History of Flight
On March 24, 2011, at approximately 1623 eastern daylight time, a Cessna A185F, registration N724MT, operated by the Maine Department of Inland Fisheries and Wildlife, was substantially damaged when it impacted frozen Clear Lake, about 30 nautical miles southwest of Ashland, Maine. The certificated commercial pilot, a Maine Game Warden, was fatally injured. Instrument meteorological conditions prevailed, and no flight plan was filed for the public-use flight.
According to the operator, the pilot had taken his usual airplane to Greenville, Maine (3B1) for maintenance, then picked up the ski-equipped accident airplane and returned to his patrol area. A game warden at Clear Lake reported overhearing the pilot attempting to call the local dispatch center about radio problems; the warden relayed the message. Shortly after, the pilot landed on Clear Lake and met with the warden.
The warden stated they talked for about 30 minutes before receiving a radio call from another warden whose snowmobile was stuck on nearby Eagle Lake. The pilot departed Clear Lake to assist. He landed on adjacent Chamberlain Lake, picked up the other warden, and they retrieved tools from a truck. They freed the snowmobile from about three feet of snow and slush. During the recovery, the pilot's boots were inundated with icy slush, and he was breathing heavily from exertion. After about 10 minutes of conversation, his breathing returned to normal. The warden reported that almost immediately after the airplane departed, visibility dropped to less than 1/2-mile due to snow.
Both wardens noted isolated heavy snow moving through the area throughout the day. The pilot was reported missing about 2000 when he did not return home. A search ensued, and the wreckage was located at about 0850 the following day.
Personnel Information
The pilot was employed by the Maine Department of Inland Fisheries and Wildlife, Maine Warden Service, as a Game Warden/Pilot. He held a commercial pilot certificate with ratings for airplane single-engine land and sea, and instrument airplane. He held a second-class medical certificate issued June 14, 2010, with a limitation to wear corrective lenses. At that time, he reported 3,130 total flight hours.
On March 13, 2011, the pilot reported 3,548 total hours of pilot-in-command experience, including 3,146 hours in the Cessna 185, with 376 hours in the preceding 12 months. He also reported 10, 70, and 2 hours of instrument flight experience in a Beechcraft BE-19, Cessna 172, and Cessna 185, respectively. His most recent flight review and instrument proficiency check were completed on April 1, 2010. Personal flight logs through September 22, 2010, showed a 1.2-hour flight on April 1, 2010, in a Cessna 185 with 0.7 hours of simulated instrument time, noting "Flight Review Completed, IPC Check Completed." Additional logs showed 19 flight hours in a Cessna 185 between that report and the accident.
Meteorological Information
The National Weather Service Surface Analysis Chart at 1400 depicted a low-pressure system off the New England coast with an occluded front, and a secondary trough extending across Maine and Quebec. A cold core high pressure was over Hudson Bay. Station models near the accident site indicated northerly winds at 5-10 knots, scattered to broken clouds, temperatures near 0°C, and dewpoint several degrees lower. The 1700 chart showed similar conditions.
The Weather Depiction Chart at 1500 showed an area of IMC over northwest and southwest Maine into Quebec, surrounded by marginal VMC over western Maine and the accident site, with VMC over eastern Maine.
At Ilco Landing Area Seaplane Base (ME04), 16 miles west, at 1625, winds were variable at 3 knots, temperature -3°C, dewpoint -4°C, altimeter 29.67 inHg. Less than 0.01 inches of precipitation fell in the previous hour. Visibility, weather, and cloud cover were not reported.
Satellite imagery at 1615 showed broken low cumulus clouds over northern Maine in an open cellular pattern, with the accident site near the leading edge. Infrared imagery indicated cloud tops near 5,000 feet.
WSR-88D radar at Caribou, Maine, 62 miles east-southeast, at 1617:53 showed very light echoes (5-24 dBZ) across the region, with the accident site under about 20 dBZ echoes, likely light snow showers. A scan at 1627:32 showed the echo remained at 20-24 dBZ and moved southward.
The NWS Area Forecast valid from 1345 to 0200 on March 25 expected broken clouds at 4,000 feet with tops to 9,000 feet and occasional light snow showers. Outlook from 0200 to 0800 was VMC. AIRMET Sierra update 2 for mountain obscuration bounded an area just south of the accident site, and AIRMET Zulu for icing conditions below 8,000 feet encompassed the accident site.
The airplane was equipped with a Garmin GPSMAP 496 handheld GPS with satellite weather data receiver and current subscription for METARs, SIGMETs, AIRMETs, and NEXRAD.
Wreckage and Impact Information
The wreckage was on frozen, snow-covered Clear Lake at 46°30.95'N, 69°7.97'W. There was fuel odor and staining. All major components were accounted for. The initial impact point was broken ice about 10 feet long and 6 feet in diameter. The wreckage path was oriented approximately 100° magnetic and about 350 feet long. Right wingtip, strut, horizontal stabilizer and elevator, engine intake air filter, right main landing gear, and other debris were found along the path. The main wreckage came to rest at about 60° magnetic.
The right wing separated from the root but remained attached by control cables; the outboard two-thirds was crushed and bent upward and aft. The left wing remained attached to the cabin roof with little structural distortion. The left horizontal stabilizer and elevator remained attached; the right horizontal stabilizer and elevator were largely separated. Flight control continuity was traced through overload separations. The stabilator trim actuator corresponded to 5-6 degrees of nose-up pitch.
The cockpit and cabin exhibited extensive impact damage. The altimeter kollsman window was set to 29.67 inHg. Rotating beacon, navigation lights, and pitot heat switches were in the "ON" position.
The vacuum pump drive coupling was sheared; the injection-molded plastic coupling showed torsional deformation and a fracture with flat region and elongated fibrils. Disassembly showed two of six veins with small area damage; the rotor showed no damage, and the housing had five faint slap marks. The shaft rotated smoothly. Examination of vacuum-driven gyros revealed no definitive rotational state signatures.
The three-blade constant-speed propeller separated from the engine by a crankshaft fracture aft of the forward engine case. The propeller came to rest about 20 feet forward of the main wreckage. Two blades had s-bending and leading edge gouging; the third blade was bent aft about one-third of its span.
The engine was separated from the airframe; crankshaft continuity was confirmed. Borescope inspection revealed no abnormal combustion deposits; spark plugs showed normal wear and light gray color. Induction air filter and fuel screens were clean. Magneto timing was confirmed, and spark was produced at each terminal lead.
A handheld GPS receiver was recovered and retained for examination.
Medical and Pathological Information
An autopsy performed by the Office of the Chief Medical Examiner, Augusta, Maine, listed the cause of death as "blunt injuries." The FAA's Bioaeronautical Sciences Research Laboratory performed toxicology; results were negative for carbon monoxide, cyanide, ethanol, or drugs.
Additional Information
Handheld GPS Receiver Data
The Garmin GPSMAP 496 was damaged but repaired sufficiently to download waypoint, route, and track log data. Track log data showed flights consistent with witness statements, including the flight from Clear Lake to Chamberlain Lake and the accident flight.
The final flight track began at 1613, departing Chamberlain Lake, turning northeast, and climbing to about 1,500 feet GPS altitude, heading toward Eagle Lake. About 1619, the track turned about 20 degrees left toward Clear Lake. Terrain elevation below the track varied from about 980 to 1,350 feet, while GPS altitude remained around 1,500 feet.
At 1622:13, the airplane slowed from about 120 knots groundspeed to 110 knots 30 seconds later. At 1622:30, the track turned about 40 degrees left, about 1/2-mile south of Clear Lake. At 1622:49, the airplane crossed the southern bank of Clear Lake at a GPS altitude of 1,480 feet. The final three GPS positions were recorded between 1622:55 and 1622:59, showing altitude decreasing from 1,481 to 1,423 to 1,297 feet, with descent rates of 1,740 and 3,780 feet per minute. The track turned from northwest to east at an average turn rate of 11 degrees per second.
The initial impact point was about 230 feet southeast of the final GPS position, at an elevation of 1,197 feet, along a heading consistent with the ground track between the final two positions.
Automated Flight Following Data
The airplane was equipped with an automated flight following system transmitting position via satellite every 10 minutes. Data recorded one position during the accident flight at 1615:36, about 7 minutes before and 13.5 nautical miles southwest of the accident site.
Operator Policy Document
The operator's Aviation Policy #30 stated pilots must "accept and conduct only those flights that can be made in a safe and efficient manner." Administrative flights were to comply with 14 CFR Parts 91 and 61; other flights were public use. When operating under IFR, pilots were to ensure recent flight experience per 14 CFR 61.57.
Restrictions to Visibility in Snow
The FAA publication "General Aviation Pilot's Guide" described "flat light" as a condition where diffused light eliminates shadows, preventing judgment of distance and depth, especially over snow or water. The American Meteorological Society defined "whiteout" as engulfment in a uniformly white glow with loss of horizon and depth perception, often over unbroken snow cover and uniformly overcast sky. Transport Canada's Aeronautical Information Manual described precipitation whiteout from small wind-driven snow crystals falling from low clouds, reducing visibility and depth perception to nil.