# NTSB SEA02LA071: Brunger Osprey II, N56GB, Orofino, ID, April 21, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 21, 2002, 10:30 local (17:30 UTC) - Place: Orofino, ID - Coordinates: 46.480548, -116.120964 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.4805&lon=-116.1210&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 24, 2002 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 54571 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54571/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54571 - Page: https://openairdocs.org/ntsb/SEA02LA071 ## Probable cause The aircraft's inadequate carburetor heat air box system, leading to an accumulation of ice in the carburetor throat during final approach to landing. Factors include carburetor icing conditions, the pilot's failure to correctly judge the height of the aircraft above the landing surface, and the pilot's total lack of experience in executing water landings. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, approach - vfr pattern - final approach - fuel system,carburetor - ice (cause) - carburetor heat,air box - inadequate (cause) - weather condition - icing conditions (contributing factor) - In flight collision with terrain/water, emergency descent/landing - flare - misjudged, pilot in command (contributing factor) - lack of total experience in type operation, pilot in command (contributing factor) ## Analysis After performing on-ground test runs of the recently purchased experimental amphibious aircraft, the pilot took off in order to perform maneuvers that would help him become familiar with the feel and performance of the airplane. After performing maneuvers for about 55 minutes, the pilot established the aircraft on a five-mile straight-in final approach for a full-stop landing. As he reduced the power below 2,000 rpm, he applied full carburetor heat. About one mile from the end of the runway, the engine started to run rough and then quit. During the attempted forced landing, the pilot, who does not hold a seaplane rating, flared too high, and while he was attempting to correct for the misjudged height, one of the aircraft's wings impacted the water and sustained substantial damage. A post-accident inspection of the engine revealed that the carburetor heat warm air collection shroud was approximately half the size of the equivalent shroud used on Lycoming O-320 series engines mounted on certified aircraft. In addition is was discovered that the carburetor heat box butterfly valve fit loosely and did not have sealing material on its edge. The inspection also revealed that a number of coils of the support wire inside that scat tubing that directs hot air to the carburetor throat had collapsed. Using the FAA/DOT Carburetor Icing Probability Chart, it was determined that at the time of the accident, the aircraft was operating in ambient conditions that were conducive to moderate icing at cruise power and serious icing a glide power. ## Factual narrative On April 21, 2002, approximately 1030 Pacific daylight time, an experimental Osprey II amphibious airplane, N56GB, sustained substantial damage during an attempted forced landing on the Clearwater River, near Orofino, Idaho. The commercial pilot, who was the sole occupant, was not injured, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 pleasure flight, which departed Orofino Municipal Airport about 60 minutes earlier, was being operated in visual meteorological conditions. No flight plan had been filed. The ELT, which was activated by the impact, was turned off after the aircraft was recovered. According to the pilot, he recently purchased the experimental aircraft, which had accumulated about 80 hours total time since it was manufactured, and this was his first flight in it as sole manipulator of the controls. He performed high-speed taxi tests the previous day, and also prior to takeoff on the day of the accident. After departing the airport, he proceeded to an area about five miles to the west, where he practiced various flight maneuvers in order to become comfortable with the aircraft's feel and response. After completing these maneuvers, he established a straight-in descending final approach to the easterly runway. As he reduced the engine power below 2,000 rpm, he applied full carburetor heat. About one mile from the airport, the aircraft's engine began to run rough, and soon thereafter stopped producing power. At that point, the pilot turned on the electric fuel pump, checked the mixture, and tried pumping the throttle. Being unable to restart the engine, and believing that he could not stretch his glide to the end of the runway, he attempted a forced landing on the nearby river. During the landing, the pilot, who does not hold a seaplane rating, flared too high and during his attempt to correct for the misjudged height, one wing impacted the surface of the water. An FAA Airworthiness Inspector conducted a post-accident inspection of the engine and its subsystems, and discovered that the aircraft's carburetor heat system was inadequate to supply sufficient warm air to the carburetor throat. In addition to the fact that the hot air collection muff was approximately half the size of those found on type-certificated aircraft with the same series Lycoming O-320 engine, the carburetor heat box butterfly valve fit loosely and did not have sealing material on the edge that separated cold air from hot. The inspector also found that some of the support wire in the scat tubing that delivered the hot air to the carburetor throat had collapsed. It was also determined that according to the FAA/DOT Carburetor Icing Probability Chart, the ambient conditions at the time of the accident were conducive to moderate icing at cruise power and severe icing at glide power. ## Aircraft - Registration: [N56GB](https://openairdocs.org/aircraft/N56GB), registered now, S/N 56, built 1997 (OpenAirDocs) - Reported make and model: Brunger Osprey II - Registry model: [Brunger OSPREY II](https://openairdocs.org/model/brunger-osprey-ii) (registry code 9570520) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 56 - Airframe hours: 80 - Engines: Lycoming O-320-E3D 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: David K. Parker - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, October 13, 2001, 16 hours before - Departed: S68, Orofino, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: none; commercial; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; last flight review April 8, 2001; seat: left; flight hours: 700 total, 2 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 55 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20020421007679A](https://openairdocs.org/incident/20020421007679A), Apr 21, 2002: Amtr OSPREY2, Lincoln, MT, No damage. (-23) Commercial pilot david parker was on his maiden flight in the exp. Oxprey ii amphibous aircraft with 80 total hours total time on it. He had been flying… ## Docket (2 files) The files NTSB released with the investigation on September 15, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54571. 368 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 311 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432519&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Carburetor Icing Probability Chart (item 2, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40165741&FileExtension=.PDF&FileName=FAA%20Carburetor%20Icing%20Probability%20Chart-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.