# NTSB DEN05LA106: Clarke YAK 3UR 2000, N134US, Heber City, UT, July 9, 2005 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: July 9, 2005, 09:15 local (15:15 UTC) - Place: Heber City, UT - Coordinates: 40.481945, -111.428886 - Nearby events: https://openairdocs.org/map.md?lat=40.4819&lon=-111.4289&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report April 25, 2006 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 61913 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN05LA106 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61913/pdf - Page: https://openairdocs.org/ntsb/DEN05LA106 ## Probable cause loss of engine power due to a leaking carburetor and an inoperative float, and the pilot's failure to maintain aircraft control during the restart attempt. Contributing factors were the sudden engine power surge during the attempted restart, and unsuitable terrain on which to make a forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, approach - vfr pattern - downwind - fuel system,carburetor - leak (cause) - fuel system,carburetor float - inoperative (cause) - Forced landing, descent - emergency - Loss of control - in flight, descent - emergency - aircraft control - not maintained, pilot in command (cause) - remedial action - attempted, pilot in command - miscellaneous,engine - surge (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - none suitable (contributing factor) - terrain condition - ground ## Analysis When the airplane turned downwind, the engine lost power. The pilot attempted to restart the engine, and it surged suddenly. The torque caused the airplane to roll inverted. The pilot managed to roll the airplane upright, but was unable to restart the engine and he made a forced landing on airport property, striking the ground hard and substantially damaging the airplane. Examination and tesing of the carburetor revealed the enrichment cover was leaking, and there was "a substantial leak" at one of the vapor vent ports. One of the vapor vent floats was not functioning. When the vapor vent port was plugged, the carburetor tested between 7 and 22 pounds per hour above the rich limit. ## Factual narrative On July 9, 2005, at 0915 mountain daylight time, a YAK 3UR 2000, N134US, piloted by a airline transport pilot, sustained substantial damage when it impacted terrain during a forced landing near Heber City Airport, Heber City, Utah. Visual meteorological conditions prevailed at the time of the accident. The local personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot and passenger sustained minor injuries. The flight originated in Caldwell, Idaho, and was destined for Heber City, Utah. In a telephone interview, the pilot said that when he turned downwind, the engine lost power. When he attempted to restart the engine, it surged and the torque caused the airplane to roll inverted. The pilot managed to roll the airplane upright, but was unable to restart the engine. He said he "planted" the airplane on the ground. The airplane "bounced ten times" and came to rest 200 to 250 yards from the initial impact point. The engine was torn away from the fuselage. The carburetor was examined at Precision Engines Corporation in Everett, Washington, and a report issued. The report noted that the enrichment cover was leaking, and there was "a substantial leak" at one of the vapor vent ports. One of the vapor vent floats "does not appear to be functioning correctly," the report said. The vapor vent port was plugged and the carburetor was functionally tested. The carburetor tested between 7 and 22 pounds per hour above the rich limit on test points 1 through 16. All other test points were within limits, as was the automatic mixture control. ## Aircraft - Registration: [N134US](https://openairdocs.org/aircraft/N134US), registered now, S/N DMC0003 (OpenAirDocs) - Reported make and model: Clarke YAK 3UR 2000 - Registry model: [Clarke Dale M YAK 3UR 2000](https://openairdocs.org/model/clarke-dale-m-yak-3ur-2000) (registry code 05601JM) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-2000 series](https://openairdocs.org/engine/pratt-whitney-r-2000-series) (registry code 52023, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: DMC0003 - Airframe hours: 115 - Engines: Pratt & Whitney R 2000 7M2 1600 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Holbrook Maslen - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, June 1, 2005, 7 hours before - Departed: EUL, Caldwell, ID - Destination: 36U, Heber City, UT - Airport: 36U, Heber City Mun.-Russ McDonald ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: minor; airline transport, flight engineer, commercial; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 1, 2004; seat: rear; flight hours: 23,800 total, 125 in this make and model, 7 in the last 90 days, 7 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 34 °F - Altimeter: 29.88 inHg - Observed at: PVU ## 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 20050709012939A](https://openairdocs.org/incident/20050709012939A), Jul 9, 2005: Amtr YAK3UR2000, Heber, UT, Substantial damage. (-23) Aircraft accident. Yak 3U R2000. Hever, UT, July 9, 2005. The pilot stated that on entering the airport landing pattern, in a 45 degree bank, the engine… 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.