Individually Owned: 151,845
Corporate Owned: 143,699
East Troy Municipal Airport
Aircraft Accident/Incident Report
East Troy, Wisconsin 53120
Saturday, January 5, 2002 9:00 CST
NTSB Narrative Summary Released at Completion of Accident
The helicopter sustained substantial damage when the left, rear landing skid cross tube collapsed during landing. The CFI reported they taxied to the parallel taxiway of runway 26 to practice hovering autorotations. He reported, "I demonstrated three of them and then [the pilot receiving instruction] performed two. About a second or so after the touchdown on [the pilot receiving instruction's] 2nd hovering auto, the left skid collapsed and the helicopter slowly and gently rolled onto it's left side. The main rotor blades made contact with the ground and came to a stop." He reported, "All hovering autos were performed into the wind from a stabilized hover of 3-5 feet agl. All were terminated with the skids close to parallel with the taxiway without any hard landings." The cross tubes had about 1,500 hours since the last major overhaul. The aircraft had flown 9.6 hours since the last 100 hour inspection. An A&P mechanic reported he had examined the cross tubes during the 100 hour inspection. He reported the height of the tail measured 35 inches. The manufacturer's criteria for replacing the cross tubes is a measured tail height of 34 inches or less. The mating fractures from the left sides of the front and rear landing skid cross tubes were sent to the National Transportation Safety Board's (NTSB) Materials Laboratory for examination. The inspection revealed the following: "Magnified optical examinations of both fractures revealed features typical of overstress separations in aluminum tubes. In addition, the orientations and paths of the fractures along with associated deformation patterns were consistent with large upward loads on the skid ends of both tubes at the time of fracture. In addition to the local deformation at the fractures both tubes also displayed large radius upward bends along most of their lengths. No indications of preexisting fatigue or corrosion were apparent on the fractures or in the surrounding areas."
NTSB Probable Cause Narrative
The pilot receiving instruction failed to maintain the proper descent rate.
Event Information
| Type of Event | Accident |
| Event Date | 1/5/2002 |
| Event Day of the Week | Saturday |
| Time of Event | 900 |
| Event Time Zone | Central Standard Time |
| Event City | East Troy |
| Event State | WISCONSIN |
| Event Country | -- |
| Zipcode of the event site | 53120 |
| Event Date Year | 2002 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | East Troy Municipal Airport |
| Event Location Nearest Airport ID | 57C |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | 860 |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 845 Central Standard Time |
| Direction of event from weather observation facility (degrees) | 20 |
| Weather Observation Facility ID | UES |
| Elevation of weather observation facility | 911 |
| Distance of event from weather observation facility (units?) | 15 |
| Time Zone of the weather observation | CST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 9000 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 7 |
| Air Temperature at event time (in degrees celsius) | -1 |
| Dew Point at event time (in degress fahrenheit) | -3 |
| Wind Direction (degrees magnetic) | 250 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.89 |
| 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) | 12167 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jan 5 2002 12:00AM |
| NTSB Notification Time | 1154 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Aug 28 2002 10:10AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | FAA-Milwaukee FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N215WW |
| NTSB Number | CHI02LA061 |
| 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 | Robinson |
| Aircraft Model | R22 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 0930 |
| Certified Max Gross Weight | 1370 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Jan 3 2002 12:00AM |
| Airframe hours since last inspection | 10 |
| Airframe Hours | 7510 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | WW Helicopters |
| Aircraft Owner Street Address | 2085 Highway L |
| Aircraft Owner City | East Troy |
| Aircraft Owner State | WI |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 53120 |
| 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) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | 57C |
| Departure City | East Troy |
| Departure State | WI |
| Departure Country | USA |
| Departure Time | 820 |
| Departure Time Zone | CST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Landing |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Aug 5 2002 6:27PM |
| User who most recently changed record | SULP |
| 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 | -- |