Federal Aviation Administration January 22, 2007 – Federal Register Recent Federal Regulation Documents

The FAA is adopting a new airworthiness directive (AD) for Rolls-Royce Deutschland Ltd & Co KG (RRD) Dart 528, 529, 532, 535, 542, and 555 series turboprop engines. This AD requires a dimensional inspection of the intermediate pressure turbine (IPT) disk or an ultrasonic inspection of the seal arm contact between the high pressure turbine (HPT) and the IPT disk seal arm and rework or replacement of the IPT disk if wear outside acceptable limits is found. This AD results from reports of a number of HPT disk failures, some of which resulted in portions of the HPT disk being released. We are issuing this AD to prevent HPT disk failure, which can result in an uncontained engine failure and damage to the airplane.

The FAA is superseding an existing airworthiness directive (AD) for Rolls-Royce plc (RR) RB211 Trent 700 series turbofan engines. That AD currently requires initial and repetitive borescope inspections of the high pressure-and-intermediate pressure (HP-IP) turbine internal and external oil vent tubes for coking and carbon buildup, and cleaning or replacing the vent tubes if necessary. This AD requires the same actions but uses more stringent tube replacement criteria than the previous AD. This AD results from a recent incident where an RB211 Trent 700 series turbofan engine had an oil vent tube rupture as a result of blockage, leading to significant loss of engine oil. The incident indicates that further measures are necessary to control carbon buildup in the oil vent tubes. We are issuing this AD to prevent internal oil fires due to coking and carbon buildup, that could cause uncontained engine failure and damage to the airplane.

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 cracking in the wing main landing gear (MLG) rib 5 forward attachment lug, which could affect the structural integrity of the MLG attachment. This AD requires actions that are intended to address the unsafe condition described in the MCAI.