Aviation Accident Summaries

Aviation Accident Summary SEA08LA012

San Carlos, CA, USA

Aircraft #1

N5050B

Beech F35

Analysis

After leveling off at 1,000 feet over a salt water bay for the short repositioning flight, the engine lost power. Attempts by the pilot to restart the engine proved unsuccessful, prompting him to ditch the airplane in the salt water bay. The airplane was recovered from the salt water environment about 24 hours after the ditching. The engine subsequently underwent two examinations, the first of which resulted in the engine running for a period of 5 seconds before losing power. A second later attempted test run was unsuccessful due to the effects of the extensive degree of salt water contamination and corrosion. A visual inspection of the engine failed to reveal any anomalies that would have precluded normal operation. The airplane had just come out of its most recent annual inspection the day prior to the accident, and maintenance records indicated the engine had accumulated 60.20 hours since its most recent overhaul. The pilot reported that prior to takeoff the fuel selector was positioned on the left main tank, and that 60 to 65 gallons of fuel was on board.

Factual Information

On October 27, 2007, approximately 1030 Pacific daylight time, N5050B, a Beech F35, sustained substantial damage after the pilot ditched the airplane into the San Francisco Bay, about 1 mile north of the San Carlos Airport (SQL), San Carlos, California, following a loss of engine power during cruise flight. The certificated private pilot and his sole passenger were not injured. Visual meteorological conditions prevailed at the time of the accident, and a flight plan was not filed for the local flight, which was operated in accordance with 14 Code of Federal Regulations (CFR) Part 91. The flight departed SQL about 1020, with its destination being the Hayward Airport (HWD), Hayward, California. In a written statement provided to the NTSB investigator-in-charge (IIC), the pilot reported that after taking off and reaching 500 feet he made a right turn and continued to climb to 1,000 feet. The pilot stated that after leveling off at 1,000 feet he pulled the power back to 23 inches and 2,300 rpm respectively, leaving the cowl flaps and mixture alone, as this would be a short flight. The pilot reported that after listening to the HWD Automated Transcribed Information Service (ATIS), "...the engine abruptly cut-out." The pilot stated that he then immediately turned on the electric fuel pump and looked directly at the fuel pressure [gage]; nothing seemed out of order. The pilot revealed that he then turned the fuel pump off and switched from the left main fuel tank to the auxiliary tanks and turned the fuel pump on again, but the engine did not respond. The pilot reported that he then set up for max glide, "...and I also made a slow right turn back towards dry land in case I was going to have to ditch." The pilot further reported that he then switched tanks again to the right main and then back to the left main with the fuel pump on, while checking the magnetos and circuit breakers. "Nothing seemed to be amiss except that I had a dead engine. The one thing that boggled my mind was that the fuel pressure was reading as if normal." The pilot reported that he set up for the ditching with the gear confirmed up and the flaps fully retracted, then called SQL informing the controller of the engine failure and that he was going to have to ditch. The pilot subsequently made a successful ditching, exited the airplane with his sole passenger, and swam to shore. A review of the airplane's maintenance records revealed that the most recent annual inspection was completed on October 27, 2007, with a total time on the airframe and engine of 3,306.9 hours. The engine had accumulated a total of 60.20 hours since its most recent major overhaul. The pilot reported that he had flown the airplane for about 1 hour the day it came out of the inspection, with no anomalies noted. The pilot stated that prior to the accident flight he "...walked through every step of the preflight, including draining of the fuel taps and visual inspection of the oil, fuel tanks and external airframe." The pilot reported that at the time of takeoff he had 60 to 65 gallons of fuel on board. The airplane was subsequently recovered from the salt water environment the following day and transported to a secure facility for further examination. The recovery firm indicated that while none of the fuel tanks were breached, some leaking did take place. The recovery team reported about 20 to 21 gallons of fuel was drained from the airplane after recovery from the bay, with the break down per tank as follows: left hand wing tip tank: 0 gallons left hand wing aux tank: 9 gallons left hand wing main tank: 0 gallons right hand wing main tank: 3 gallons right hand wing aux tank: 8 gallons right hand wing tip tank: 1.5 gallons On December 12, 2007, under the supervision of a Federal Aviation Administration airworthiness inspector, a representative of the engine manufacturer examined the engine. During the examination, and in preparation prior to conducting engine run, the engine representative reported that the carburetor fuel screen, all spark plugs, all six cylinders, and both magnetos all exhibited debris consistent with salt water emersion. The top spark plugs were reinstalled in the engine, while the left and right magnetos were replaced with the same make and model. An external fuel supply and electric fuel pump were connected to the engine. The engine was successfully started and ran for about 5 seconds before quitting. After the engine quit, oil was observed draining from an opening at the bottom of the crankcase. The engine was subsequently sent to the Teledyne Continental Motors Analytical Department, Mobile, Alabama, for further examination. On February 5, 2008, under the supervision of an NTSB air safety investigator, the engine was further examined at the facilities of Teledyne Continental Motors, Mobile, Alabama. The examination failed to reveal any anomalies that would have prevented normal operation and production of rated horsepower. It was also reported the engine could not be test run, given the amount of salt water contamination.

Probable Cause and Findings

A total loss of engine power for undetermined reasons. Contributing to the accident was the lack of suitable terrain for a forced landing.

 

Source: NTSB Aviation Accident Database

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