Individually Owned: 150,657
Corporate Owned: 137,281
Potomac Airfield Airport
Aircraft Accident/Incident Report
Friendly, Maryland 20744
Thursday, July 5, 2001 11:00 EDT
NTSB Narrative Summary Released at Completion of Accident
The pilot started the engine, taxied to runway 24, and performed a magneto check. No anomalies were observed, and he initiated a takeoff roll. However, the engine began to run rough, and the pilot aborted the takeoff. He then ran the engine at different RPM, and performed a second satisfactory magneto check. During the second takeoff roll, the engine ran rough again, and the pilot aborted the takeoff. The pilot then let the engine run for 5 minutes at different RPM, and it passed a third magneto check. On the third takeoff attempt, the engine "had good power," but as the airplane climbed above the trees, the engine lost all power and the pilot performed a forced landing into trees. Examination of the wreckage revealed that the right-side muffler baffling was mostly disintegrated, consistent with a baffling failure and subsequent blockage of the engine exhaust. The muffler baffling was required to be inspected for cracks and wear during the annual inspection of the airplane. The last annual inspection of the airplane was performed about 3 months and 2 weeks prior to the accident, and the airplane had accumulated approximately 28 hours of operation since that inspection.
NTSB Probable Cause Narrative
A baffling failure within the exhaust system. Factors were an inadequate annual inspection and the pilot's operation of the airplane with known deficiencies in equipment.
Event Information
| Type of Event | Accident |
| Event Date | 7/5/2001 |
| Event Day of the Week | Thursday |
| Time of Event | 1100 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Friendly |
| Event State | MARYLAND |
| Event Country | -- |
| Zipcode of the event site | 20744 |
| Event Date Year | 2001 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | Potomac Airfield |
| Event Location Nearest Airport ID | VKX |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 1 |
| Degrees magnetic from airport | 240 |
| Airport Elevation | 115 |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1051 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 340 |
| Weather Observation Facility ID | DCA |
| Elevation of weather observation facility | 15 |
| Distance of event from weather observation facility (units?) | 8 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 6000 |
| Sky/Lowest/Cloud Conditions | Few |
| 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) | 27 |
| Dew Point at event time (in degress fahrenheit) | 19 |
| Wind Direction (degrees magnetic) | 250 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 7 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.9 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 11531 |
| NTSB Notification Source | Eastern Region O |
| NTSB Notification Date | Jul 5 2001 12:00AM |
| NTSB Notification Time | 1200 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Feb 20 2002 1:46PM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Dulles, VA |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N6647M |
| NTSB Number | NYC01LA164 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Stinson |
| Aircraft Model | 108-3 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 108-4647 |
| Certified Max Gross Weight | 2400 |
| 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 | Mar 22 2001 12:00AM |
| Airframe hours since last inspection | 28 |
| Airframe Hours | 1409 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Alan L. Williams |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Alexandria |
| Aircraft Owner State | VA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 22306 |
| 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 | Yes |
| Departure Airport Code | VKX |
| Departure City | Friendly |
| Departure State | MD |
| Departure Country | USA |
| Departure Time | 1100 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | W32 |
| Destination City | Clinton |
| Destination State | MD |
| Destination Country | USA |
| Specific Phase of Flight | Takeoff - initial climb |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Jan 21 2002 11:44AM |
| User who most recently changed record | PEAR |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 24 |
| Runway Length | 2665 |
| Runway Width | 40 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |