook information. The pilot sent back a partially completed NTSB Form 6120.1/2 (attached), excerpted copies from his personal logbook that were partially unreadable (attached), and no records to document the last refueling prior to the accident. On March 2, 1998, the pilot was sent another request to provide the personal logbook and refueling information (copy of NTSB letter attached). The pilot signed the return receipt for the letter on March 10, 1998 (copy of returned receipt attached), and did not provide the requested information. The Safety Board examined the partially unreadable excerpts of the pilot's personal logbook. The last six flights were documented as follows: August 13 - From "HOME" to "1SO" - 2.1 hours total duration of flight August 13 - From "HOME" to "Ranger Crick" - 2.7 hours total duration of flight August 15 - From "HOME" to "HOME" - 0.8 hours total duration of flight - Remarks: "t & GO PRA" August 16 - From "HOME" to "HOME" - 1.2 hours total duration of flight August 17 - From "HOME" to "MARTHA LAKE AIR P." - 0.4 hours total duration of flight August 17 - Accident Flight The pilot's home was near a private grass airstrip near Carnation, Washington. There are no fuel facilities available on the airstrip. There are also no fuel facilities available at the Martha Lake Airstrip. The airport identifier for the Pierce County Airport in Puyallup, Washington, is "1SO;" there are fuel facilities available at this airport. No public airport could be found by the name of "Ranger Crick" or "Ranger Creek." The examination of the logbooks revealed that the pilot had logged 5.1 hours of flight time in the accident airplane during the four flights previous to the accident flight. The information logged in the four flights did not contain any reference to refueling or any identifiers of destination airports that have refueling facilities available. According to the 1959 Cessna 175 Owner's Manual (excerpt's attached), fuel is supplied to the engine from two 26-gallon aluminum tanks, one in each wing, of which 21.5 gallons in each tank are useable in all flight conditions. Data found in the performance information indicate that the airplane consumes between 6.3 and 10.6 gallons per hour, depending on propeller RPM setting, with a "lean mixture" in cruise flight under standard atmospheric conditions, maximum gross weight, and at an altitude of 2,500 feet above mean sea level (msl). The data also indicate that each takeoff, including warm-up and taxi, consumes 1.2 gallons at sea level conditions, 59 degrees F, full throttle, flaps up, and best rate-of-climb speed. Using this data, the Safety Board calculated that the airplane would have consumed more than its 43 gallons of useable fuel if it were flown for six takeoffs and a cumulative 5.1 hours of cruise flight at 2,600 RPM, 2,500 feet msl, maximum gross weight, and a leaned mixture.

Probable Cause and Findings

The pilot's inadequate preflight planning and preparation, which led to fuel exhaustion and subsequent loss of engine power.

 

Source: NTSB Aviation Accident Database

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