Brantly Helicopter B-2 accident near Herkimer, New York, April 28, 1989
On April 28, 1989 at about 2:30 pm local time, a Brantly Helicopter B-2, registered N2113U, was destroyed in an accident near Herkimer, New York. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A FORCED LANDING IN UNSUITABLE TERRAIN DUE TO AN INTERNAL ENGINE FAILURE. THE ENGINE FAILURE SEQUENCE WAS INITIATED BY A FAILED OIL PRESSURE RELIEF SPRING WHICH HAD FAILED IN FATIGUE DUE TO IMPROPER PLATING OF THE SPRING. THE SPRING FAILURE CAUSED OIL STARVATION TO THE ENGINE CRANKSHAFT AND RESULTING FAILURE OF A CONNECTING ROD.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 28, 1989 · about 2:30 pm local time
- Place
- Herkimer, New York · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Brantly Helicopter B-2
- Registration
- N2113U · no longer on the register · serial 161
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRCRAFT WAS FOUND IN A WOODED AREA ABOUT 1-1/2 MILES NORTH OF THE DEPARTURE HELIPORT. ON-SCENE INVESTIGATION REVEALED A HOLE IN THE ENGINE CASE NEAR CYLINDER #4. A LATER ENGINE TEARDOWN SHOWED THAT THE #4 CONNECTING ROD HAD FAILED AT THE CRANKSHAFT JOURNAL. THE JOURNAL DISPLAYED TYPICAL DISCOLORATION AND SCORING FROM OVERHEATING AND A LACK OF LUBRICATION. THE OIL PRESSURE RELIEF VALVE SPRING, P/N 68668, WAS BROKEN INTO 3 PIECES. METALLURGICAL EXAM REVEALED THAT THE SPRING FAILED IN FATIGUE WHICH PROBABLY ORIGINATED FROM PRE-EXISTING CRACKS DEVELOPED AS A RESULT OF HYDROGEN EMBRITTLEMENT. THE GENERAL CONDITION OF THE CADMIUM PLATING ON THE SPRING WAS VERY POOR, AND PLATING IS NOT CALLED OUT IN THE ENGINEERING DRAWING.
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
Pilot
- Certificate: commercial pilot
- Ratings: single-engine sea; rotorcraft: helicopter
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 897 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 1,600 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming VO 360 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
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.