Accident Ayres S-2R Thrush N4216X,
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ASN Wikibase Occurrence # 373096
 
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Date:Tuesday 5 May 1987
Time:19:15 LT
Type:Silhouette image of generic SS2P model; specific model in this crash may look slightly different    
Ayres S-2R Thrush
Owner/operator:Private
Registration: N4216X
MSN: 1973R
Total airframe hrs:6616 hours
Engine model:P&W R-1340-AN-1
Fatalities:Fatalities: 0 / Occupants: 1
Aircraft damage: Substantial
Category:Accident
Location:Williams, CA -   United States of America
Phase: Manoeuvring (airshow, firefighting, ag.ops.)
Nature:Agricultural
Departure airport:
Destination airport:
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
THE PLT REPORTED HE HEARD SOMETHING BREAK. THE SOUND WAS FOLLOWED BY A VIBRATION. THE PLT THEN TURNED TO LAND ON A ROAD. HE WAS UNABLE TO MAINTAIN ALT AND AIRSPEED. THE ROCKWELL S2R LANDED IN A CULTIVATED FIELD AND NOSED OVER AFTER A COLLISION WITH A DIRT BANK. POST ACCIDENT EXAM OF THE PROP HUB ASSEMBLY REVEALED THAT THE COUNTERWEIGHT BEARING SHAFT WAS FRACTURED ON ONE OF THE PROP BLADES. THIS WOULD ALLOW ONE PROP BLADE TO ROTATE AT A DIFFERENT PITCH ANGLE. THE ROCKWELL S2R HAD A TWO BLADED HAMILTON STANDARD 12D40-305 PROP INSTALLED. IT HAD BEEN MODIFIED IN ACCORDANCE WITH STC #SP1408NW WHICH REPLACES THE HAMILTON STANDARD COUNTERWEIGHT BEARINGS WITH MIDWEST AVIATION ROLLERS.

Probable Cause:

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: LAX87DVG06
Status: Investigation completed
Duration: 1 year and 6 months
Download report: Final report

Sources:

NTSB LAX87DVG06

Location

Revision history:

Date/timeContributorUpdates
27-Mar-2024 09:32 ASN Update Bot Added

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