LAX94LA220

NTSB accident investigation · Robinson R22-B · Stockton, CA · May 19, 1994

Accident · Minor injuriesLimited investigationFinal report
Date
May 19, 1994, 07:20 local (14:20 UTC)
Place
Stockton, CA
Injuries
1 minor, 1 uninjured
Phase of flight
Standing
Aircraft
N140PHRobinson R22-BN2314ZRobinson R22-B
Weather
Visual (VMC) · Day
Status
Completed · report December 19, 1994
Report
Approved by Office Director
Case key
28741

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

A failure of the pilot-in-command of a landing helicopter to maintain sufficient clearance from a second helicopter.

The failure of the pilot-in-command of the landing helicopter to maintain sufficient clearance from a second helicopter.

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.

Collision between aircraft (other than midair)Standing - idling rotors
Object - aircraft parked/standing
Clearance - not maintainedPilot of other aircraftCause
Collision between aircraft (other than midair)Standing - engine(s) operating
Object - aircraft parked/standing
Clearance - not maintainedPilot in commandCause

Analysis

The helicopter was being utilized to dry cherry trees in a local orchard and landed for fuel at a private airstrip. The pilot had reduced collective pitch to zero and the rotor blades were still turning at flight idle. A sister helicopter from the same operator landed to the right of the idling helicopter to refuel. When the pilot of the second helicopter reduced collective pitch to zero, the rotor blades meshed with those of the first helicopter.

The helicopter was being utilized to dry cherry trees in a local orchard and landed for fuel at a private airstrip. The pilot had reduced collective pitch to zero and the rotor blades were still turning at flight idle. A sister helicopter from the same operator landed to the right of the idling helicopter to refuel. When the pilot of the second helicopter reduced collective pitch to zero, the rotor blades meshed with those of the first helicopter.

Factual narrative

On May 19, 1994, about 0720 hours Pacific daylight time, a Robinson R22-B helicopter, N140PH, collided with a second Robinson R22-B, N2314Z, while on the ground at a private airstrip, about 10 miles north of Stockton, California. The two helicopters were being operated as a visual flight rules (VFR) flight to dry cherry trees in the local area when the accident occurred. The helicopters, operated by Sunrise Helicopters Inc., Stockton, California, both received substantial damage. The pilot of N140PH, a certificated commercial pilot, received minor injuries. The pilot of N2314Z, also a certificated commercial pilot, was not injured. Visual meteorological conditions prevailed. The flight originated at Stockton Metropolitan Airport, about 0540 hours.

The pilots reported that after terminating the tree drying operation over a local orchard, both aircraft proceeded to Wallom Field, a private airstrip, to refuel. The pilot of N140PH landed near the refueling point and had reduced the engine power to idle. The rotor blades were still turning. The pilot of N2314Z landed to the right side of the first aircraft. After the landing gear skids had touched down, the pilot lowered the collective pitch control to full down. As the second helicopter's rotor blades reached flat pitch, they meshed with those of N140PH. The resulting action caused both helicopters to pivot on the ground. Both aircraft received damage to the main rotor blades, mast and transmission, and tail boom.

On May 19, 1994, about 0720 hours Pacific daylight time, a Robinson R22-B helicopter, N140PH, collided with a second Robinson R22-B, N2314Z, while on the ground at a private airstrip, about 10 miles north of Stockton, California. The two helicopters were being operated as a visual flight rules (VFR) flight to dry cherry trees in the local area when the accident occurred. The helicopters, operated by Sunrise Helicopters Inc., Stockton, California, both received substantial damage. The pilot of N140PH, a certificated commercial pilot, received minor injuries. The pilot of N2314Z, also a certificated commercial pilot, was not injured. Visual meteorological conditions prevailed. The flight originated at Stockton Metropolitan Airport, about 0540 hours.

The pilots reported that after terminating the tree drying operation over a local orchard, both aircraft proceeded to Wallom Field, a private airstrip, to refuel. The pilot of N140PH landed near the refueling point and had reduced the engine power to idle. The rotor blades were still turning. The pilot of N2314Z landed to the right side of the first aircraft. After the landing gear skids had touched down, the pilot lowered the collective pitch control to full down. As the second helicopter's rotor blades reached flat pitch, they meshed with those of N140PH. Both helicopters pivoted on the ground and both aircraft received damage to the main rotor blades, mast and transmission, and tail boom.

Aircraft · 2

Registration
N140PH
Reported as
Robinson R22-B
Category
Helicopter
Serial number
1408
Airframe hours
2,809
Engine
Lycoming O-320-B2C, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Other work use · Part 91
Operator
David L. Heath, doing business as Sunrise Helicopters
Registered owner
David L. Heath
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · May 12, 1995 · 23 hours before
Airport
Wallom Field

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.

Registration
N2314Z
Reported as
Robinson R22-B
Category
Helicopter
Serial number
1995
Airframe hours
1,990
Engine
Lycoming O-320-B2C, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Other work use · Part 91
Operator
David L. Heath, doing business as Sunrise Helicopters
Registered owner
David L. Heath
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · March 22, 1994 · 28 hours before
Departed
SCK
Destination
SCK
Airport
Wallom Field

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot, aircraft N140PH
Age
37
Certificate
Commercial
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Right
Flight hours
1,165 total · 1,162 in this make and model · 1,000 as pilot in command · 100 in the last 90 days · 30 in the last 30 days · 6 in the last 24 hours
Role
Pilot, aircraft N2314Z
Age
56
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Right
Flight hours
3,059 total · 1,636 in this make and model · 2,778 as pilot in command · 29 in the last 90 days · 10 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
220° at 10 knots
Visibility
20 statute miles
Lowest ceiling
4,000 ft overcast
Temperature
54 °F, dew point 46 °F
Altimeter
30.00 inHg
Observed at
SCK, 10 nm away

FAA reports on this event · 2

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.