BFO94LA100

NTSB accident investigation · Robinson R-22 · Raynham, MA · June 15, 1994

Accident · No injuriesLimited investigationFinal report
Date
June 15, 1994, 12:45 local (16:45 UTC)
Place
Raynham, MA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N8029ZRobinson R-22
Weather
Visual (VMC) · Day
Status
Completed · report April 5, 1995
Report
Approved by Office Director
FAA report
19940615047709A
Case key
8933

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

Failure of the number four cylinder piston rings.

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.

Loss of engine power(total) - mech failure/malfCruise - normal
Engine assembly,ring - failure,total
Forced landingDescent - emergency
Terrain condition - none suitable

Analysis

While in cruise flight at 500 feet above the ground, the engine had a partial loss of power. The pilot stated that he noticed a rapid rise in the oil temperature, cylinder head temperature, and manifold pressure. He stated the rpm's began to decrease so he initiated an emergency descent to land. He stated about 100 feet above the ground, total power loss occurred and he did an autorotation landing. The pilot stated that due to irregular terrain at the landing site, the main rotor blades flexed down and contacted the tail boom. The examination of the engine revealed that there were metal shavings throughout the engine and the number four piston rings were broken.

Factual narrative

On June 15, 1994, about 1230 eastern daylight time, a Robinson R- 22, N8029Z, lost total engine power while in cruise flight. An emergency landing was made and the helicopter was substantially damaged during the landing. The pilot was not injured. Visual meteorological conditions prevailed at the time and location of the accident. The business flight was conducted under 14 CFR Part 91.

The pilot stated that the helicopter was about 500 feet above the ground when he noticed a rapid rise in the oil temperature, cylinder head temperature, and manifold pressure. He stated that the revolutions per minute (RPM) were decreasing. He stated he started to make an emergency descent and at 100 feet above the ground the engine lost total power. The pilot stated, "I initiated auto rotation at that point. Irregular terrain at the landing site caused the main rotor blades to flex down and contact the tail boom."

Examination of the helicopter at the accident site revealed the tail boom was severed about 33 inches in front of the tail rotor gear box. Fuel was found throughout the fuel system.

According to the pilot, the engine was to receive a major overhaul in about 46 hours.

The engine was examined by the owner/operator without the permission or supervision of the National Transportation Safety Board. According to the owner of the helicopter, metal shavings were found throughout the engine and the number four piston lands and rings were broken. The failure mode of the engine was not determined.

Aircraft

Registration
N8029Z
Reported as
Robinson R-22
Category
Helicopter
Serial number
1049
Airframe hours
1,954
Engine
Lycoming O-320-B2C, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Business · Part 91
Operator
B & A Leasing Corporation
Registered owner
B & A Leasing Corporation
Airworthiness certificate
Standard, Normal
Last inspection
Annual · September 1, 1993 · 20 hours before
Departed
3B3 · Sterling, MA
Destination
PYM · Plymouth, MA

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
50
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land, Multi-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Right
Flight hours
10,500 total · 6,200 in this make and model · 30 in the last 90 days · 20 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
0° at 10 knots
Visibility
10 statute miles
Lowest ceiling
600 ft broken
Temperature
66 °F

FAA reports on this event · 1

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