# NTSB BFO94LA100: Robinson R-22, N8029Z, Raynham, MA, June 15, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 15, 1994, 12:45 local (16:45 UTC) - Place: Raynham, MA - Location: 41.9487° N, 71.0731° W: Placed by OpenAirDocs: center of Raynham, MA, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=41.9487&lon=-71.0731&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 5, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 8933 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO94LA100 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8933/pdf - Page: https://openairdocs.org/ntsb/BFO94LA100 ## Probable cause Failure of the number four cylinder piston rings. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - engine assembly,ring - failure,total - Forced landing, descent - 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 (not matched to a registry record) - Reported make and model: ROBINSON R-22 - Category: Helicopter - Serial number: 1049 - Airframe hours: 1954 - Engines: 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. - Pilot; age 50; 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 (OpenAirDocs). - [Accident 19940615047709A](https://openairdocs.org/incident/19940615047709A), Jun 15, 1994: Robsin R22BETA, Raynham, MA, Substantial damage. Low altitude, power loss. Hard landing. Chopped tail. High time engine had metal shavings throught out. Rings broken From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.