Individually Owned: 150,657
Corporate Owned: 137,281
Fresno Yosemite International Airport
Aircraft Accident/Incident Report
Fresno, California 93727
Friday, December 14, 2007 16:20 PST
NTSB Narrative Summary Released at Completion of Accident
The certified flight instructor (CFI) configured the helicopter for a practice emergency maneuver with the hydraulic system off. Upon disengaging the hydraulics, he immediately noticed that an abnormal force was required on the cyclic control to prevent the helicopter's nose from pitching up and to the left. He elected to continue the landing with the hydraulics off and began to slow the airspeed as the helicopter adjoined final approach. He was convinced that he would not be able to land the helicopter without it incurring damage due to the severe control restriction. He managed to complete a run-on landing without mishap by maintaining an airspeed of about 10 kts. When the helicopter came to rest, the pressure was released on the cyclic and the second pilot restored the hydraulics via the collective switch. Immediately thereafter, the cyclic began a hard over and displaced to the left against the CFI's leg. He attempted to center the cyclic with both hands, but he was unable to move the control. After 40 seconds the pressure released and the second pilot centered the cyclic with ease. The hydraulic servos were tested and a complete teardown of each servo was performed. The pressure testing of one of the servos revealed that the unlocking pressure was out of tolerance (too high). Upon disassembly of this servo, wear was observed on the conical surface of the locking finger and on the diameter in contact with the bearing. According to the servo manufacturer, the wear resulted in excessive friction in the bearing, which led to the high unlocking pressure.
NTSB Probable Cause Narrative
Malfunction of a hydraulic servo while on final approach due to excessive wear of the locking finger.
Event Information
| Type of Event | Incident |
| Event Date | 12/14/2007 |
| Event Day of the Week | Friday |
| Time of Event | 1620 |
| Event Time Zone | Pacific Standard Time |
| Event City | Fresno |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93727 |
| Event Date Year | 2007 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 364634N |
| Event Location Longitude | 1194305W |
| Event Location Airport | Fresno Yosemite International |
| Event Location Nearest Airport ID | FAT |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 336 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1555 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | FAT |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 12000 |
| Lowest Non-Ceiling Height | 12000 |
| Sky/Lowest/Cloud Conditions | Thin Overcast |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 10 |
| Dew Point at event time (in degress fahrenheit) | -1 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.24 |
| 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) | 24672 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Dec 23 2007 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Nov 24 2008 3:58PM |
| User who most recently changed record | coos |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N414HP |
| NTSB Number | LAX08IA042 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Eurocopter France |
| Aircraft Model | AS350 B3 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 3378 |
| Certified Max Gross Weight | 4961 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Nov 12 2007 12:00AM |
| Airframe hours since last inspection | 216 |
| Airframe Hours | 9019 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | California Highway Patrol |
| Aircraft Owner Street Address | 860 Stillwater Rd. |
| Aircraft Owner City | Sacramento |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 95605 |
| Operator is an individual? | No |
| Operator Name | California Highway Patrol |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 860 Stillwater Rd. |
| Operator City | Sacramento |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | 95605 |
| 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) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | FAT |
| Departure City | Fresno |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1600 |
| Departure Time Zone | PST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | FAT |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | Approach - VFR pattern - final approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 24 2008 3:47PM |
| User who most recently changed record | coos |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |