Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
West Plains, Missouri 65789
Friday, March 8, 2002 10:05 CST
NTSB Narrative Summary Released at Completion of Accident
The airplane sustained substantial damage during a forced landing to a field after a total loss of engine power. The pilot reported he was cruising at 3,000 feet msl when he heard a loud bang from the engine, followed almost immediately by smoke from beneath the left side panel and excessive vibration from the engine. The engine lost power and the pilot executed a forced landing. During landing roll out, the nose wheel struck a rock and the nose gear collapsed. An inspection of the engine revealed that a connecting rod had punched a hole in the engine case. The number 2 piston rod, rod bearing, and rod journal were discolored and exhibited heat distress. The crankshaft was broken in two pieces at the number 2 cheek. A fatigue fracture was observed on the fracture surfaces of the number 2 cheek. The engine was originally a 230 horsepower Continental O-470-R that was converted to a 270 horsepower O-470-50, as a result of Supplemental Type Certificate (STC) #SE4985NM. This STC required the cylinders to be replaced with the same cylinders and pistons used on Continental O-520 engines. The crankshaft, forging number 539664, S/N S401, and heat code E99, referred to as a "wide-rod" crankshaft, was manufactured in the 1960's and was originally used on Continental Motors O-470 and IO-470 engines. The crankshaft had not been replaced since the STC conversion on December 23, 1994. It had accumulated 1,259.0 hours since the STC conversion. The engine teardown revealed that the pistons installed on the engine were 8.5 to 1 compression pistons used on normally aspirated Continental O-520 engines. The P. Ponk Aviation STC SE4985NM specifies that the 7.5 to 1 compression pistons are the proper pistons to use in the engine conversion. On September 24, 2002, P. PONK AVIATION, issued a Service Information Letter, SIL 002, that stated, "Use of the "wide-rod" crankshaft with any piston higher than the 7.5 to 1 compression ratio and a maximum rpm above 2700 is not authorized by our STC and could result in engine failure. Our testing did not exceed the above parameters, and we do not condone or support installation of the higher compression pistons." No logbook entries indicated any of the pistons had been changed since the engine was converted to an O-470-50, on December 23, 1994, and only the # 3 cylinder was changed on April 15, 2000, due to low compression. The engine build-up records that documented what parts were installed on the engine during the STC conversion no longer existed.
NTSB Probable Cause Narrative
The engine failure due to the fatigue fracture of the crankshaft which resulted from the installation of improper pistons during an STC'd engine conversion by other maintenance personnel. Additional factors included the unsuitable terrain encountered by the pilot during the forced landing.
Event Information
| Type of Event | Accident |
| Event Date | 3/8/2002 |
| Event Day of the Week | Friday |
| Time of Event | 1005 |
| Event Time Zone | Central Standard Time |
| Event City | West Plains |
| Event State | MISSOURI |
| Event Country | -- |
| Zipcode of the event site | 65789 |
| Event Date Year | 2002 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1000 Central Standard Time |
| Direction of event from weather observation facility (degrees) | 314 |
| Weather Observation Facility ID | UNO |
| Elevation of weather observation facility | 1228 |
| Distance of event from weather observation facility (units?) | 14 |
| Time Zone of the weather observation | CST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 16 |
| Dew Point at event time (in degress fahrenheit) | 8 |
| Wind Direction (degrees magnetic) | 170 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.99 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 13752 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Mar 8 2002 12:00AM |
| NTSB Notification Time | 1506 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Aug 26 2003 8:17AM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | FAA St. Louis FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N64AE |
| NTSB Number | CHI02LA087 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Cessna |
| Aircraft Model | 182H |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 18255970 |
| Certified Max Gross Weight | 2800 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Feb 21 2002 12:00AM |
| Airframe hours since last inspection | 6 |
| Airframe Hours | 6052 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Air Evac EMS |
| Aircraft Owner Street Address | 1488 w. 8th St. |
| Aircraft Owner City | West Plains |
| Aircraft Owner State | MO |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 65789 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | EVAC |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Business |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | UNO |
| Departure City | West Plains |
| Departure State | MO |
| Departure Country | USA |
| Departure Time | 950 |
| Departure Time Zone | CST |
| Destination Same as Local Flt | -- |
| Destination Airport Code | JBR |
| Destination City | Jonesboro |
| Destination State | AR |
| Destination Country | USA |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Jun 24 2003 10:06AM |
| User who most recently changed record | SULP |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | -- |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |