MIA99LA061
MIA99LA061

On December 31, 1998, about 1712 eastern standard time, a Cessna 177, N29451, registered to a private individual, collided with a bridge then the ground during a forced landing near Fort Lauderdale, Florida. Visual meteorological conditions prevailed at the time and a VFR flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the private-rated pilot and one passenger were not injured. The flight originated about 1425, from the Exuma International Airport, Exuma Island, Bahamas.

The pilot stated that on December 23, 1998, the flight originally departed an airport in Delaware and flew 3 legs to Boca Raton, Florida; the fuel tanks were reportedly filled after all 3 legs and the total fuel purchased was documented to be 54.3 gallons. The average fuel consumption for the 2nd and 3rd flights was calculated to be the 11.08 gallons per hour (gph), but the pilot reported that the historical fuel consumption was 8.6 gallons per hour. The pilot stated that he while examining the airplane on December 26, he noted a "barely noticeable" blue stain on the aft ride side only of the nose landing gear wheel pant; the airplane had not been flown since landing in Boca Raton on December 23, 1998. He attributed the stain on the wheel pant based on appearance, feel, and smell, to be dirty engine oil associated with a previous oil change. He also stated that the airplane was equipped with "long filler necks" and the difference in the fuel quantity in the tank when the fuel level is at the top versus the bottom of the filler neck is 4-5 gallons. On December 26th, he performed a preflight to the airplane but because a ladder was not available, he did not visually look into each tank to verify the fuel level. He reported that he did; however, while standing on the ground, place his finger into each fuel tank and verified that his finger was wet. On that date he received a receipt showing the amount of fuel added which correlated to what he thought was the amount expected. No maintenance was performed to the airplane while at that location. The airplane was flown on December 28, 1998, on two flights and after landing following the second flight, the pilot noted fuel dripping onto the nose landing gear wheel pant. He elected to pull the fuel shutoff valve which stopped the fuel leak.

On December 29th, he removed both engine cowlings then deactivated the fuel shutoff valve and turned on the auxiliary fuel boost pump. Fuel leakage from the carburetor was noted, which did not stop when the pump was turned off or when the mixture control was placed to the idle cutoff position. The pilot stated that the fuel leakage appeared to be coming from the main fuel nozzle of the carburetor. He reactivated the fuel shutoff valve and reinstalled the engine cowling; estimating that less than 1 cup of fuel was lost during the check. He then used a uncalibrated "universal" fuel dipstick and based on the reading, flight time, historical fuel consumption, and the amount indicated by the fuel gauges, determined no significant fuel loss occurred. The fuel quantity found was as expected.

On December 31st, the pilot flew to the Exuma International Airport, and after landing, the total flight time from his departure from the U.S. to that point was 3.1 hours based on the tachometer. A total of 14 gallons of fuel were added for the planned 2.5-hour flight using the average historical fuel consumption of 8.6 gallons per hour. No maintenance was performed there. The pilot also stated that based on the cost of fuel and for a safety factor for flying over water, he elected not to fill the fuel tanks. The flight departed with the knowledge that the Fort Lauderdale Executive Airport U.S. Customs office closed at 1700 hours and while climbing to about 7,000 feet, over Staniel Cay, the pilot filed a VFR flight plan while airborne. The flight climbed to 8,500 feet and flew direct to Nassau, where the flight climbed to 10,500 feet and flew direct to Bimini, then flew direct to the Fort Lauderdale Executive Airport, Fort Lauderdale, Florida. The flight entered the traffic pattern about 6 minutes after the advertised closure time of Customs, and at that time the fuel gauges indicated just below 1/4, which was lower than expected; they then began to decrease rapidly. The flight turned onto final approach when the pilot was notified by the controller that customs was closed. The flight then proceeded towards the Fort Lauderdale International Airport and was cleared to land on runway 13. While flying at 1,200 feet, on a 2-mile final, the engine quit, but the propeller continued to windmill; he noted that the fuel pressure was zero. He verified that the fuel selector and the magneto switch were in the "both" position but did not change them. He applied carburetor heat but this did not restore engine power. With heavy traffic on the nearby north-south and east-west expressways, he maneuvered the airplane for a forced landing on the westbound lanes of a road. While descending, the left main landing gear collided with a portion of a bridge which caused separation of the gear. The airplane then touched down and veered to the left into a guardrail. The airplane was recovered without removing the wings, and was transported to a nearby airport.

