AD FAA-2021-0257

The FAA proposes to adopt a new airworthiness directive (AD) for certain Rolls-Royce Deutschland Ltd & Co KG (type certificate previously held by Rolls-Royce Deutschland GmbH, formerly BMW Rolls- Royce GmbH) (RRD) BR700-710A2-20 model turbofan engines. This proposed AD was prompted by flight data obtained from airplanes equipped with certain Rockwell Collins avionics and auto-throttle systems that demonstrated significant oscillation of the engine rotor revolution speed during flight. This proposed AD would require initial and repetitive recalculation of the consumed and remaining service life of certain life-limited parts (LLPs). This proposed AD would also require removal of an LLP prior to its approved life limit or within 90 days after the effective date of this AD, whichever occurs later. The FAA is proposing this AD to address the unsafe condition on these products.