AWB 55-007

Applicability: This Bulletin refers to Robinson R22 helicopters of all models, and will be of interest to:

• owners of Robinson R22 helicopters;
• maintenance organisations that carry out maintenance on R22 helicopters; and
• Licensed Aircraft Maintenance Engineers who carry out maintenance on R22 helicopters

Purpose: The purpose of this Bulletin is to recommend that registered operators and maintainers of R22s consider the need to continue performing a maintenance operation previously mandated by Australian AD.

Background: AD/R22/27 was issued in 1986 following an accident caused by the vertical fin separating from the tail-boom in flight. A second report of cracking of the fin attachment bracket was also received. AD/R22/27 was not based on Robinson service documents.

In 2009 a review was conducted of all Airworthiness Directives applicable to R22 helicopters. AD/R22/27 was cancelled because it was not based on a foreign Airworthiness Directive or Robinson service document, and because there have been very few defects reported.

Maintenance: The following inspection should be considered on helicopters with vertical fin to horizontal stabilizer attachment brackets that have exceeded 500 hours time in service.

At each scheduled inspection for issue of a new maintenance release, remove the lower vertical fin and:

(a) visually inspect for fretting on the faying surfaces in the vicinity of the fin attachment bolts;
(b) inspect the fin attachment brackets in the horizontal stabilizer for cracking in the vicinity of the fin attachment bolts using a dye penetrant technique.

Recommendation: It is recommended that owners and maintainers of R22 helicopters remain aware of this maintenance task and consider it carefully when planning maintenance of these helicopters.

FMI: www.casa.gov.au/wcmswr/_assets/main/airworth/awb/55/007.pdf