ERA14LA362

A total loss of engine power for reasons that could not be determined because postaccident examination of the engine revealed no mechanical malfunctions or failures that would have precluded normal operation. Contributing to the accident was the pilot’s failure to identify occupants on the ground near the shoreline in the airplane’s forced landing path.

The private pilot was conducting a short flight from one airport to another airport to obtain fuel for the airplane. The pilot reported that the airplane had been kept in a hangar and had not been flown in the preceding 3 1/2 months. The pilot performed a preflight inspection of the airplane and noted the fuel quantity but he did not sump the fuel tanks. He subsequently performed an engine run-up and departed without incident. He climbed the airplane to about 1,000 ft and, after some maneuvering, eventually flew over the water and paralleled a shoreline toward another airport. The pilot reported that the engine then began to run roughly and that he heard a "missing, knocking, hitting sound" but that neither he nor the pilot-rated passenger noted a decrease in engine rpm. Although the pilot rotated the ignition switch through the various positions and changed fuel tanks, the engine lost power and the propeller began wind-milling. The pilot declared an emergency and angled the descending airplane toward the shoreline. He was concerned that, if he landed in deeper water, the fixed-landing-gear airplane would flip over. The pilot saw a group of people along the beach and attempted to navigate around them. He then aimed for a spot where he thought there were no people, and the airplane touched down in the water near the shoreline and then came to rest on the sand near the water's edge. The pilot exited the airplane and learned that he had struck two people in the water. Postaccident examination of the airframe and engine, which included a successful engine test run using fuel from the airplane's fuel system, did not reveal any evidence of water contamination or mechanical malfunctions or failures that would have precluded normal operation. Given this evidence, the loss of engine power was likely a transient condition. Although the condition could have resulted from pilot action, neither the pilot nor the passenger indicated that the pilot took any action that would have resulted in the loss of engine power. Although the airplane was operating in conditions that were conducive to the formation of carburetor ice without the carburetor heat on, the fixed-pitch propeller/engine combination did not gradually lose rpm, which would have occurred if carburetor ice had developed. Therefore, the reason for the loss of engine power could not be determined. The National Transportation Safety Board asked the Federal Aviation Administration (FAA) to provide information on any policy that addressed protecting people on the ground during a loss of engine power. The FAA responded, in part, "Because of the variety of possible emergency situations, it is impractical to apply a specific policy addressing risks involved between beach landings and ditching. The FAA relies on its requirements for pilot training on aeronautical decision making to compel pilots to pursue courses of action in an emergency which appear to be the safest and most appropriate under the circumstances." Once the engine failed, the pilot chose to land on a shoreline area that he incorrectly believed was unoccupied.

