AC 120-42B ETOPS and Polar Ops - Code7700

AC 120-42B 6/13/08For example, in emergencies such as loss of cabin pressure, current regulations require adequateoxygen supplies but do not require the operator to consider the amount of extra fuel necessary toreach a diversion airport.(1) An analysis of operational data shows that between 1980 and 2000, 33 of the 73cruise depressurization events on one manufacturer’s airplanes occurred on airplanes with morethan two engines.(2) A study conducted by this manufacturer using a modern four-engine aircraftcarrying normal route planning fuel reserves raises issues about the adequacy of the current fuelplanning requirements in the event of a diversion.d. Operational data shows that the diversion rate for all airplane-related and non-airplanerelatedcauses are comparable between two-engine airplanes and airplanes with more than twoengines. Consequently, the FAA has found that there is a need for all passenger carryingoperations beyond 180 minutes from an adequate airport to adopt many of the ETOPSrequirements that have been based on sound safety principles and successfully proven over manyyears of operations. Accordingly, the FAA revised § 121.161 to include passenger-carryingairplanes with more than two engines in these long-range operations.203. EXTENDED OPERATIONS.a. Since 1985, the acronym, ETOPS, has been defined as “extended twin-engineoperations” and has been limited to part 121 airplanes with only two engines. Current regulationshave extended these applications to all passenger-carrying airplanes operating in both 14 CFRparts 121 and 135, and the acronym has now been redefined to mean “extended operations.”This is to acknowledge the similarity of certain long-range passenger-carrying operations of allairplanes operating today, and the common issues that impact such operations.b. Since 1988, the ETOPS limit for two-engine airplanes has been 180 minutes from anadequate airport at an approved one-engine inoperative cruise speed under standard conditions instill air (excluding the limited authority in the North Pacific given under EPL 20-1, 207-MinuteETOPS Operational Approval Criteria, dated March 21, 2000). Service experience has shownthat although limited, this authority has satisfactorily supported the vast majority of the world’scurrent aviation routes.c. Those areas not supported within 180-minute diversion authority tend to be routes overremote areas of the world that are uniquely challenging to the operation. These areas include theSouth Polar Region, a small section in the South Pacific, the southern South Atlantic Oceanbetween South America and Africa, the southern Indian Ocean and the North Polar area undercertain winter weather conditions. The additional operational challenges of these routes areequally demanding of all airplanes, regardless of the number of engines, and include such issuesas extremes in terrain and meteorology, as well as limited navigation and communicationsinfrastructure. Support of a necessary diversion and subsequent recovery in such areas demandsadded training, expertise, and dedication from all certificate holders. The development of ETOPSrequirements is intended to address all these issues.Page 6 Par 202