Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Brookfield, Missouri 64628
Monday, April 30, 2007 16:43 CDT
NTSB Narrative Summary Released at Completion of Accident
he pilot reported that the engine was "operating normally" as he was flying at 6,500 feet mean sea level when the "engine blew up." He elected to execute a gear up forced landing to a corn field about two miles from the airport, but the airplane impacted a ditch during the emergency landing. The engine teardown inspection revealed a hole in the crankcase approximately 3 inches by 3 inches above the number 4 cylinder, which included the 11 and 1 o'clock deck studs. The number 4 cylinder had separated from the crankcase and the number 4 connecting rod was not attached to the number 4 crankshaft pin. The number 4 connecting rod and rod cap exhibited signatures that were consistent with an overload event that deformed and/or sheared the threads on the nuts and bolts. Cylinder number 4 deck stud nuts 6, 7, and 8 were reported missing from the engine at the accident scene, and subsequently found inside the engine cowling of the aircraft. Cylinder number 4 deck studs 6, 7, and 8 were securely attached to the engine crankcase and the threads were clean and undamaged. The 2 o'clock cylinder deck stud was fractured and missing. The remaining deck studs and thru-bolts all exhibited ductile fractures indicative of tensile overload. The other five cylinders' thru-bolt and deck stud break-away torque measurements were recorded for each thru-bolt and deck stud. The inspection revealed that numerous thru-bolts and studs had break-away torque values that did not comply with the manufacturer's limitations. The aircraft engine's logbook indicated that the engine received an annual maintenance inspection on February 16, 2005. The engine logbook entry stated, "Removed and overhauled all 6 cylinders. Installed new rings, ground valves, cleaned and gapped spark plugs." The tach time indicated 5380.5 hours at the time of the annual inspection. At the time of the accident, the tach time was 5,662.24 hours, 281.74 hours since the cylinders had been replaced.
NTSB Probable Cause Narrative
Improper maintenance by maintenance personnel by not properly torquing cylinder thru-bolts. The loose stud nuts which resulted in the separation of the cylinder and the crop and ditch were factors.
Event Information
| Type of Event | Accident |
| Event Date | 4/30/2007 |
| Event Day of the Week | Monday |
| Time of Event | 1643 |
| Event Time Zone | Central Daylight Time |
| Event City | Brookfield |
| Event State | MISSOURI |
| Event Country | -- |
| Zipcode of the event site | 64628 |
| Event Date Year | 2007 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 394612N |
| Event Location Longitude | 0930045W |
| 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 | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1655 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 230 |
| Weather Observation Facility ID | IRK |
| Elevation of weather observation facility | 966 |
| Distance of event from weather observation facility (units?) | 35 |
| Time Zone of the weather observation | CDT |
| 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) | 28 |
| Dew Point at event time (in degress fahrenheit) | 11 |
| Wind Direction (degrees magnetic) | 210 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 16 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 22 |
| Altimeter Setting at event time (in. Hg) | 29.86 |
| 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) | 23046 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Apr 30 2007 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Feb 28 2008 3:59PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Kansas City, FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N8820M |
| NTSB Number | CHI07LA127 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Unknown |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Beech |
| Aircraft Model | S35 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | D-7331 |
| Certified Max Gross Weight | 3300 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | May 1 2006 12:00AM |
| Airframe hours since last inspection | 137 |
| Airframe Hours | 5662 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Marc Incorporated |
| Aircraft Owner Street Address | 44 Crossgates Drive |
| Aircraft Owner City | Brandon |
| Aircraft Owner State | MS |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 39042 |
| 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 | -- |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | M16 |
| Departure City | Raymond |
| Departure State | MS |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | FOD |
| Destination City | Fort Dodge |
| Destination State | IA |
| Destination Country | USA |
| Specific Phase of Flight | Emergency landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 5 2008 2:30PM |
| User who most recently changed record | SULP |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |