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 39.1 (1) of CAR 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.
Allison Turbine Engines - 250 Series
AD/AL 250/81 Third Stage Turbine Wheels 6/2002
Applicability: Allison 250 - C28 Engines with third stage turbine wheels Part Number (P/N) 6899383 and with Serial Numbers (S/N) listed in Table 1 of this Directive.
Requirement: Remove from service all turbine wheels P/N 6899383 listed by S/N in Table 1 of this Directive.
Note: FAA AD 2002-06-08 refers.
Compliance: Effective 13 June 2002; as per Table 2 of this Directive.
This Airworthiness Directive becomes effective on 13 June 2002.
Background: Fractures of the third stage turbine blade tips and shrouds could cause uncommanded shutdowns. New lower life limits have been established to address this problem.
This Directive requires the removal from service of certain turbine wheels that exceed the new lower life limits.
Table 1. S/N’s of Affected Third Stage Turbine Wheels
HX91428R | HX91489R | HX91707R |
HX91456R | HX91490R | HX91708R |
HX91457R | HX91492R | HX91709R |
HX91428R | HX91489R | HX91707R |
HX91456R | HX91490R | HX91708R |
HX91457R | HX91492R | HX91709R |
HX91458R | HX91493R | HX91710R |
HX91459R | HX91494R | HX91711R |
HX91461R | HX91500R | HX91712R |
HX91462R | HX91501R | HX91713R |
HX91464R | HX91503R | HX91714R |
HX914659 | HX91504R | HX91715R |
HX91465R | HX91506R | HX91721R |
HX91466R | HX91507R | HX91722R |
HX91467R | HX91508R | HX91726R |
HX91468R | HX91510R | HX91733R |
HX91469R | HX91511R | HX91735R |
HX91471R | HX91512R | HX91736R |
HX91472R | HX91513R | HX91738R |
HX91473R | HX91519R | HX91742R |
HX91474R | HX91520R | HX91744R |
HX91475R | HX91522R | HX91748R |
HX91477R | HX91523R | HX91749R |
HX91478R | HX91524R | HX91750R |
HX91480R | HX91525R | HX91754R |
HX91482R | HX91526R | HX91764R |
HX91483R | HX91527R | HX91765R |
HX91485R | HX91528R | HX91766R |
HX91486R | HX91529R | HX91767R |
HX91487R | HX91530R | HX91768R |
HX91488R | HX91706R | HX91769R |
Table 2. Removal Schedule
As of the effective date of this AD | Remove by |
(1) With fewer than 2,800 cycles-since- new (CSN), and fewer than 1,400 hours’ time-since-new (TSN). | 3,000 CSN or 1,500 hours TSN, whichever occurs earlier. |
(2) With between 2,800 and 3,000 CSN (inclusive), and fewer than 1,500 hours TSN. | 200 additional cycles or 100 additional hours, after the effective date of this AD, whichever occurs earlier. |
(3) With fewer than 3,000 CSN, and between 1,500 and 3,000 hours TSN. | 100 additional hours, after the effective date of this AD. |
(4) With between 3,000 and 6,000 CSN (inclusive), and fewer than 1,500 hours TSN. | 200 additional cycles, after the effective date of this AD. |
(5) With between 3,000 and 6,000 CSN and between 1,500 and 3,000 hours TSN. | 200 additional cycles or 100 additional hours, after the effective date of this AD, whichever occurs earlier. |
(6) With more than 6,000 CSN, or more than 3,000 hours TSN | Before further flight. |
James Coyne
Delegate of the Civil Aviation Safety Authority 15 April 2002
The above AD is notified in the Commonwealth of Australia Gazette on 22 May 2002.