AD/BR700/10 High Pressure Turbine Time Limits (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.

Rolls Royce Germany Turbine Engines - BR700 Series

AD/BR700/10 High Pressure Turbine Time Limits 8/2007 TX

Applicability:

All BR700-715A1-30, BR700-715B1-30 and BR700-715C1-30 engines, which have Service Bulletin (SB) BR700-72-100801 incorporated.

Note 1:  These engines are known to be installed on, but not limited to Boeing 717 aircraft.

Requirement:

Carry out the following for each individual BR715 HP Turbine Stage 1 Rotor Disc for both Part No. BRH20130 and Part No. BRH20131 and High Pressure (HP) Turbine Stage 2 Rotor Disc for both Part No. BRH19423 and Part No. BRH19427 installed in a BR700-715A1-30, B1-30 or C1-30 engine.

1.    Identify the mandatory decreased maximum approved life for the HP Turbine Stage 1 and Stage 2 Rotor Discs listed in the tables below:

High Pressure (HP) Turbine Stage 1 Rotor Disc	Mandatory Decreased Maximum Approved Life (Flight Cycles)
Part No.	Engine Thrust Rating			Engine Flight Mission
A1-30 Design	B1-30 Design	C1-30 Design	A1-30 Hawaiian	B1-30 Tropical	C1-30 Derated Tropical
BRH2013	15971	13324	10500	17647	3794	7941
BRH20131	15971	13324	10500	17647	3794	7941

High Pressure (HP) Turbine Stage 2 Rotor Disc	Mandatory Decreased Maximum Approved Life (Flight Cycles)
Part No.	Engine Thrust Rating			Engine Flight Mission
A1-30 Design	B1-30 Design	C1-30 Design	A1-30 Hawaiian	B1-30 Tropical	C1-30 Derated Tropical
BRH19423	21165	17800	13372	21165	10893	13461
BRH19427	21165	17800	13372	21165	10893	13461

2.    Record the mandatory maximum approved life in the applicable lifing documentation.

It is mandatory to use the values given in the two tables in requirement 1 of this AD.

Note 2:  The life limits are decreased by the same proportion for all flight missions, thus back to birth pro-rata calculations due to the life limit changes are not required.

Note 3:  EASA Emergency AD 2007-0152-e dated 25 May 2007 refers.

Compliance:

Within 30 days after the effective date of this AD unless previously accomplished.

This Airworthiness Directive becomes effective on 1 June 2007.

Background:

It is necessary to change the life limits of the High Pressure (HP) Turbine Stage 1 and Stage 2 Rotor Discs.  The maximum approved life of these discs is decreased for all flight missions.  This AD has been raised to instruct mandatory decreased maximum approved lives in the BR715 Time Limits Manual (TLM) T-715-3BR for the HP Turbine Stage 1 Rotor Disc for both Part No. BRH20130 and Part No. BRH20131 and of the High Pressure (HP) Turbine Stage 2 rotor Disc for both Part No. BRH19423 and Part No. BRH19427 for all flight missions.  The life limits are decreased by the same proportion for all flight missions, thus back to birth pro-rata calculations due to the life limit changes are not necessary.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

29 May 2007