Aviation Accident Summaries

Aviation Accident Summary ERA11LA417

Sagaponack, NY, USA

Aircraft #1

N2ER

RYAN AERONAUTICAL ST3KR

Analysis

The pilot stated that he conducted a thorough preflight inspection of the two-place tandem-seat airplane, and determined that there were 12 gallons of fuel onboard for the intended 30-minute flight, which he calculated should have consumed 4 gallons of fuel. After checking the fuel quantity, the pilot initially had the passenger order fuel but subsequently decided to forego the order once he determined its arrival would be delayed. The passenger confirmed that the fuel quantity sight gauge, located on top of the fuel tank forward of the front windshield, indicated a fuel level between the 10- and 15-gallon marks. After an uneventful engine runup, the pilot, flying from the rear seat, attempted a takeoff. However, after adding power, the engine began to run roughly, and the pilot aborted the takeoff. The pilot performed another engine runup and then took off with no additional anomalies noted. About 25 minutes after engine start, the pilot made an approach to a private airstrip for landing but then opted to go around. During the go-around, witnesses heard the engine lose power, regain it, and lose power again. The pilot checked that the fuel selector was in the "Reserve" position, the magnetos were on, and the carburetor heat was off. The airplane then descended into a corn field and nosed over after landing, coming to rest inverted. Postaccident examination of the airplane revealed no preexisting mechanical anomalies and no fuel in the fuel tank; however, the fuel sight gauge on top of the fuel tank was broken, and likely allowed any remaining fuel to drain out of the tank when the airplane was upside down. Before-landing procedures called for the fuel selector to be moved from the "Main On" position to the "Reserve" position, which would have allowed the bottom 3 gallons of the 24-gallon fuel tank to flow to the engine. However, the fuel selector valve was found in the "Main On" position, and damaged wreckage surrounding it confirmed that it was in that position upon ground impact. Pilot operating manual fuel consumption rates indicate scenarios where the available 9 gallons could have been consumed during the flight. However, exact consumption rates for the profile flown could not be determined, and the passenger, who was sitting in the front seat, stated that he saw between 5 gallons and 10 gallons of fuel indicated on the sight gauge when engine power was lost. Engine anomalies occurred twice after the pilot added power: during the initial takeoff attempt, and again during the go-around attempt. With an outside air temperature of about 84 degrees F and a dew point of about 75 degrees F, the probability of carburetor icing at glide and cruise power existed. However, it is not known what effect the addition of carburetor heat might have had on the loss of engine power during the go-around attempt.

