AD NUMBER: 2009-07-01
MANUFACTURER: Rolls Royce
SUBJECT: Airworthiness Directive 2009-07-01
SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: It is necessary to change the 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 Emergency Airworthiness Directive (EAD) 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. We are issuing this AD to prevent rotating parts that may have exceeded their low-cycle fatigue life limits from failing, which could result in uncontained engine failure and subsequent damage to the airplane.

FMI: www.faa.gov/regulations_policies/airworthiness_directives/