Brantly B-2 N2113U

Summary

On 28 April 1989 at about 14:30 local time, a Brantly B-2 registered N2113U was involved in an accident near Herkimer, New York, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 April 1989 at 14:30

Classification

Accident

Location

Herkimer, New York, United States

Coordinates

43.0195, -74.9908

Aircraft

Brantly B-2

Registration

N2113U

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

NYC89FA129

1 person died.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.