Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Agnos, Arkansas 72513
Friday, November 6, 2009 10:05 CST
NTSB Narrative Summary Released at Completion of Accident
Flight track data recovered from an onboard global positioning system, and a subsequent performance study depicted the accident airplane flying between the altitudes of 2,500 and 3,500 feet at airspeeds between 60 and 108 knots calibrated airspeed (KCAS). The calculated bank angle for the entire flight never exceeded 30 degrees and at the time of the accident, the airplane was climbing at 500 feet per minute through 2,800 feet and had accelerated to 100 KCAS. The estimated angle of attack was about 3 degrees during the last minute of the flight. There was no evidence of excessive airspeed or maneuvers that would lead to a structural overload and subsequent breakup. The wreckage was spread over 600 feet. An examination of the airplane wreckage revealed compression buckling of the upper and lower caps of both rear spars and upward and downward bending of both wings. The upward and downward movement, twisting, and flexing of the airplane wing surface was consistent with the occurrence of aerodynamic flutter. The structural loading at the wing roots were further increased as the trailing edges of the outboard sections moved up and down. Ultimately both wings failed in down bending at the root. The ailerons did not have counterbalances that offer direct protection from aerodynamic flutter. Aerodynamic flutter can occur when there is insufficient stiffness in the structure or the flight controls are not mass balanced. Less stiff structure can be protected to higher airspeeds with the use of counterbalances on the flight controls. In addition, damage was noted on the flap assemblies consistent with over travel in the upward direction. An examination of the engine revealed no anomalies.
The accident pilot was experienced in the accident airplane and had built the airplane from a kit. Medical and pathological examination of the pilot revealed the cause of death as impact related and no medical or toxicological issues that would have precluded him from operating the airplane in a safe manner prior to the accident.
NTSB Probable Cause Narrative
The in-flight separation of both wings due to aileron flutter. The aileron flutter was the result of inadequate wing stiffness and the lack of aileron counterbalances.
Event Information
| Type of Event | Accident |
| Event Date | 11/6/2009 |
| Event Day of the Week | Friday |
| Time of Event | 1005 |
| Event Time Zone | Central Standard Time |
| Event City | Agnos |
| Event State | ARKANSAS |
| Event Country | -- |
| Zipcode of the event site | 72513 |
| Event Date Year | 2009 |
| Event Date Month | 11 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 361519N |
| Event Location Longitude | 0914135W |
| 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 | 953 Central Standard Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | KBPK |
| Elevation of weather observation facility | 928 |
| Distance of event from weather observation facility (units?) | 38 |
| Time Zone of the weather observation | CST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 3400 |
| 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) | 9 |
| Air Temperature at event time (in degrees celsius) | 18 |
| Dew Point at event time (in degress fahrenheit) | 10 |
| Wind Direction (degrees magnetic) | 180 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.19 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | 1 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 27762 |
| NTSB Notification Source | FAA ASW ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Feb 2 2011 8:20AM |
| User who most recently changed record | andj |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N538CJ |
| NTSB Number | CEN10FA042 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Destroyed |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | ZENITH AIRCRAFT CO |
| Aircraft Model | ZODIAC 601 XL |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 6-6528 |
| Certified Max Gross Weight | 1320 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Unknown |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | CUMMINGS CHARLES |
| Aircraft Owner Street Address | PO BOX 208 |
| Aircraft Owner City | NORTH AURORA |
| Aircraft Owner State | IL |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 60542-0208 |
| Operator is an individual? | No |
| Operator Name | CUMMINGS CHARLES |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | PO BOX 208 |
| Operator City | NORTH AURORA |
| Operator State | IL |
| Operator Country | USA |
| Operator Zip code | 60542-0208 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| 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 | KCVK |
| Departure City | Ash Flat |
| Departure State | AR |
| Departure Country | USA |
| Departure Time | 848 |
| Departure Time Zone | CST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | KCVK |
| Destination City | Ash Flat |
| Destination State | AR |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 2 2011 8:20AM |
| User who most recently changed record | andj |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |