Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Vermillion 44, -- 00000
Friday, May 4, 2001 16:16 CDT
NTSB Narrative Summary Released at Completion of Accident
While in cruise flight, the pilot reported that a "slight vibration became noticeable." After a few minutes, the vibration became more pronounced, and was accompanied by a noise. During an attempted precautionary landing to an offshore platform, the vibration and noise level increased again, and total engine power was lost. The pilot then initiated an autorotation to the water, deployed the skid floats, and landed safely. While the helicopter was being towed in the water, the helicopter rolled inverted. Examination of the helicopter after recovery revealed that the KAflex engine-to-transmission driveshaft was fractured, and the forward tail rotor driveshaft segment was separated. Examination of the KAflex driveshaft revealed fatigue fractures that originated from a bolt hole in the first flex frame of the coupling at the transmission end of the shaft and fatigue fractures in the end fitting at the transmission end. The primary fracture was a fatigue crack that occurred in a bolt hole where a bolt joined the first flex frame to the center flex frame. The driveshaft was determined to be manufactured within engineering specifications. The fractured tail rotor driveshaft showed evidence of torsional overstress. The KAflex driveshaft coupling had a total time of 2,114.2 hours and an airworthiness life limit of 5,000 hours. Following the accident, the manufacturer issued a service bulletin introducing a new KAflex driveshaft with a 1,250-hour overhaul interval.
NTSB Probable Cause Narrative
Failure of the engine-to-transmission driveshaft coupling due to fatigue.
Event Information
| Type of Event | Accident |
| Event Date | 5/4/2001 |
| Event Day of the Week | Friday |
| Time of Event | 1616 |
| Event Time Zone | Central Daylight Time |
| Event City | Vermillion 44 |
| Event State | GULF OF MEXICO |
| Event Country | -- |
| Zipcode of the event site | 00000 |
| Event Date Year | 2001 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 292600N |
| Event Location Longitude | 0923000W |
| 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 | Partial - limited by pilot |
| Investigator's weather source | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| 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) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 13057 |
| NTSB Notification Source | FAA Communications Center |
| NTSB Notification Date | May 4 2001 12:00AM |
| NTSB Notification Time | 1948 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Apr 29 2003 4:26PM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Baton Rouge, LA |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N917AL |
| NTSB Number | FTW01FA115 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bell |
| Aircraft Model | 407 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 53381 |
| Certified Max Gross Weight | 5250 |
| Aircraft Category | Helicopter |
| 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 | 7 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Apr 1 2001 12:00AM |
| Airframe hours since last inspection | 139 |
| Airframe Hours | 2114.2 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Air Logistics L.L.C. |
| Aircraft Owner Street Address | 4605 Industrial Dr. |
| Aircraft Owner City | New Iberia |
| Aircraft Owner State | LA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 70560 |
| 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 | ALGL |
| Owner has at least one certificate | -- |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | External Load |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Non-scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger/Cargo |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | 368 |
| Departure City | HI-338 |
| Departure State | GM |
| Departure Country | USA |
| Departure Time | 1535 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | 7RA |
| Destination City | Intercoastal |
| Destination State | LA |
| Destination Country | USA |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | Yes |
| Date of most recent change to record | Feb 10 2003 9:01AM |
| User who most recently changed record | CASH |
| 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 | -- |