# NTSB CHI94LA224: Cessna 150, N9284U, Andover, MN, July 8, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 8, 1994, 08:15 local (13:15 UTC) - Place: Andover, MN - Coordinates: 45.2499, -93.329895 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.2499&lon=-93.3299&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 24, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9588 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA224 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9588/pdf - Page: https://openairdocs.org/ntsb/CHI94LA224 ## Probable cause the flight instructor's improper procedures and directives by electing to pull the mixture control to the 'off' position during simulated emergency procedures. A factor associated with the accident is the existence of weather conditions conducive to carburetor icing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, maneuvering - mixture control - switched off - procedures/directives - improper, pilot in command(cfi) (cause) - weather condition - carburetor icing conditions (contributing factor) - fuel system,carburetor - ice - Forced landing, descent - emergency - On ground/water collision with object, landing - roll ## Analysis THE FLIGHT INSTRUCTOR AND PRIVATE PILOT WERE PRACTICING EMERGENCY PROCEDURES WHILE ON A BIENNIAL FLIGHT REVIEW. THE INSTRUCTOR REPORTED THAT HE INITIALLY REDUCED THE THROTTLE TO SIMULATE A ROUGH ENGINE, AND THEN PULLED THE MIXTURE OUT (TO THE 'OFF' POSITION)TO SIMULATE AN ENGINE FAILURE. THE PRIVATE PILOT SUBSEQUENTLY PULLED CARBURETOR HEAT TO 'ON' AND PERFORMED OTHER EMERGENCY PROCEDURES. THE INSTRUCTOR WAS SATISFIED WITH THE PILOT'S RESPONSE, AND TOLD HIM TO RESTORE THE ENGINE POWER. THE ENGINE DID NOT REGAIN POWER WHEN THE MIXTURE WAS PUSHED IN. THE INSTRUCTOR MADE AN EMERGENCY LANDING ON A NEARBY LAWN/FIELD, STRIKING OBSTRUCTIONS DURING THE LANDING ROLL. THE REPORTED TEMPERATURE IN THE AREA AT THE TIME OF THE ACCIDENT WAS 61 DEGREES AND THE DEW POINT WAS 59 DEGREES. THESE TEMPERATURES FALL WITHIN THE SEVERE ICING RANGE ON A CARBURETOR PROBABILITY CHART. THE AIRPLANE'S ENGINE WAS STARTED AND RUN AT THE ACCIDENT SITE WITHOUT ANY OBSERVED MECHANICAL DEFICIENCIES. ## Factual narrative On July 8, 1994, at 0815 central daylight time, a Cessna 150, N9284U, sustained substantial damage following a loss of engine power and subsequent off-airport forced landing near Andover, Minnesota. The certificated flight instructor and private pilot aboard reported no injuries. The 14 CFR Part 91 instructional flight originated in Anoka, Minnesota, at 0800. No flight plan was filed, and visual meteorological conditions prevailed at the time. According to the instructor's statement, he reduced the engine power to simulate a rough running engine, and than pulled the mixture control out to simulate an engine failure. He said the private pilot did an excellent job of remedial emergency procedures, including pulling the carburetor heat "on" promptly. The instructor wrote that he was satisfied with the private pilot's actions, and told him to restore power. When the private pilot pushed the mixture in to full rich, the engine would not restart. The instructor took control of the airplane and made a forced landing on a nearby field. He was unable to stop the airplane prior to colliding with obstructions. The reported surface temperature in the area at the time of the accident was 61 degrees and the dew point was 59 degrees. The attached Carburetor Icing Probability Chart places this temperature and dewpoint combination in the severe icing category. Postaccident inspection of the airplane and its systems discovered no preimpact mechanical anomalies. The engine was started and run at the site with no observed mechanical deficiencies. ## Aircraft - Registration: [N9284U](https://openairdocs.org/deregistered/N9284U-1998-08-27), registration cancelled 1998-08-27, S/N 15078234 (OpenAirDocs) - Reported make and model: CESSNA 150 - Registry model: [Cessna 150M](https://openairdocs.org/model/cessna-150m) (registry code 2071830) (OpenAirDocs) - Category: Airplane - Serial number: 15078234 - Engines: CONTINENTAL O-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Flywell Flying Club Inc. - Registered owner: Flywell Flying Club Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 16, 1993 - Departed: ANE, ANOKA, MN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 14,000 total, 400 in this make and model, 13,394 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 10 knots - Visibility: 12 statute miles - Lowest ceiling: 2,300 ft overcast - Temperature: 63 °F, dew point 57 °F - Altimeter: 29.00 inHg - Observed at: STP, 13 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 19940708018069A](https://openairdocs.org/incident/19940708018069A), Jul 8, 1994: Cessna 150M, Andover, MN, Substantial damage. Forced landing. Unable substantiate engine failure. Carubretor ice chart and use of mix turf explained to pilot. ## Other investigations on N9284U (1) 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. - [NTSB MKC78DER27](https://openairdocs.org/ntsb/MKC78DER27), Feb 13, 1978: Cessna 150 (N9284U), St.Paul, MN, substantial damage 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.