Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Morgan Hill, California 95037
Friday, July 19, 1996 10:34 PDT
NTSB Narrative Summary Released at Completion of Accident
The pilot reported that the helicopter was in cruise flight at 1,000 feet agl when he noticed that both the engine and main rotor were at 110 percent on the dual tachometer. He then entered an autorotation because he believed the engine might quit. The student stated that at touchdown the helicopter had a nose low attitude with some forward speed remaining and the skids dug into the ground, rolling the helicopter over. Through a translator, the pilot reported that the engine/main rotor governor was not working properly. Robinson Helicopter Company reported that the governor unit senses main rotor speed through a sending unit on the engine to transmission shaft. An electronic computer maintains the speed within the normal operating range through a servo motor which actuates the throttle on the collective by means of a clutch assembly. The unit can be turned off by a toggle switch on the collective control, and can be overridden by twisting the throttle. The entire governor assembly, including the speed sensing unit, computer, servo, clutch, and collective/throttle were removed from the helicopter and taken to Robinson Helicopter Company by a Safety Board investigator. All components of the unit were functionally tested and performed within factory new unit acceptance criteria.
NTSB Probable Cause Narrative
The student's improper reaction to an engine/main rotor overspeed condition, and his failure to achieve the proper zero airspeed nose high attitude during a touchdown from an autorotation.
Event Information
| Type of Event | Accident |
| Event Date | 7/19/1996 |
| Event Day of the Week | Friday |
| Time of Event | 1034 |
| Event Time Zone | Pacific Daylight Time |
| Event City | MORGAN HILL |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 95037 |
| Event Date Year | 1996 |
| Event Date Month | 7 |
| 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 | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 946 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 300 |
| Weather Observation Facility ID | SJC |
| Elevation of weather observation facility | 56 |
| Distance of event from weather observation facility (units?) | 22 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 2000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 20 |
| Dew Point at event time (in degress fahrenheit) | 10 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Light and Variable |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 809 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 19 1996 12:00AM |
| NTSB Notification Time | 1130 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 10:12AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N730SH |
| NTSB Number | LAX96LA277 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Robinson |
| Aircraft Model | R22B |
| Aircraft Series Identifier | R22B |
| Aircraft Serial Number | 1730 |
| 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 | Jul 8 1996 12:00AM |
| Airframe hours since last inspection | 50 |
| Airframe Hours | 3951 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | TAKAI HIROYASU |
| Aircraft Owner Street Address | 2575 ROBERT FOWLER WAY |
| Aircraft Owner City | SAN JOSE |
| Aircraft Owner State | CA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 95148 |
| Operator is an individual? | -- |
| 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? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| 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 | No |
| Departure Point Same as Event | No |
| Departure Airport Code | Q99 |
| Departure City | SAN MARTIN |
| Departure State | CA |
| Departure Country | |
| Departure Time | 1020 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | RHV |
| Destination City | SAN JOSE |
| Destination State | CA |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:34AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |