Aviation Accident Summaries

Aviation Accident Summary MIA07LA032

Merritt Island, FL, USA

Aircraft #1

N286JL

Clopton Aero LLC Aerocomp Compair 7SL

Analysis

The pilot stated that he completed about 7 practice crosswind landings during which the airplane performed well with no problems. During his last takeoff at 93 percent power, while at an altitude of about 500 to 700 feet AGL, the turbine started to spool down to about 61 percent (flight idle). He said he initiated emergency procedures to include pushing the left throttle full forward, with no increase in power being realized. He said he then brought the left throttle to flight idle, feathered the propeller, flipped and activated the isolate switch to the on position to bypass the normal fuel delivery system, and then advanced the right throttle full forward. He said the lock clip detent was secure, but this produced no increase in power or thrust, Thrust remained at about 61 percent, with no change being noted in fuel power through either the normal and emergency isolate positions in fuel flow to the turbine. He said he felt he was dropping faster with the propeller feathered, so he attempted to see if he could get some thrust with the propeller control to full forward which seemed to help a little. He said he was able to glide clear of all houses and structures, and was able to ditch the airplane in the water. After recovery from the water, postcrash examinations of the airframe, engine, and accessories were performed by the manufacturer, and the examinations revealed the presence of "slime" in the common airframe fuel filter which received fuel from the normal fuel supply line, as well as the separate emergency fuel supply line that bypassed the fuel control unit, to directly feed the turbine. The engine was also given a separate detailed examination. No other anomalies were noted.

Factual Information

On December 21, 2006, about 1118 eastern standard time, a Clopton Aero LLC, model Aerocomp Compair 7SL, experimental amateur built airplane, N286JL, operated by the manufacturer Aerocomp Corporation, as a Title 14 CFR Part 91 training flight, ditched into a river in Merritt Island, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The private-rated pilot received minor injuries, and the airplane incurred substantial damage. The flight was originating at the time of the accident. The pilot stated that the accident airplane was being purchased and it was at the manufacturer's facility being modified prior to final delivery. As part of the sale he said that product familiarization and flight training were included, and that the airplane had not yet been delivered. At the time of the accident the pilot said he had accumulated about 50 flight hours in the airplane while it was at the manufacturer's facility. On the day of the accident the pilot said he performed his preflight examination, started the turbine, and taxied to runway 11. Prior to takeoff on runway 11, the pilot said he checked that all fuel valves were open and the header tank light was off. The propeller control was forward and the throttle clip lock (detent) was in-place and locked. He said he took off with 93 percent power without any problems and completed a left hand traffic pattern to a landing back on runway 11. He repeated this about 7 times to practice crosswind landings and according to the pilot, the airplane performed well, with no problems having occurred, an further stated that the turbine was smooth, and there were no vibrations or irregularities. During his last takeoff at 93 percent power, the pilot said he had climbed to about 500 to 700 feet AGL, had cleared the runway, and was at the east end off Newfound Harbor (Sikes Creek), and over the island, when the turbine started to spool down to about 61 percent (flight idle). He said he pushed the left (Normal) throttle full forward, with no increase in power being noted. According to the pilot, he looked for emergency landing spots on the island, saw none, and knew that his only choice was to affect a landing in the water. He said he started a slow standard rate turn to the left, lowered the airplane's nose to best glide speed, and trimmed the airplane. He then commenced the emergency procedures, with included retarding the normal throttle to flight idle, feathered the propeller, flipped the red cover, and activated the isolate switch to the "On" position. He then advanced the now active right (Emergency) throttle full forward, noting that the lock clip detent was secure. He stated that this action also did not result in any increase in power or thrust, and added that the thrust remained at about 61 percent. According to the pilot, there was no change in his use of the normal and emergency isolate positions and both did not result in a change in fuel flow to the turbine. The pilot said he felt that the airplane was descending faster with the propeller feathered, so he attempted to see if he could obtain some thrust with the propeller control full forward, and this seemed to help a little. After the left turn converted the original right crosswind to a tailwind, he said he was able to glide clear of all houses and structures, and prepare for an emergency ditching in the water. he felt the left wing was heavy and was going to stall first, so he lowered the nose to correct the buffet/dip, and made a mayday call stating his location and intention to ditch in the water. He said he knew that if power could not be restored with the emergency isolate procedure, which is an independent system which bypasses the fuel control unit, there was no way to return to the airport, so he continued the emergency procedures. In ground effect over the water the pilot said he tried to increase the flap angle without stalling, and began to flare. He then opened the left door and pulled the right throttle to the full back position to shut down the turbine. While keeping the wings level and the airplane in a nose high attitude, the tail hit, followed by the main landing. Upon impacting the water he said that the four point restraint kept him from hitting the panel, but his right hand on the right throttle hit the panel and instruments. The cockpit quickly filled with water and the pilot said he and is dog exited the airplane, swam, and was soon picked up by a recreational boater. The pilot also said that the airplane had flown well in slow flight, and the turbine was still spooling at the time of impact. Power loss had been smooth, with no vibrations or abnormalities noted, and the power had remained at flight idle during the descent. After recovery from the water, postcrash examinations of airplane, engine, and accessories, were examined by the manufacturer, and the examinations revealed the presence of "slime" in the common airframe fuel filter, which received fuel from both the normal fuel supply line, as well as the separate emergency by pass line which bypassed the fuel control unit, and directly fed the turbine. No other anomalies were noted. In addition, a detailed examination of the engine was performed by technicians at Diemech Turbine Solution, Incorporated, Deland, Florida, and the examination revealed information consistent with the turbine having been operating until the airplane ditched. There were no anomalies noted with the engine that would have precluded its operation.

Probable Cause and Findings

The airplane manufacturer's inadequate maintenance prior to final aircraft delivery, which resulted in fuel filter blockage and engine fuel starvation.

 

Source: NTSB Aviation Accident Database

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