# NTSB CHI94DEP01: Krotje Kolb Mark III, N393PK, Oshkosh, WI, November 28, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: November 28, 1993, 12:46 local (18:46 UTC) - Place: Oshkosh, WI - Coordinates: 44.059516, -88.539299 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.0595&lon=-88.5393&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 7, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9344 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94DEP01 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9344/pdf - Page: https://openairdocs.org/ntsb/CHI94DEP01 ## Probable cause THE LACK OF CARBURETOR HEAT FOR THE ENGINE. A FACTOR RELATED TO THE ACCIDENT WAS: THE WEATHER CONDITION, WHICH WAS FAVORABLE FOR FORMATION OF CARBURETOR ICE. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, approach - vfr pattern - base leg/base to final - weather condition - carburetor icing conditions (contributing factor) - carburetor heat control - not installed (cause) - carburetor heat - not possible - Forced landing, descent - emergency - In flight collision with object, landing - object - wire,static (contributing factor) - In flight collision with terrain/water, descent - uncontrolled ## Analysis THE ENGINE SUSTAINED A LOSS OF POWER, WHILE THE AIRPLANE WAS IN THE PATTERN FOR LANDING. THE PILOT WAS UNABLE TO REACH THE RUNWAY OF INTENDED LANDING AND MADE A FORCED LANDING IN A FIELD. WHILE MANEUVERING TO LAND, THE AIRPLANE STRUCK A SUSPENDED WIRE AND IMPACTED THE TERRAIN. THE AMATEUR BUILT AIRPLANE WAS NOT EQUIPPED WITH A PROVISION FOR ELIMINATING CARBURETOR ICING. THE TEMPERATURE AT THE TIME OF THE ACCIDENT WAS 28 DEGREES, AND THE DEWPOINT WAS 18 DEGREES. THESE CONDITIONS WERE CONDUSIVE TO THE FORMATION OF CARBURETOR ICE. ## Factual narrative HISTORY OF FLIGHT On November 29, 1993, at 1246 CST, an amateur built Kolb Mark III, N393PK, registered to Peter R. Krotje, executed a forced landing in a field due to engine failure, while on right base leg to runway 31 at Wittman Regional Airport, Oshkosh, Wisconsin. The flight was conducted under 14 CFR 91 and was a local personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was substantially damaged and the owner, private pilot, Peter R. Krotje, was not injured. The flight originated at Oshkosh, Wisconsin on November 28, 1993, at 1130 CST. DAMAGE TO AIRCRAFT The aircraft received substantial damage upon impact with the terrain, shearing of the right landing gear, bending the fuselage and left landing gear, and tearing a hole in the nose cone. AIRCRAFT INFORMATION The aircraft was home-built and certified as experimental. In as much as the aircraft was experimental, no requirement existed for the use of approved parts, systems, or hardware. The aircraft was not equipped with a system to eliminate carburetor ice and at the time was utilizing automotive fuel. TEST AND RESEARCH FAA Airworthiness Inspector, Karen E. Belnay, of the Milwaukee, Wisconsin, Flight Standards District Office, tested the Rotax engine. The engine was started, tested, and ran normally. ADDITIONAL DATA The pilot stated that when he reduced power for landing the engine quit and could not be restarted. He said he was unable to glide to the airport for landing due to his position on right base and the effect of the wind. The pilot stated he did not see a powerline in enough time to avoid contact with it and that said contact slowed him so much that he could not adequately control the impact during landing in the field. The outside air temperature at the time of the accident was 28 degrees Fahrenheit with a dew point of 18 degrees Fahrenheit. According to icing probability charts, these conditions are conducive to the formation of carburetor ice. ## Aircraft - Registration: [N393PK](https://openairdocs.org/deregistered/N393PK-2013-08-23), registration cancelled 2013-08-23, S/N M3-122, built 1993 (OpenAirDocs) - Reported make and model: KROTJE KOLB MARK III (KOLB MARK) - Registry model: [Krotje Peter R KOLB TWINSTAR MK III](https://openairdocs.org/model/krotje-peter-r-kolb-twinstar-mk-iii) (registry code 05624A1) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: M3-122 - Airframe hours: 16 - Engines: ROTAX 582LC 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Peter R. Krotje - Registered owner: Peter R. Krotje - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Continuous airworthiness, October 22, 1993, 16 hours before - Departed: OSH - Destination: OSH - Airport: OSH, Wittman Regional ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; private; airplane ratings: single-engine land; medical: class 3, unknown; seat: left; flight hours: 120 total, 14 in this make and model, 72 as pilot in command, 14 in the last 90 days, 12 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 11 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 28 °F, dew point 18 °F - Altimeter: 29.00 inHg - Observed at: OSH, 1 nm away ## 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 19931128044619A](https://openairdocs.org/incident/19931128044619A), Nov 28, 1993: Amtr KOLBMK3, Oshkosh, WI, Substantial damage. Engine quit on landing approach. Struck unseen powerline. Impact short of runway. Carburetor icing prevalent. 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.