AD/Bell 214/8 Hub Locking Plates (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 214/8 Hub Locking Plates 14/2018

Applicability:

Bell Helicopter Textron Inc. (BHTI) model 214B and 214B-1 helicopters, serial numbers (S/N's) 28001 to 28070, certificated in any category, equipped with upper and lower locking plates, part numbers (P/N's) 214‑010-231-101 and 214‑010‑232‑101.

Requirement:

1.    Replace P/N 214-010-232-101 lower locking plate and P/N214-010-231-101 upper locking plate, with locking plate P/N 214-010-569-101 in accordance with Part I of BHTI Alert Service Bulletin (ASB) 214-86-36 dated 8 October 1986, as in force from time to time.

2.    Visually inspect the hub and lower hub nut assembly for slippage in accordance with Part II of BHTI ASB 214-86-36 dated 8 October 1986, as in force from time to time.

3.    Perform the following in accordance with Part III of BHTI ASB 214-86-36, dated 8 October 1986, as in force from time to time:

a.    Inspect the hub locking plate P/N 214-010-569-101 for cracks;

b.    If a crack is found during this inspection, before further flight, replace the hub locking plate with a serviceable part;

c.    Retorque the lower hub nut and install locking plate P/N 214-010-569-101, as detailed in Requirement paragraph 1.

Note 1:  Installation instructions for the scissors and sleeve may be found in the BHTI 214B Maintenance Manual, Chapter 65-20-00.

Note 2:  FAA AD 87-11-06 refers.

Compliance:

1.    Unless previously accomplished, within the next 50 hours’ time in service or within 30 days after the commencement date of this AD, whichever occurs first.

2.    Within the next 25 hours' time in service after completing the requirements of paragraph 1, and thereafter at intervals not to exceed 25 hours' time in service since the most recent inspection.

3.    Within the next 500 hours' time in service after completing the requirements of paragraph 1 and thereafter at intervals not to exceed 500 hours' time in service since the most recent inspection.

This AD commences on 10 July 2018.

Background:

In May 1986, a Bell model 214ST helicopter experienced loss of collective control forcing a rapid, but successful ditching at sea. Subsequent investigation revealed that loss of collective control resulted from failure of the collective hub bearing retention nut lower locking plate which allowed the collective hub nut to unscrew. The actions specified in this Directive are intended to prevent failure of the collective hub locking plate and subsequent loss of control of the helicopter.

Pieter van Dijk
Delegate of the Civil Aviation Safety Authority

4 July 2018