Accident Bell OH-58C N139RD,
ASN logo
ASN Wikibase Occurrence # 191036
 
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Tuesday 1 November 2016
Time:11:30
Type:Silhouette image of generic B06 model; specific model in this crash may look slightly different    
Bell OH-58C
Owner/operator:Helicopter Applicators Inc
Registration: N139RD
MSN: 41257
Year of manufacture:1971
Total airframe hrs:12604 hours
Engine model:Rolls-Royce T63A720
Fatalities:Fatalities: 0 / Occupants: 1
Aircraft damage: Destroyed
Category:Accident
Location:Moore County, NC -   United States of America
Phase: Manoeuvring (airshow, firefighting, ag.ops.)
Nature:Agricultural
Departure airport:Cameron, NC
Destination airport:Cameron, NC
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
The commercial pilot was conducting a local aerial application flight in the restricted-category military surplus helicopter. After loading the helicopter with herbicide, the pilot departed from the staging area; however, during the initial climb, as the helicopter was about 50 ft above the ground, the outboard portion of one of the two main rotor blades separated. The main rotor blades then struck the tailboom, and the helicopter entered an uncontrolled descent to the ground. Metallurgical examination of the fractured main rotor blade revealed a crack with fatigue features emanating from multiple origins in the area of the inertia weight attachment hole.

The helicopter manufacturer, Bell, also a restricted-category type certificate holder for the same model helicopter as the accident helicopter, had published a military alert bulletin (MAB) about 30 years before the accident (revised about 9 years before the accident) and an operations safety notice (OSN) about 9 years before the accident applicable to the main rotor blade that fractured during the accident flight; operators were instructed to conduct initial visual inspections of the blades in the area of the inertia weight screw heads and subsequent inspections at intervals of 8 hours or 32 flights, whichever occurred first. However, the OSN only applied to the airframe serial numbers under the responsibility of Bell. Both the operator and the type certificate holder of the accident helicopter, Rotorcraft Development, indicated that they were not aware of the MAB or the OSN until after the accident. Additionally, a preventive maintenance services inspection program that was published by the previous type certificate holder for the accident helicopter (Garlick Helicopters) did not contain requirements to inspect the main rotor blade per the aforementioned MAB and OSN. Performance of the recurrent inspection required by the MAB and the OSN likely would have detected the fatigue cracks on the main rotor blade before its failure during the accident flight. The Federal Aviation Administration did not require sharing of safety information, such as the MAB and the OSN recurrent inspections, between restricted-category type certificate holders.


Probable Cause: An in-flight failure of a main rotor blade due to fatigue cracks. Contributing to the failure of the main rotor blade was the absence of guidance to the operator to inspect an area of the main rotor blade known to be susceptible to fatigue cracks and the accident helicopter type certificate holder’s lack of information of an existing inspection published by another restricted-category type certificate holder of the same model helicopter.

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: ERA17LA032
Status: Investigation completed
Duration: 3 years
Download report: Final report

Sources:

NTSB
FAA register: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=139RD
http://aerossurance.com/helicopters/oh58c-mrb-fatigue-non-oem-tch/

Location

Media:

Revision history:

Date/timeContributorUpdates
01-Nov-2016 18:33 gerard57 Added
02-Nov-2016 00:44 Geno Updated [Aircraft type, Registration, Cn, Operator, Location, Phase, Nature, Source, Narrative]
02-Nov-2016 17:19 Iceman 29 Updated [Embed code]
21-Nov-2016 18:49 rvargast17 Updated [Cn, Narrative]
10-Nov-2019 14:33 ASN Update Bot Updated [Time, Cn, Country, Departure airport, Destination airport, Source, Damage, Narrative, Accident report, ]
12-Jul-2020 11:33 Aerossurance Updated [Location, Source, Damage, Narrative]
12-Jul-2020 11:52 Aerossurance Updated [Embed code]
03-Aug-2020 07:05 Aerossurance Updated [Embed code]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org