The FAA last month issued a final rule on ETOPS (extended-range twin-engine operational performance standards) that allows operators of commercial aircraft–now including Part 135–to fly virtually anywhere (up to 240 minutes single-engine flying time from a suitable diversion airport), provided the aircraft is capable of protecting passengers and flight crew during an emergency diversion of any length.
The rule formalizes existing policy, industry best practices and international standards to ensure long-range flights operate safely across hostile environments such as over the North and South Poles, the South Atlantic between South America and Africa and the southeastern South Pacific Ocean.
Like all previous ETOPS approvals, this new rule is area specific and includes operator experience and minimum equipment requirements.
Since aircraft occasionally divert for non-engine mechanical problems or passenger medical emergencies, the rule requires that airplane systems be able to support lengthy diversions in remote and sometimes harsh environments.
The rule effectively changes the current limitations and opens routes for twin-engine passenger and cargo airplanes and sets uniformly high standards for all commercial passenger airplanes when they fly routes that are more than three hours’ flying time from an airport.
But there are some notable differences between Part 121 and Part 135 ETOPS approvals. Under the new rule, Part 121 operators can receive ETOPS approval to conduct ETOPS with diversion times beyond 240 minutes between specified city pairs on routes in the Pacific oceanic areas between the U.S. West Coast and Australia, New Zealand and Polynesia; the South Atlantic oceanic areas; the Indian oceanic areas; the oceanic areas between Australia and South America; and the South Polar Area.
For Part 135 operations, ETOPS flights are limited to no more than 240 minutes (with one engine inoperative) from an adequate airport. According to the FAA, the Part 135 industry agreed that a 240-minute diversion was sufficient to meet its needs because Part 135 on-demand flight operations have few restrictions on the type of airport required for use.
Consequently, the number of airports that could be used as an ETOPS alternate is far greater than the number available for a Part 121 ETOPS operator. Alternate airports usable by Part 135 operators are not required to have airline-equivalent safety standards or a minimum rescue and firefighting service. Because of the range limitations in some small jets, the 240-minute limit will not restrict flight operations.
The new rule takes into account the extraordinary reliability of today’s aircraft engines. It covers the design, maintenance and operation of airplanes and engines for ETOPS flights, including special maintenance requirements (except for aircraft with three or more engines), equipment mandates and specific ETOPS crew training.
The rule also requires proactive flight planning, crew training and plans to have facilities at or near each diversion airport that will protect passengers and crew from the elements and make them comfortable.
“Twenty-one years of ETOPS experience shows us that modern jet engines rarely shut down in flight,” said FAA Administrator Marion Blakey. “Our new safety requirements for long-range flight are designed to prevent mechanical problems and protect passengers and flight crew in the rare event of an emergency diversion.”
In formulating the new regulations, the FAA sought advice from a broad range of domestic and international aviation experts. In 2000, the agency chartered an aviation rulemaking advisory committee (ARAC) to review existing policy and requirements and develop standardized requirements for extended operations in the 21st century. The new rule is based largely on the committee’s report, which reflects a consensus about necessary changes.
The implementation of extended operations has involved an evolutionary process of ever-increasing approvals based on industry needs. Two-engine extended operations increased worldwide from fewer than 1,000 per month in 1985 to more than 1,000 per day in 2004. Meanwhile, extended- operations engine reliability has improved to the point that engine shutdowns occur less than half as often as they did in the 1980s.
“In light of the dramatic increases in long-distance flights, this rule will open up new routes for more aircraft and will raise the bar on safety,” Blakey said. An FAA spokesman said, “If someone came to us and wanted to go on a new route we would look at it on a case-by-case basis. We would approve anything, such as Rio to Perth.”
The FAA noted in its final rule that ETOPS provides benefits related to savings in time, fuel and operational efficiencies. But the safety of these operations depends on the risk of critical loss of engine thrust, additional system failures during a diversion for any cause, the distance from an adequate airport used in a diversion and the conditions encountered upon arrival at the diversion airport. In the Rio to Perth example, the great circle route would go over part of Antarctica.
