AC 120-42B ETOPS and Polar Ops - Code7700

6/13/08 AC 120-42B(b) Outside the United States, the signatory person holds a U.S. mechanicscertificate with airframe and powerplant ratings, or holds a certificate in accordance with§ 43.17(c) (1) or,(c) Works for an ETOPS maintenance entity and has the requisite experience orspecific training needed to accomplish the task and is authorized to complete the PDSC andreturn the aircraft to service on behalf of the ETOPS maintenance entity; the signatory persondoes not have to hold a U.S. or Canadian certificate.NOTE: An ETOPS maintenance entity is an entity that has been authorized toperform ETOPS maintenance and authorized by the certificate holder tocomplete ETOPS pre-departure service checks. That entity is certificated toengage in part 121 operations; a repair station certificated under part 145, oran entity authorized pursuant to § 43.17(c)(2).(4) The PDSC must be certified complete immediately before each scheduled ETOPSflight. The term “immediately” has historically meant to be no more than 2 to 4 hours before theflight. However, the FAA may grant some relief from this time period under certain conditions.The certificate holder should explain any rational for such deviations in its ETOPS maintenancedocument, which is approved by its CHDO.(5) A PDSC may not be required before all ETOPS flights. The FAA may grant relieffollowing irregular operations because of non-mechanical issues, such as weather or medicalemergency diversions, or when operating ETOPS into specific areas of operation. For example,if an airplane scheduled for an ETOPS flight receives a PDSC before departure and subsequentlymust divert or turn back for reasons other than mechanical, the certificate holder must identify inits ETOPS maintenance document what procedures its flight operations and maintenancepersonnel would follow to preclude performing another PDSC. If a mechanical discrepancydevelops as a result of the diversion or turn back, the certificate holder may have to performanother PDSC. For example, when an overweight landing inspection reveals an ETOPSSignificant System discrepancy that requires maintenance intervention, another PDSC isrequired.(6) In areas where prevailing weather conditions are stable and generally do notapproach extremes in temperature, wind, ceiling, and visibility, such as in the Caribbean/WesternAtlantic (75-minute ETOPS) and Micronesia routes (90-minute ETOPS), the service check maynot be required for the return leg of an ETOPS flight. This check is not precluded by any othermaintenance check.d. Dual Maintenance.(1) ETOPS dual maintenance, otherwise referred to as identical maintenance, multiplemaintenance, and simultaneous maintenance, requires special consideration by the certificateholder. This is to recognize and preclude common cause human failure modes. Properverification processes or operational tests, prior to ETOPS, are required when dual maintenanceon significant systems occurs.Par 301 Page 15