The airplane was inspected by an FAA airworthiness inspector 4 days after the accident, and the fuel tanks were drained and found to contain about 4 ounces of fuel. Drops of fuel were found in the flexible fuel line from the gascolator to the carburetor and about 1/2 ounce of fuel was drained from the carburetor bowl. The battery master was turned on and the fuel gauges were found to indicate empty. The carburetor was retained for further examination.

A fuel log that dates to June 9, 1995, was provided by the pilot which documents flights by date, location, tachometer time, and whether the fuel tanks were full. Review of the log for only those flights that were documented to depart with full fuel tanks and have the tanks filled after landing was accomplished. A total of 24 flights that met those conditions were noted which revealed that the average total fuel consumption for the flights was 8.9 gallons per hour (gph). The highest calculated fuel consumption for any of the flights was 11.56 gph for a single flight lasting 2.5 hours.

The airplane was equipped with a 180-horsepower engine that was installed in accordance with a Supplemental Type Certificate.

Initial examination of the carburetor revealed that the mixture control shaft was loose in the housing. The carburetor was bench tested as received, which revealed uncontrolled fuel flows at the first two test points which are associated with low throttle settings, the recorded fuel flows were greater than the established fuel flow limits. The next test point revealed that the fuel flow was less than the established limit, and the final test point revealed that the fuel flow was less than the established limit. The carburetor was removed from the test bench and examined which revealed blue colored torque stripe material on several of the throttle body to bowl screws. Movement of the throttle arm by hand revealed that full throttle travel was not possible due to the adjustment of the jet-air metering pin which was determined to be positioned flush plus 2.50 turns where the specification is flush plus 1.250 turns. Examination of the mixture control assembly revealed missing and incorrectly installed hardware. Severe wear was noted at both ends of the mixture control metering valve assembly, on the sleeve, and on the washer-horseshoe (mixture control valve head). Examination of the float revealed that one side of the hinge float was worn through to failure and the other side was severely worn. Also, the accelerator pump discharge check valve was noted to be severely worn, and corrosion pits and black residue was noted in the bottom of the carburetor bowl. A lead seal was noted to be imprinted with the letter "N". A copy of the report is an attachment to this report. According to personnel from Precision Airmotive Corporation, the condition of the mixture control shaft would result in an increase in fuel flow at the full rich position; however, the excess fuel flow could be adjusted using the mixture control.

The carburetor received a final production flow test following manufacture on October 20, 1966, and was shipped to Lycoming, where it was installed on the accident engine by engine serial number. Review of the maintenance records revealed that the carburetor was overhauled on January 26, 1993, by a FAA certified repair station, and installed on the overhauled engine on January 27, 1993. The overhaul was performed by Navajo Accessories, Inc. According to personnel from that facility, they use a letter "N" to imprint lead seals and probably used blue torque stripe material during the time when the carburetor was overhauled. The records for the overhaul that was performed in 1993, were not available from the facility that performed the carburetor overhaul; FAA requires facilities to only keep records for 2 years. The overhauled carburetor was determined to have accumulated 544 hours since installation following overhaul 5 years and 11 months earlier. There was no record of the carburetor being repaired or overhauled since the last overhaul in 1993.

Review of the NTSB Pilot/Operator Aircraft Accident Report Form submitted to and signed by the pilot revealed that in the recommendations section of the report he wrote in part, to recognize clues that carburetor required service and may have leaked fuel. The pilot further stated that on two occasions in November 1998, the engine continued to run erratically after placing the mixture control to the idle-cutoff position, that this had not occurred previously. He attributed this to contaminant at the primer which allowed fuel to be introduced into the intake manifold. The pilot did not have the carburetor examined after the two occurrences. He stated that he intended on changing the primer pump O-rings if the engine continued to run erratic after placing the mixture control to the idle-cutoff position again. According to FAA records, the pilot is not a certificated airframe or powerplant mechanic.

The airplane minus the retained carburetor was released to Mr. R.M. Barrett, on January 13, 1999. The retained carburetor was released to Mr. Joel A. Frana, on March 18, 1999. Mr. Frana purchased the wreckage from the insurance company.

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