AD/B717/17 Brake Fuses (Cth)

AIRWORTHINESS DIRECTIVE

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 the 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.

Boeing 717 Series Aeroplanes

AD/B717/17 Brake Fuses 8/2005

Applicability:

Boeing Model 717-200 aeroplanes, fuselage numbers 5002 through 5134 inclusive.

Requirement:

1.    Replace the eight brake fuses of the hydraulic quantity limiter by doing either Option 1 or Option 2 in Table 1 of this Directive in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004.

Table 1. - Replacement

Option	Replace eight fuses having part number (P/N) 7918282-5503 with-
		1	New fuses having P/N 7918282-5505.
2	Modified and reidentified fuses having P/N 7918282-5505.

Note 1:  Boeing Alert Service Bulletin 717-32A0031 refers to Parker Hannifin Corporation Stratoflex Products Division Service Bulletin 836SD-8-6-20, Revision 1, dated 23 June 2004, as an additional source of service information for modifying and reidentifying the brake fuses.

2.    Do not install a brake fuse, P/N 7918282-5503, on any aeroplane.

Note 2:  FAA AD 2005-11-03 Amdt 39-14105 refers.

Compliance:

1.    In accordance with Table 2 of this Directive.

Table 2. - Compliance Times

For aeroplanes having-	Compliance time
(1)  Less than 5,000 total flight cycles as of the effective date of this Directive.	Within 3,600 flight cycles after the effective date of this Directive.
(2)  5,000 or more total flight cycles as of the effective date of this Directive.	Within 1,500 flight cycles after the effective date of this Directive.

2.    After the effective date of this Directive.

This Airworthiness Directive becomes effective on 4 August 2005.
Background:	This Directive was prompted by reports indicating that brake fuses of the hydraulic quantity limiter of the main landing gear have failed.  Replacement of the fuses is to prevent loss of both hydraulic and brake systems if one fuse on each hydraulic system were to fail simultaneously, and consequent reduced controllability of the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 June 2005