- Date
- June 2, 1994, 12:46 local (19:46 UTC)
- Place
- Chino, CA
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N14412Bell 47D-1
- Weather
- Visual (VMC) · Day
- Status
- Completed · report November 14, 1994
- Report
- Approved by Office Director
- FAA report
- 19940602013379A
- Case key
- 28756
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
loss of aircraft control due to the pilot's failure to correctly configure the hydraulic system prior to takeoff.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The pilot reported that she lifted into a hover in preparation for takeoff and the helicopter began a pilot inducted oscillation due to heavy cyclic control forces. The pilot stated that she overcompensated on the controls and the helicopter rolled over. The pilot reported that during the run-up procedure she disengaged the hydraulic system to check the rotor tip path plane and forgot to reengage the system prior to lifting into a hover. The pilot said there was no mechanical malfunction or failure of any system.
Factual narrative
On June 2, 1994, at 1246 Pacific daylight time, a Bell 47D-1 helicopter, N14412, rolled over during hover at the Chino, California, airport. The aircraft was in a hover in preparation for takeoff from a helipad on the airport. The helicopter was owned and operated by Mike Zemlock Helicopters of Chino and was rented by the pilot for a local area personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft incurred substantial damage. The certificated private pilot, the sole occupant, was not injured. The flight was originating at the time of the occurrence.
In a telephone interview, the pilot reported that she lifted into a hover in preparation for takeoff and the helicopter began a pilot inducted oscillation due to heavy cyclic control forces. The pilot stated that she overcompensated on the controls and the helicopter rolled over. The pilot reported that during the run-up procedure she disengaged the hydraulic system to check the rotor tip path plane and forgot to reengage the system prior to lifting into a hover. The pilot said there was no mechanical malfunction or failure of any system.
Aircraft
- Registration
- N14412
- Reported as
- Bell 47D-1
- Category
- Helicopter
- Serial number
- 996
- Airframe hours
- 7,661
- Engine
- Franklin 6V4-200-C32, 200 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Zemlock, Mike, doing business as Zemlock Helicopter Service
- Registered owner
- Zemlock, Mike
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · May 6, 1994 · 61 hours before
- Airport
- CNO · Chino
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 47
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 1,619 total · 216 in this make and model · 1,428 as pilot in command
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 240° at 5 knots
- Visibility
- 6 statute miles
- Temperature
- 81 °F
- Altimeter
- 29.00 inHg
- Observed at
- CNO
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.