AC 120-42B ETOPS and Polar Ops - Code7700

6/13/08 AC 120-42Bdecisions successfully throughout the flight. The suitability of an en route alternate airport for anairplane that encounters an in-flight situation that necessitates a diversion during ETOPSoperations is based on a determination that the airport still is suitable for the circumstances, andthe weather and field conditions at that airport permit an instrument approach to be initiated anda landing completed.207. ETOPS IN-SERVICE EXPERIENCE REQUIREMENTS.a. When AC 120-42 was first released in 1985, two-engine ETOPS was a new concept andETOPS approvals were sought on airframe-engine combinations that were already in service.Hence, it was logical to establish criteria for approvals based on in-service experience. At thatsame time, the FAA recognized the possibility that other approval methods could be developedwithout in-service experience, and accordingly, provided statements that recognized thoseoptions. The original two-engine ETOPS requirements for engine reliability were based on aworld fleet in-service experience of 250,000 hours. For 120-minute ETOPS, the FAAadditionally required the certificate holder to have 12-consecutive months of operationalin-service experience with the airplane-engine combination (AEC). For 180-minute ETOPS, theFAA required the certificate holder to have previously gained 12 consecutive months ofoperational in-service experience with the specified AEC conducting 120-minute ETOPS. Thesebasic, two-engine in-service requirements have been retained and are discussed in Appendix 3.Achieving these levels of experience, combined with the required levels of engine reliability, isan acceptable means of attaining ETOPS approval for operators of two-engine airplanes.b. At the time AC 120-42A was drafted, the FAA recognized that a reduction oftwo-engine in-service experience requirements or substitution of in-service experience onanother airplane would be possible. Any reduction was to be based on an evaluation of thecertificate holder’s ability and competence to achieve the necessary reliability for the particularAEC in ETOPS. For example, a reduction in in-service experience would be considered for acertificate holder who could show extensive in-service experience with a related engine onanother airplane that had achieved acceptable reliability. The FAA also allowed certificateholders unable to initially fly ETOPS routes at the lesser thresholds to make use of ETOPSsimulation or demonstration programs in their application for 180-minute ETOPS. Eventuallyspecific guidance material (AC 120-42A, appendix 7, Accelerated ETOPS OperationalApproval) was developed by the FAA permitting ETOPS without accumulating in-serviceexperience in the airplane-engine combination. Most subsequent ETOPS approvals have beengranted under these guidelines and this method is retained in Appendix 3.208. OPERATIONAL RELIABILITY AND SYSTEMS SUITABILITYREQUIREMENTS.a. The safety of long-range operations such as ETOPS depends on the reliability of allairplane systems including the propulsion systems. Time-limited systems such as cargocompartment fire suppression/containment capability must be considered (§ 121.633). Thecertificate holder must also have an established program that monitors the reliability of systemssignificant to ETOPS (§ 121.374).Par 206 Page 11