# NTSB BFO93LA112: Cessna 172, N7954U, Normalville, PA, July 6, 1993 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 6, 1993, 15:15 local (19:15 UTC) - Place: Normalville, PA - Coordinates: 40.010765, -79.420799 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.0108&lon=-79.4208&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report May 17, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 8786 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO93LA112 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8786/pdf - Page: https://openairdocs.org/ntsb/BFO93LA112 ## Probable cause THE PRESENCE OF CARBURETOR ICING CONDITIONS, WHICH CAUSED A TOTAL LOSS OF ENGINE POWER. A FACTOR RELATED TO THE ACCIDENT WAS THE PILOT'S DELAYED USE OF CARBURETOR HEAT AND ROUGH 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) - fuel system,carburetor - ice (cause) - carburetor heat - improper use of, pilot in command (cause) - Forced landing, descent - emergency - Nose over, landing - flare/touchdown - terrain condition - rough/uneven (contributing factor) ## Analysis THE PILOT REPORTED THAT THE ENGINE BEGAN TO 'RUN ROUGH' ABOUT 20 MINUTES AFTER DEPARTURE DURING CRUISE FLIGHT AT 5,500 FEET. HE STATED THAT HE APPLIED CARBURETOR HEAT, BUT THE ENGINE 'QUIT COMPLETELY'. A FORCED LANDING WAS EXECUTED. THE AIRPLANE LANDED ON ROUGH TERRAIN AND NOSED OVER. AN FAA AVIATION SAFETY INSPECTOR EXAMINED THE AIRPLANE AND STATED THAT 'CARBURETOR ICING IS SUSPECTED'. THE ENGINE WAS SUCCESSFULLY RUN AFTER THE ACCIDENT. ## Factual narrative On July 6, 1993, about 1515 hours eastern daylight time, N7954U, a Cessna 172, owned by Richard A. Wilkinson and Larry W. Brubaker of Curwensville, Pennsylvania, sustained substantial damage during a forced landing in a field near Normalville, Pennsylvania. The pilot and two passenger received minor injuries. Visual meteorological conditions prevailed and a flight plan was not filed. The cross country flight departed Morgantown, West Virginia, at about 1450 hours and was destined for Clearfield, Pennsylvania. The personal flight was conducted under 14 CFR Part 91. According to the pilot, the airplane had just been purchased by the two passengers and was being ferried to the Clearfield Lawrence Airport in Clearfield, Pennsylvania. The pilot stated, "After departure at 5500 feet the mixture was leaned. Within a few minutes, the engine began to run rough. The mixture was selected rich, carburetor heat was applied, [and the magnetos] were checked. Checked fuel selector valve to [left tank] through BOTH to [right] tank and back to BOTH. Engine quit completely. Emergency landing area was selected. Turned final to selected area on [a heading of about 250 degrees]. Landed [about] 150 feet of selected field. . . . " According to a Federal Aviation Administration (FAA) aviation safety inspector, post accident examination of the airplane and accident site revealed the airplane contacted the ground, slid 45 feet, and then nosed over. According to the inspector, "The aircraft was righted, a continuity inspection of the engine and fuel system was satisfactory, inspection of several spark plugs revealed a dark brown color that was not supported by the exhaust, carburetor ice is suspected. Installed spark plugs, cleared exhaust and intake, started engine, limited to 1000 [revolutions per minute] because of bent propeller, magnetos checked satisfactory." The reported surface temperature and dewpoint at a weather observation facility located about 50 statute miles from the accident site were 90 degrees F and 66 degrees F respectively. According to the pilot, the airplane was at 5,500 feet when the engine roughness occurred. According to "DOT/FAA/CT82/44 Publication; Light Aircraft Piston Engine Carburetor Ice Detector/Warning Device Sensitivity/Effectiveness" the probability of "[carburetor] icing at glide power and cruise power" exists in the aforementioned temperature/dewpoint conditions. According to the Cessna Aircraft Company Model 172 Information manual, Section 3, "A gradual loss of RPM and eventual engine roughness may result form the formation of carburetor ice. To clear the ice, apply full throttle and pull the carburetor heat knob full out until the engine runs smoothly; then remove carburetor heat and readjust the throttle." ## Aircraft - Registration: [N7954U](https://openairdocs.org/deregistered/N7954U-2013-07-23), registration cancelled 2013-07-23, S/N 17251954, built 1964 (OpenAirDocs) - Reported make and model: CESSNA 172 - Registry model: [Cessna 172F](https://openairdocs.org/model/cessna-172f) (registry code 2072414) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17251954 - Airframe hours: 1400 - Engines: CONTINENTAL O-300 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: R. A. Wilkinson/L. W. Brubaker - Registered owner: R.A. Wilkinson/L.W. Brubaker - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, April 11, 1993, 22 hours before - Departed: MGW, MORGANTOWN, PA - Destination: N97, CLEARFIELD, PA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; flight instructor, airline transport; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 16,110 total, 1,000 in this make and model, 15,610 as pilot in command, 40 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 66 °F - Altimeter: 30.00 inHg - Observed at: AGC, 50 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 19930706022629A](https://openairdocs.org/incident/19930706022629A), Jul 6, 1993: Cessna 172F, Normalsville, PA, Substantial damage. Lost power en route. Landed short of selected open field. Conditions good for carb ice. No engine anomalies. ## Other investigations on N7954U (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 DIA69F0175](https://openairdocs.org/ntsb/DIA69F0175), Mar 24, 1969: Cessna 172F (N7954U), Gaithersburg, MD, destroyed 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.