ERA12LA227

The pilots’ inadequate use of carburetor heat, which resulted in carburetor icing and a subsequent loss of engine power.

The pilot/owner had been in a previous airplane accident which resulted in traumatic brain injuries. Subsequent to that accident, he acquired an experimental amateur-built airplane, which he would only taxi because of his lack of medical clearance. Anticipating a return to medical status, the pilot asked another pilot to serve as pilot in command and fly with him to another airport for the airplane's condition inspection.There were no witnesses to the engine start, taxi time, or takeoff to the north. An air traffic controller at a nearby air force base was contacted by one of the pilots, who reported that the airplane just departed the airport, as was the custom. The controller then attempted to contact the airplane twice to determine the pilots' intentions but received no response. Radar data indicated a brief, primary (skin paint) return at the time, but no track or altitude could be determined. During the initial climb, a witness saw the airplane when it was about halfway down, and about 300 to 400 feet above the runway, and heard a power reduction. The airplane did not turn to return to the runway, but continued straight ahead over trees, and the witness eventually lost the sound of the engine. A motorist subsequently saw the airplane, gliding south, back toward the departure airport with the propeller stopped, before he lost sight of it behind trees. The airplane later impacted trees, wings level, heading eastbound, just north of a new highway. Because both pilots were ejected from the airplane, it was not possible to determine which pilot had been in which seat or who was flying. The engine had also separated from the main wreckage, which likely altered the positions of the engine controls, including the carburetor heat. Torsional bending of one of the propeller blades, as well as malleable bending (heating) of the exhaust system indicated that the engine was under some power at impact; an examination of the engine did not reveal any malfunctions or failures that would have precluded normal operation. Dark spark plug electrodes were noted and are consistent with a very rich mixture, either from carburetor icing or carburetor heat, or both. Weather data recorded near the time of the accident indicated an outside air temperature of 82 degrees F and a dew point of 64 degrees. Carburetor icing probability charts indicated the likelihood of serious carburetor icing at glide power for the temperature and dew point conditions. Because one of the pilots made a normal departure call, the effects of carburetor ice were probably first noticed subsequent to that call. At some point, the engine lost power and the pilots attempted to turn back toward the airport. They were then likely able to at least regain at least some power, likely by applying carburetor heat, but were too low to recover.