Factual Information

On July 24, 2011, at 1013 eastern daylight time, a Ryan Aeronautical ST3KR, N2ER, was substantially damaged during a forced landing in Sagaponack, New York. The certificated airline transport pilot and the passenger were seriously injured. Visual meteorological conditions prevailed. No flight plan had been filed for the local flight, between East Hampton Airport (HTO), East Hampton, New York, and a private airstrip on Foster Farm, in Sagaponack. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to several witnesses, the airplane made a low approach over the farm airstrip, after which, the pilot added power then made a left turn. One witness also noted that during the climb, the engine "coughed, then ran fine again." Another witness stated that as the airplane climbed, the engine didn't appear to be making full power, then it went to full power momentarily before losing power. A third witness stated that the engine would "go on and off…then stopped making noise." A fourth witness heard the engine "cutting out and then start up again." The airplane subsequently descended into a corn field. In a written statement, the pilot noted that he had taken off intending to fly for 30 minutes. During the flight, he flew over Foster's Farm and decided to land. He set up for a landing, then decided to go around. The pilot then turned a left crosswind, then downwind, and began experiencing an engine problem at 200 to 300 feet. He immediately turned the airplane toward the runway, checking airspeed, magnetos and carburetor heat. With no improvement in engine performance, the pilot elected to land in a corn field adjacent to the airstrip. According to a Federal Aviation Administration (FAA) inspector, the airplane cut an approximately 25-foot swath through standing corn before coming to rest inverted. An examination of the propeller revealed that the two wooden blades had fractured in an aft direction. The Kinner R56-series radial engine was intact, with no obvious fuel leakage. The fuel tank, which was just behind the firewall, was slightly collapsed, but with no fuel leakage evident. The fuel cap was on and tight, also with no leakage evident. The airplane was subsequently moved, while suspended still upside down, to an open access area. There, the fuel cap was removed and 6 to 8 ounces of fuel were recovered from the fuel tank in a clean white pail. The soil that had been beneath the forward part of the wreckage contained a 6-inch diameter area, scooped to a "minimal" depth, with an odor of aviation fuel. The fuel filter bowl lower feed line fitting was removed, and less than 1 ounce of fuel was drained, while no fuel was found at the three-way selector valve. Both, the front cockpit and rear cockpit fuel selector valve handles, which were mechanically connected, were in the "MAIN ON" position, with the front handle having paint transfers and scrapings consistent with it being in that position at the time of the accident. Photographs of both fuel selector valve handles also showed them to be in the MAIN ON position, with the front handle jammed into its position by aft-displaced wreckage. The two other handle positions were "RES. ON" and "BOTH OFF." As found, the front handle could not have been moved from the RES. ON position to the MAIN ON position during ground impact. Fuel selector valve placards also stated, "CAPACITY MAIN 21 GAL, RES. 3 GAL" and, "ALWAYS TAKE OFF AND LAND WITH FUEL FEEDING FROM RESERVE." A fuel system diagram revealed that within the interior of the fuel tank there was a main fuel line finger strainer that allowed fuel to flow to the three-way selector valve. Positioned lower in the tank, was a reserve line finger strainer that also allowed fuel to flow to the three-way selector valve via a separate fuel line. In an interview summary with FAA inspectors, the pilot indicated that he had conducted a thorough preflight inspection of the airplane and had ordered fuel from the local fixed base operator. Fuel was not available, so he decided to depart with what he determined was 12 gallons of fuel by looking into the fuel tank with a flashlight. One of the FAA inspectors also noted that, according to the ramp attendant, the pilot requested fuel about 0900, and the passenger came by about 0930 to inquire what the delay was. The attendant replied that he was the only one on duty to refuel aircraft and that it would be another 15 to 20 minutes before he could refuel the airplane. In an interview summary with FAA inspectors, the passenger stated that the pilot did not choose to wait for the fuel truck, and indicated that the fuel tank was about half full. The passenger also stated that the pilot performed at least two engine run-ups and attempted two takeoffs prior to departing the airport. A police officer stated that, about 0945, he had seen the airplane make two high-speed mid-field taxis from east to west, then taxi back to mid-field for a takeoff in a westerly direction. An FAA review of fuel purchases revealed that the pilot had last filled the fuel tank on July 11, 2011, then flew from Sullivan County International Airport (MSV), Monticello, New York, to HTO. Straight line distance was about 120 nautical miles, with an estimated time en route of about 1.5 hours. According to the airplane's Pilot's Flight Operating Instructions (PFOI) "allow 3.5 gallons for warm-up, take-off, [and] a climb to 3,000 feet altitude." The Instructions also noted that takeoff power at sea level and a full rich mixture utilized 17.0 gallons per hour, economical maximum power at a full rich mixture utilized 9.3 gallons per hour, and minimum specific power at a "best setting" mixture utilized 8.0 gallons per hour. The pilot indicated that he used 10 gallons per hour for planning purposes. Specific altitudes flown could not be determined, although photographs taken by the passenger appeared to be taken from altitudes between 1,000 and 2,000 feet. The information above was published on October 25, 2011. After reading the factual report, the pilot contacted the NTSB and provided additional information. - The pilot noted that there had been no mention of the fuel tank capacity sight gage when describing the wreckage. The PFOI and a photograph provided by the pilot revealed that the sight gauge was a glass cylinder attached to the top of the fuel tank, in front of the windshield. The gauge, which was labeled in 5-gallon increments from "E" to "24" had been broken off in the accident, which, according to the pilot, would have allowed drainage of remaining fuel from the fuel tank when the airplane was upside down. The pilot also noted that because the fuel tank cap was vented, it would have provided another means by which remaining fuel could have drained from the tank after the airplane nosed over. - The pilot stated that the airplane had 12 gallons of fuel onboard at engine start, and that 4 gallons were burned, which should have resulted in 8 gallons remaining in the fuel tank at the time of the accident. - The pilot clarified that after engine run-up, and as he was attempting to take off from runway 28, he aborted the attempt due to the engine "running rough after full power was applied," which the pilot had never before experienced in the airplane. The pilot cleared the runway, performed another engine run-up with no anomalies noted, and took off. About 20 to 25 minutes later, when the pilot added power for the go-around, the engine developed the same symptoms as during the first takeoff attempt. - The pilot stated that after the loss of engine power, he "checked the fuel selector in the reserve position, carb heat off, mags on, and air speed." The passenger wrote an additional statement on March 17, 2012, which was provided to the NTSB on May 16, 2012. In it, the passenger noted that he observed the fuel sight gauge during the preflight inspection, and that it indicated fuel quantity to be between the 10- and the 15-gallon marks. [Once the passenger was seated, the fuel sight gauge would have been sticking up in front of him, as he was sitting in the front seat of the two-place tandem-seat airplane.] After an uneventful start, there was a 3- to 5-minute taxi to the runway. The pilot then attempted a takeoff, but noticed that the engine was "running rough," so he powered it down. A second takeoff attempt was successful without any issues noted. The passenger also reported that engine start occurred about 0945, takeoff about 0950, and about 1010, the engine began to malfunction. Given the pilot's earlier inquires about fuel, the passenger's first thought was to look at the fuel sight gauge, which indicated a fuel level between the 5- and 10-gallon marks. The wreckage was subsequently sold and multiple attempts to reach the new owner at the contact telephone number provided by the pilot were unsuccessful. Weather observations at HTO, at 0857, included a temperature of 29 degrees C (84 degrees F) and dew point 23 degrees C (73 degrees F), and at 1053 (there was no intervening recorded data), a temperature of 29 degrees C and dew point of 24 degrees C (75 degrees F). Comparing those temperatures and dew points on an FAA carburetor icing probability chart indicated the probability of carburetor icing at glide and cruise power.

Probable Cause and Findings

The loss of engine power for undetermined reasons.

 

Source: NTSB Aviation Accident Database

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