Water in Fuel Per FAA Advisory Circular 20-125, "Water can enter an aircraft…by condensation and precipitation (especially when an aircraft has partially filled tanks)." In addition, "The greatest single danger of water in fuel results from human error that allows fuel contaminated with water to enter an aircraft fuel system or permits an aircraft to be operated before its fuel system is properly checked for water." The pilot provided a list of items performed before, during, and after the flight. However, the list did not mention sumping the fuel during the preflight inspection. The pilot was asked by email to "confirm preflight procedures in regards to checking fuel quality." The pilot responded with the original list and stated, in part, that the "fuel and oil quantities were verified and oil quantity was addressed." A subsequent email to the pilot specifically noted not wanting to miss any information about his sumping the fuel, but the pilot did not respond. The passenger stated that he was not present for the preflight inspection. Carburetor Icing According to the POH, "Under certain moist atmospheric conditions at temperatures of -5 to 20 degrees C, it is possible for ice to form in the induction system, even in summer weather. This is due to the high air velocity through the carburetor venture and the absorption of heat from this air by vaporization of the fuel. To avoid this, carburetor preheat is provided to replace the heat lost by vaporization. Carburetor heat should be full on when carburetor ice is encountered. Adjust mixture for maximum smoothness." In addition, "Carburetor ice can be detected by a drop in rpm in fixed pitch propeller airplanes and a drop in manifold pressure in constant speed propeller airplanes. In both types, usually there will be a roughness in engine operation." Special Airworthiness Information Bulletin (SAIB) CE-14-23 On August 6, 2014, the FAA issued the SAIB, "information only, recommendations are not mandatory," to alert owners, operators and maintenance technicians of an airworthiness concern, "specifically structural deterioration and possible collapse of the air inlet hose. The air inlet hose may be between the air filter and the fuel injector, carburetor or carburetor heat box depending on the airplane model. A collapsed hose reduces airflow to the engine and could result in a rough running engine or a loss of power." Postaccident examination of the air inlet hose, revealed that it was not collapsed. Ditching The pilot indicated that he was concerned that if he landed in deeper water, the fixed landing gear airplane would flip over. No substantive documentation could be located in FAA archives regarding the probability of successfully ditching an airplane. Thus, the NTSB requested that the FAA provide any policy that addressed protecting lives and property on the ground during a loss of engine power. The request was made not only in reference to this accident, but also to a similar accident that occurred in Hilton Head Island, South Carolina, on March 15, 2010 (NTSB #ERA10LA175). According to the FAA response: "In the Pilot/Controller Glossary (P/CG), an aircraft emergency is described as 'a distress or urgency condition.' The P/CG further defines distress as 'a condition of being threatened by serious and or/imminent danger and requiring immediate assistance.' Urgency is defined as 'a condition of being concerned about safety and of requiring timely but not immediate assistance; a potential distress condition.' Title 14 of the Code of Federal Regulations includes several requirements intended, in whole or in part, to protect lives and property other than the occupants of the aircraft. Section 91.119 describes minimum safe altitudes for operations under part 91; those regulations principally require all operations to be at an altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface. That regulation further specifies operational restrictions in congested areas. Section 91.13 prohibits any person from operating an aircraft in a way that endangers the life or property of another. While not regulatory, Chapter 16 of the FAA's Airplane Flying Handbook (FAA-H-8083- 3A) describes the human factors elements associated with pilots selecting between forced landing sites, including forced landings on water (ditching). The accidents described in the NTSB's request appear to be the result of a PIC decision to land on a hard surface rather than in the water. In these cases, the only available surfaces may have been the body of water and the beach. Most pilots will instinctively look for the largest available flat and open area for an emergency landing. While ditching an aircraft is not necessarily more unsafe than a beach landing, when other options exist, pilots may tend to avoid ditching an aircraft. Ditching generally involves total loss of the aircraft, and the sudden deceleration, likelihood the aircraft overturning on touchdown, and subsequent cockpit egress difficulties can further influence this decision. A beach can also appear deceptively attractive to a pilot who is forced to make an instantaneous emergency landing decision. A beach surface is somewhat level, usually with no fixed obstacles, and can be assumed to be safe for the aircraft occupants and preservation of the aircraft. These conditions can cause a pilot to overlook the density of people on such a surface. Because of the variety of possible emergency situations, it is impractical to apply a specific policy addressing risks involved between beach landings and ditching. The FAA relies on its requirements for pilot training on aeronautical decision making to compel pilots to pursue courses of action in an emergency which appear to be the safest and most appropriate under the circumstances." On-scene photographs showed the airplane upright and nose-down at the waterline, angled slightly towards the beach with the magnetic compass indicating 350 degrees magnetic. The nose landing gear was separated from the airframe, while both fixed main landing gear remained attached. The left wing, which was extended over the water, had about 4 feet of leading edge crushing on the outboard portion of the wing, and the wingtip was undamaged. The two-blade metal propeller exhibited no damage to one blade, while the other was bent aft about 60°, beginning mid-span. Photographs of the cockpit showed the fuel was selected off, the magnetos were off, the mixture was rich, the throttle was forward and the carburetor heat was off. The pilot indicated to the FAA inspector that he had turned off the fuel and ignition after landing. The Hobbs meter indicated about 22 minutes of operating time, consistent with the pilot's recollection of 10 to 15 minutes of flight time. The wing fuel tanks were subsequently defueled, the wings were removed, and the airplane was transported to a storage facility. There, NTSB, FAA, Piper Aircraft, and Lycoming Engine investigators further documented the airframe and engine. The fuel supply line from each wing fuel tank to its disconnect point in the cockpit and each fuel tank vent line was checked via air flow and found to be unobstructed. Engine compression, magneto spark, fuel quality and engine crankshaft continuity checks were also accomplished with no anomalies noted. The fuselage with engine still attached was then strapped down to a trailer and the original onboard fuel was supplied to the fuel selector valve via a portable external tank. The engine started on the second attempt; however, with the damaged propeller, it could only safely be operated to about 900 rpm. The propeller was then removed and partially straightened to the extent of available capability, then reattached. The engine was subsequently restarted and was able to be run throughout the throttle range up to 2,000 rpm safely. Magneto checks