HISTORY OF FLIGHT On March 15, 2012, about 1255 central daylight time, an experimental amateur-built Emeraude CP-301-A, N718PP, was destroyed when it impacted trees and terrain while returning to Ruckel Airport (FL17), Niceville, Florida. The two airline transport pilots were fatally injured. Visual meteorological conditions prevailed. No flight plan had been filed for the personal flight to Yellow River Airstrip (FD93), Holt, Florida, which was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the responding Federal Aviation Administration (FAA) inspector, one of the pilots, who was also the owner of the airplane, had previously lost his FAA medical certificate due to injuries sustained in an earlier accident, and was about 2 weeks from qualifying for a new one. The pilot/owner, who was not the airplane's original builder, had intended to fly it to FD93 to undergo a condition inspection, but needed the other pilot onboard to act as pilot in command. The inspector also reported that the mechanic who was going to do the condition inspection stated that when the pilot/owner contacted him, he did not express any concerns about the airworthiness of the airplane. According to statement by an air traffic control specialist at nearby Eglin Air Force Base, about 1250, he received a transmission from the airplane that it had just departed from FL17 [as was the custom for airplanes from that airport.] The controller then attempted to contact the airplane twice to determine the pilot's intentions, but received no response. The controller did not recall seeing a primary (skin paint) radar return at the time. An air traffic supervisor at Eglin reported that a playback of radar data indicated brief primary radar contact with the airplane, but no track or altitude could be ascertained. According to a witness who was at the north end of the takeoff runway on the west side, the airplane took off heading north. When the airplane was about halfway down, and about 300 to 400 feet above the runway, the witness heard a power reduction. The airplane did not turn to return to the runway, but continued straight ahead over trees, and the witness eventually lost the sound of the engine. A few minutes later, the witness heard the sound of sirens. Another witness, who lived near FD93 and was accustomed to seeing airplanes, stated that he was driving southbound on route 285 northwest of the FL17, and about ¼ mile north of the new bypass interchange, when he saw the airplane from the side, about ½ mile away, with the propeller stopped. The wings were level, the airplane was descending at an angle of about 45 degrees, and he thought that the airplane was gliding into FL17, but lost sight of it behind trees. PERSONNEL INFORMATION The pilot/owner of the airplane, age 59, held an airline transport pilot certificate with ratings for single engine land and multi-engine land airplanes. The pilot's computer logbook indicated 8,549 total flight hours, but did not break down hours into single engine or multi-engine time. The pilot was also a retired U.S. Air Force and former corporate pilot, and had previously built and flown an Avid Flyer On June 9, 2008, the pilot/owner was involved in an accident with the Avid Flyer, NTSB identification number NYC08FA211, that resulted in traumatic brain injuries. FAA records indicated that the pilot/owner had subsequently been denied medical certificates, but according to his wife, he was having the airplane inspected in anticipation of a favorable outcome from his latest request. The pilot in command, age 66, held an airline transport pilot certificate with ratings for single engine land, single engine sea, and multi-engine land airplanes, and rotorcraft-helicopter. He also held flight instructor and mechanic certificates. On his latest FAA first class medical certificate application, the pilot reported 2,500 hours of civilian flight time. According to the pilot's wife, his logbook was on a computer that no longer functioned, but during his 27 years in the U.S. Navy, including his time a carrier air group commander, his wife estimated that he had flown 4,000 to 5,000 hours. The pilot's wife also stated that the reason he was onboard the airplane was because the pilot/owner could not legally fly it solo until he received medical approval from the FAA. AIRCRAFT INFORMATION FAA records indicated that the airplane was first registered to the pilot/owner on March 29, 2011. Photographs of partially charred logbook records indicated that the latest condition inspection (required yearly of experimental aircraft; certified aircraft undergo annual inspections) occurred on January 21, 2011. The airplane was powered by a Continental O-200-A engine. According to the pilot/owner's wife, he did not fly the airplane while waiting for his medical situation to resolve, but did start and taxi it around. She also noted that the previous owner had hangared the airplane at another airport in north Okaloosa County when they bought it. A mechanic fixed some items and completed a condition inspection, then the previous owner flew it to FL17. From what the pilot/owner's wife understood from her husband, the pilot in command had flown the airplane when it was hangared at the other airport, but had not flown it since it was relocated to FL17. METEOROLOGICAL INFORMATION Weather, recorded at an air force base about 5 nm to the southwest, at 1256, included scattered clouds at 5,000 feet, a broken cloud layer at 20,000 feet, wind from 140 degrees true at 6 knots, visibility 10 statute miles, temperature 28 degrees C (82 degrees F), dew point 18 degrees C (64 degrees F), and an altimeter setting of 30.24 inches Hg. WRECKAGE AND IMPACT INFORMATION According to an Okaloosa County Sheriff's Office report, the wreckage was located in the vicinity of 30 degrees, 32.244 minutes north latitude, 086 degrees, 26.178 minutes west longitude, or about ½ nautical mile, 010 degrees magnetic from the threshold of FL17 runway 18. Upon arrival at the scene, deputies found the airplane on fire, and that both pilots and the engine were located about 60 to 80 feet forward of the main wreckage. The FAA inspector and a representative from the engine manufacturer documented the accident scene. The wreckage path, which was oriented along a heading about 080 degrees magnetic, began in tree tops about 15 feet above the ground, about 30 feet before an initial ground impact point, and 75 feet prior to where the main wreckage came to rest. The FAA inspector also noted that the trees receiving the initial strikes did not extend up beyond the other trees, and that the initial strikes from both wings were at the same height, consistent with a wings-level attitude at the time. All flight control surfaces were accounted for at the accident site. Control cable continuity was established from the cockpit to the control surfaces in the tail. Control tubes to the ailerons were separated from their respective mounting locations and exhibited signatures consistent with overload. The engine was still attached to the firewall, and both were found separated from the main wreckage. The engine crankshaft was rotated to confirm continuity. Each of the four piston cylinders was borescoped with no anomalies noted. Thermal damage and melting precluded further documentation of the accessory section, the carburetor, the left magneto and the ignition leads. The right magneto could not be rotated. A photograph of the exhaust system revealed malleable bending. Photographs by the engine manufacturer representative of the upper spark plugs indicated dark coloring. The representative did not remove the lower spark plugs, but did a borescope examination of the engine cylinders, with no anomalies noted. Coloring of the lower spark plugs was not documented, and the representative has since left the company. The position