Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Marinette, Wisconsin 54143
Tuesady, June 24, 2008 8:45 CDT
NTSB Narrative Summary Released at Completion of Accident
The purpose of the test flight was to determine performance characteristics of the manufacturing company's helicopter at maximum gross weight and maximum aft center of gravity (CG). The helicopter was in a climb at 95 knots indicated airspeed and the pilot had just applied power when he and his passenger noticed a moderate to severe vibration which lasted a few seconds. The pilot reduced power and it went away. The pilot then reduced power to around 55 psi torque at about 90 knots indicated airspeed and trimmed forward to do a reverse trim check while trying to maintain torque and altitude with slightly heavy collective. Then there was a shudder, followed almost instantly by a loud bang and crunching sound, before the nose pitched down and the helicopter turned 120 to 150 degrees to the left. The pilot regained control, selected a field, and proceeded to make an emergency landing. As he began his landing, he noted he no longer had pedal control. The pilot added throttle, managed to bring the nose around, and landed the helicopter straight ahead.
Postaccident inspection of the helicopter revealed that the tailcone was buckled in front of the horizontal stabilizer, displacing the stabilizer trailing edge downward and causing slack in the tail rotor control cables. No other preimpact anomalies were found with the helicopter or its systems. Further examination determined that before the flight they had put more fuel in the helicopter than was indicated on the fuel gauges. This resulted in the helicopter being operated at a higher-than-maximum gross weight, at its aft most CG, and reduced the helicopter's never-to-exceed airspeed (Vne) to 87 knots indicated airspeed. When the pilot exceeded Vne during the climb, structural damage occurred.
NTSB Probable Cause Narrative
The pilot inadvertently operating the helicopter at a gross weight greater than its maximum allowable operating weight, and flying the helicopter at an airspeed greater than the never-to-exceed speed for the helicopter’s gross weight condition, resulting in structural damage to the tailcone.
Event Information
| Type of Event | Accident |
| Event Date | 6/24/2008 |
| Event Day of the Week | Tuesday |
| Time of Event | 845 |
| Event Time Zone | Central Daylight Time |
| Event City | MARINETTE |
| Event State | WISCONSIN |
| Event Country | -- |
| Zipcode of the event site | 54143 |
| Event Date Year | 2008 |
| Event Date Month | 6 |
| 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 | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 755 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 360 |
| Weather Observation Facility ID | KMNM |
| Elevation of weather observation facility | 609 |
| Distance of event from weather observation facility (units?) | 5 |
| 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) | 17 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 200 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.16 |
| 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) | 27163 |
| NTSB Notification Source | ENSTROM HELICOPTER |
| NTSB Notification Date | Jun 24 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | May 2 2011 12:56PM |
| User who most recently changed record | bowl |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | MILWAUKEE FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N480PD |
| NTSB Number | CHI08FA172 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | ENSTROM HELICOPTER CORP |
| Aircraft Model | 480B |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 5080 |
| Certified Max Gross Weight | 3000 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 3 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Mar 28 2008 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 707 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | ENSTROM HELICOPTER CORP |
| Aircraft Owner Street Address | 2209 22ND ST |
| Aircraft Owner City | MENOMINEE |
| Aircraft Owner State | MI |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 49858-3515 |
| Operator is an individual? | No |
| Operator Name | ENSTROM HELICOPTER CORPORATION |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 2209 22ND STREET |
| Operator City | MENOMINEE |
| Operator State | MI |
| Operator Country | USA |
| Operator Zip code | 49858 |
| 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) | Flight Test |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | MNM |
| Departure City | MENOMINEE |
| Departure State | MI |
| Departure Country | USA |
| Departure Time | 0 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | Maneuvering |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | May 19 2011 12:58PM |
| User who most recently changed record | broda |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |