Bell 47-D1 N4702S

Summary

On 15 November 1995 at about 16:00 local time, a Bell 47-D1 registered N4702S was involved in an accident near Jasper, Florida, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

15 November 1995 at 16:00

Classification

Accident

Location

Jasper, Florida, United States

Coordinates

30.5094, -82.9490

Aircraft

Bell 47-D1

Registration

N4702S

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

MIA96LA028

Nobody was injured.

IMPROPER MAINTENANCE AND INSPECTION OF THE CARBURETOR SYSTEM BY MAINTENANCE PERSONNEL DURING THE LAST ANNUAL INSPECTION WHICH RESULTED IN A PARTIAL LOSS OF ENGINE POWER DUE TO CARBURETOR ICE. CONTRIBUTING TO THE ACCIDENT WERE: THE PILOT'S FAILURE TO PERFORM AN ADEQUATE PREFLIGHT AND ENGINE RUN-UP, AND THE CARBUETOR ICING CONDITIONS.

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

Read the full NTSB narrative

THE PILOT STATED HE WAS MAKING AN APPROACH FOR LANDING AT A FIELD SITE WHEN THE HELICOPTER EXPERIENCED A PARTIAL LOSS OF ENGINE POWER. HE LOWERED THE COLLECTIVE AND ROLLED THE THROTTLE TO THE FULL ON POSITION. THE HELICOPTER COLLIDED WITH POWER LINES AND THE GROUND. REVIEW OF THE AIRCRAFT LOG BOOKS REVEALED THAT THE LAST ANNUAL INSPECTION WAS COMPLETED 3 MONTHS BEFORE THE ACCIDENT. THE CARBURETOR WAS NOT APPROVED FOR USE BY THE FRANKLIN ENGINE COMPANY. EXAMINATION OF THE CARBURETOR HEAT CONTROL VALVE REVEALED AN INCORRECT SPRING INSTALLED, AND THE CARBURETOR HEAT COULD NOT BE ACTIVATED FROM THE COCKPIT. THE CARBURETOR ICING PROBABILITY CHART SHOWS THE POSSIBILITY OF CARBURETOR ICING CONDITIONS BASED ON THE WEATHER AT THE TIME OF THE ACCIDENT. PRIOR TO THE APPROACH, THE PILOT HAD COMPLETED THE BEFORE-LANDING CHECK WITHOUT THE AID OF A CHECKLIST, AND THE CARBURETOR HEAT WAS NOT TURNED ON.

Quoted verbatim from the NTSB record.