Part 121 domestic, U.S. flag and supplemental rules have limited the amount of time (at engine-out flying speed) two-engine airplanes could be from an airport. In the past, the risks associated with longer flights were accepted as a function of the number of engines on an airplane and were based on the reliability of engines existing at the time the Part 121 rules were initially issued. Airplanes with more than two engines had minimal Part 121 regulatory guidance since engine and system redundancies reduce the safety risk associated with engine failures during diversions.
Current Part 121 regulations for airplanes with more than two engines require adequate oxygen supplies to address emergencies but do not explicitly require the operator to consider other risk-mitigation measures, such as providing the extra fuel necessary to reach a diversion airport.
Likewise, the FAA has regulated turbine-powered on-demand operations under separate Part 135 guidance, which specifies performance criteria when an engine is inoperative but not any restrictions on the potential distance and amount of time from an airport. A lack of regulatory oversight in areas of equipment requirements and fuel planning for a maximum diversion creates a safety risk apart from engine reliability.
As engine reliability increased during the previous three decades, the airline industry has put increasing pressure on the FAA to recognize technological advances and allow Part 121 two-engine airplanes to fly farther from airports than Part 121 allowed. The FAA developed advisory circulars that provided guidance for the operation of Part 121 two-engine airplanes beyond the regulatory limits.
These ACs introduced the term “ETOPS” for these extended operations and addressed airplane and engine design aspects, maintenance programs and operations. Under this guidance, ETOPS operations for Part 121 two-engine airplanes are permitted to fly up to 180 minutes from an airport sufficient to accommodate a landing provided certain criteria are met.
The FAA thus authorizes qualified operators to engage in long-range operations in remote areas. As a result of the FAA’s ETOPS programs, operators of two-engine airplanes can fly over most of the world other than the south polar region, a small section in the South Pacific, and the north polar area under certain winter weather conditions.
With the growing success of the current ETOPS guidelines established for Part 121 two-engine operators, the FAA decided in the 1990s that it could no longer continue to administer the ETOPS program as a special authorization under an operating rule. It also recognized that there were certain aspects of the ETOPS guidelines applicable not solely to two-engine airplanes.
Also during this period, the International Civil Aviation Organization established international standards requiring member states to define diversion time thresholds for all two-engine airplane operations. For the U.S., this requirement includes airplanes operated under Part 135. In addition, the airline industry requested that the FAA develop standards extending the existing limit beyond which two-engine airplanes can operate.
In June 2000 the FAA tasked the ARAC with codifying the existing policies and practices to be applicable to all airplanes, regardless of the number of engines, by developing comprehensive ETOPS standards for Part 25, 33, 121 and 135 as appropriate. The FAA also tasked the ARAC with developing ETOPS operational requirements for diversion times greater than 180 minutes to whatever extent is justified.
Also during this period, the agency developed guidance for polar operations. These operations became more commonplace with the opening of Siberian airspace after the fall of the former Soviet Union. Although not defined as ETOPS, this guidance has been expanded in the new final rule to include both the north and south polar areas and has been incorporated into the overall ETOPS rule package. This aspect of the rule applies to all turbine-powered multi-engine operations, including all-cargo operations.
The FAA is adopting a compliance schedule to allow an orderly transition to future safety requirements as the industry adjusts to the broader ETOPS operating criteria. “We recognize that, in some cases, it is appropriate to permit existing airplanes to continue to operate under existing authorization,” the agency said. “It is also appropriate in some cases to delay implementation of certain portions of the rule to minimize its economic impact.”
The FAA set a one-year compliance date for most requirements involving a set-up or installation program. In addition, it provided grandfather provisions for Part 121 ETOPS operations using airplanes with more than two engines and, for eight years, for all ETOPS operations conducted under Part 135.