Eurocopter France AS350 B3 incident near Fresno, California, December 15, 2007
On December 15, 2007, a Eurocopter France AS350 B3 (helicopter), registered N414HP, was involved in an incident near Fresno, California (Fresno Yosemite International airport). It was a public-use flight (state) under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Malfunction of a hydraulic servo while on final approach due to excessive wear of the locking finger.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 15, 2007
- Place
- Fresno, California · Fresno Yosemite International · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter France AS350 B3 · all AS350 B3s on the register
- Registration
- N414HP · no longer on the register · serial 3378
- Damage
- Not recorded
- Flight
- Public-use flight (state) · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,669 hours in all; 2,877 in this make and model; 101 in the last 90 days; 35 in the last 30 days; 4,332 as pilot in command; 871 on instruments
- Last flight review: December 11, 2006
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Pilot
- Certificate: commercial pilot
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 188 hours in all; 31 in this make and model; 28 in the last 90 days; 14 in the last 30 days; 155 as pilot in command
- Last flight review: November 19, 2007
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 9,019 hours
- Last inspection: 100-hour inspection, November 12, 2007; 216 hours since
- Maximum gross weight: 4,961 lb
- Seats: 2
- Landing gear: fixed
- Engine: Turbo Mecca Arriel 2B (turboshaft); 0 hours total
The flight
- Departed from: FAT Fresno CA
- Destination: FAT
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: at 3 knots
- Visibility: 10 statute miles
- Sky: overcast at 12,000 ft; ovct at 12,000 ft
- Temperature: 50°F (10°C), dew point 30°F (-1°C)
- Altimeter: 30.23 inHg
- Observation at 11:55 pm from FAT
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.