AD/Bell 214/9 Main Rotor Yoke Assembly (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct an unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron 214B and 214B-1 Series Helicopters

AD/BELL 214/9 Main Rotor Yoke Assembly 14/2018

Applicability:

Bell Helicopter Textron Inc. (BHTI) model 214B and 214B-1 helicopters, serial numbers (S/N's) 28001 through 28070, equipped with main rotor yoke assembly (assembly) part number (P/N) 214-010-105-001, certificated in any category.

Requirement:

1.    Replace main rotor yoke assembly (assembly), part number (P/N)
214-010-105-001.

2.    Install new airspeed versus altitude decals, P/N 214-075-256-105 for BHTI Model 214B-1 and P/N 214-075-256-107 for Model 214B helicopters.

3.    Inspect the yoke for straightness in accordance with the applicable maintenance manual for the helicopter, as in force from time to time.

Note 1:  BHTI Alert Service Bulletin No. 214-87-37 Revision A, dated 10 September 1987, as in force at the commencement of this AD, pertains to this AD.

Note 2:  FAA AD 93-21-10 refers.

Compliance:

1.    a.     For assemblies that have 3,700 hours' or less time-in-service on the commencement date of this airworthiness directive (AD), replace the assembly on or before reaching 3,750 hours' time in service.

b.    For assemblies that have more than 3,700 hours' time-in-service on the commencement date of this AD, replace the assembly within the next 50 hours' time-in-service.

2.    Unless already accomplished, within 50 hours' time-in-service after the commencement date of this AD.

3.    Within 50 hours’ time in service, unless previously accomplished, and thereafter at intervals not to exceed 1,200 hours' time-in-service.

This AD commences on 17 July 2018.

Background:

This AD is prompted by an analysis that revealed a deterioration of residual compressive stresses in the main rotor yoke assembly with increased time in service.

The actions specified by this AD are intended to prevent failure of the assembly, loss of the main rotor, and subsequent loss of control of the helicopter.

Pieter van Dijk
Delegate of the Civil Aviation Safety Authority

9 July 2018