# NTSB SEA04LA071: Keller Prospector FK1, N5XK, Gibbonsville, ID, April 17, 2004 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: April 17, 2004, 12:00 local (18:00 UTC) - Place: Gibbonsville, ID - Coordinates: 45.690555, -113.946945 - Nearby events: https://openairdocs.org/map.md?lat=45.6906&lon=-113.9469&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report September 29, 2004 - Report: Approved by Office Director - Parties: Boise, Idaho, FSDO - NTSB case key (mKey): 59084 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA04LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59084/pdf - Page: https://openairdocs.org/ntsb/SEA04LA071 ## Probable cause The pilot's failure to apply carburetor heat in icing conditions which resulted in a loss of engine power while in cruise flight. Factors contributing to the accident are unsuitable terrain for an emergency landing , trees and mountainous terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - normal - weather condition - carburetor icing conditions (cause) - carburetor heat - not used, pilot in command (cause) - In flight collision with object, emergency descent/landing - object - tree(s) (contributing factor) - In flight collision with terrain/water, emergency descent/landing - terrain condition - mountainous/hilly (contributing factor) - terrain condition - none suitable (contributing factor) ## Analysis In a written statement the pilot reported that approximately 10 miles south of Lost Trail Pass he decided to turn back due to deteriorating weather ahead. The pilot stated that during the turn he lost track of the two other aircraft that made up the flight of three. The pilot stated he was "trying to locate [the] other two A/C [aircraft] to the exclusion of the engine instruments". The pilot stated that as the airplane reached the summit he added power "as I was too low." Concurrent with the increase in power, the engine quit. The pilot maneuvered the airplane in an effort to avoid rising terrain, however, during the maneuver the airplane collided with multiple trees eventually impacting terrain in an inverted position. The pilot rated passenger reported the weather conditions along the route of flight began to deteriorate, and the pilot-in-command of the accident airplane elected to return to Stevensville. The passenger reported that shortly after making the decision to return, the airplane's engine began to lose power. After losing power, the airplane stalled and collided with terrain. The pilot and pilot rated passenger both indicated the loss of power was the result of carburetor ice. The pilot was operating the airplane in moderate snow showers. The pilot's written report indicated the outside air temperature was approximately 35 degrees Fahrenheit. ## Factual narrative On April 17, 2004, about 1200 mountain daylight time, a Keller Prospector FK1 airplane, N5XK, sustained substantial damage after colliding with forested terrain near Lost Trail Pass, Gibbonsville, Idaho. The airplane is owned by the pilot and was being operated as a visual flight rules (VFR) cross-country flight under the provisions of 14 CFR Part 91, when the accident occurred. The pilot, and pilot rated passenger, both sustained serious injuries in the accident and were transported to area hospitals. Visual meteorological conditions prevailed; however, areas of low ceilings and reduced visibility were reported in the area of the accident. The flight originated from Stevensville, Montana, approximately 1 hour and 30 minutes prior to the accident. The pilot's planned destination was Jackpot, Nevada (06U). During a telephone conversation with the National Transportation Safety Board IIC, on April 20, the pilot rated passenger reported that the accident airplane was one of three aircraft that was flying from Montana to Nevada. The pilot rated passenger reported the weather conditions along the route of flight began to deteriorate, and the pilot-in-command of the accident airplane elected to return to Stevensville. The passenger reported that shortly after making the decision to return, the airplane's engine began to lose power. After loosing power, the airplane stalled and collided with terrain. The pilot rated passenger reported the loss of power was the result of carburetor ice. In a written statement dated May 15, 2004, the pilot reported that approximately 10 miles south of Lost Trail Pass he "decided to turn back due to deteriorating weather ahead." The pilot stated that during the turn he lost track of the two other aircraft that made up the flight of three traveling together to Jackpot. The pilot stated he was "trying to locate [the] other two A/C [aircraft] to the exclusion of the engine instruments". The pilot stated that as the airplane reached the summit he added power "as I was too low." Concurrent with the increase in power, the engine quit. The pilot maneuvered the airplane in an effort to avoid rising terrain, however, during the maneuver the airplane collided with multiple trees eventually impacting terrain in an inverted position. In the Recommendations section "How Could This Accident Have Been Prevented" of the NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), submitted on May 14, 2004, the pilot reported, in part, that the use of carburetor heat may have prevented the accident. ## Aircraft - Registration: [N5XK](https://openairdocs.org/deregistered/N5XK-2005-11-01), registration cancelled 2005-11-01, S/N 002, built 1996 (OpenAirDocs) - Reported make and model: Keller Prospector FK1 - Registry model: [Keller Fred H PROSPECTOR](https://openairdocs.org/model/keller-fred-h-prospector) (registry code 0563012) (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: 002 - Airframe hours: 618 - Engines: Lycoming O-320-E2D 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Thomas C. Kuffel - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, October 30, 2003, 34 hours before - Departed: 32S, STEVENSVILLE, MT - Destination: 06U, JACKPOT, NV - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: serious; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review September 14, 2003; seat: left; flight hours: 3,344 total, 618 in this make and model, 29 in the last 90 days, 24 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Temperature: 36 °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 20040417009189A](https://openairdocs.org/incident/20040417009189A), Apr 17, 2004: Amtr PROSPECTOR, Gibbonsville, ID, Destroyed. (-23) On 04-17-04 at 1230 pm N5XK with two persons aboard collided into the forested terrain near lost trail pass, coming to rest .5 miles south of the Idaho… 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.