Hughes 269C N8642F

Summary

On 22 March 1989 at about 22:01 local time, a Hughes 269C registered N8642F was involved in an accident near De Kalb, Illinois, United States. 2 people were on board and one was seriously injured, one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

22 March 1989 at 22:01

Classification

Accident

Location

De Kalb, Illinois, United States

Coordinates

41.8900, -88.7501

Aircraft

Hughes 269C

Registration

N8642F

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Business

Phase of flight

Not recorded

Route

Aurora → Rockford

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

CHI89FA062

1 person was seriously injured.

FATIGUE FAILURE OF THE NUMBER FOUR CONNECTING ROD WHICH RESULTED IN AN ENGINE FAILURE. FACTORS IN THE ACCIDENT WERE THE BROKEN RING IN THE NUMBER ONE PISTON AND A DETERIORATED CENTER MAIN BEARING.

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

Read the full NTSB narrative

WHILE RETURNING FROM A POWER LINE PATROL THE ENGINE LOST POWER AND AN AUTOROTATION WAS MADE INTO TREES. THE #4 CONNECTING ROD FRACTURED THROUGH THE BEARING STRAP ON ONE SIDE AND PUNCTURED A HOLE IN THE CRANKCASE. SAFETY BOARD METALLURGICAL EXAMINATION REVEALED FATIGUE BEACH MARKINGS ON THE MAJORITY OF THE FRACTURE SURFACE. ADDITIONAL EXAMINATION SHOWED DETERIORATION OF THE CENTER MAIN BEARINGS AND THE FAILURE OF THE TOP RING ON THE #1 PISTON. THE RING FAILURE HAD WORN A GROOVE IN THE PISTON ALMOST THROUGH TO THE 2ND RING GROOVE. SPARK PLUGS WERE NORMAL EXCEPT FOR OIL DEPOSITS ON THE #1 CYLINDER PLUGS. PILOT STATED THAT HE HAD ADDED 3 QTS OF OIL DURING REFUELING DAY OF ACCIDENT.

Quoted verbatim from the NTSB record.