12-30-88 AC 120-42A airframe-engine combination will be contained in an FAA Airplane Assessment Report. The report will be provided to the Transport Airplane Certification Directorate (FAA Northwest Mountain Region) for approval and to the directors of Flight Standards, and Aircraft Certification Service, for review and concurrence. Following approval of the report, the propulsion and airframe system recommendations will be included in an FAA-approved document that establishes the CMP standard requirements for the candidate airplane. This document will then be referenced in the Operations Specification and the Airplane Flight Manual.
f. ETOPS Type Design Approval. Upon satisfactory completion of the airplane evaluation through an engineering inspection and test program consistent with the type certification procedures of FAR Part 21 and sufficient inservice experience data:
(1) The type design approval will be reflected in the FAA- approved AFM or supplement, and Type Certification Data Sheet or Supplemental Type Certificate which contain directly or by reference the following pertinent information, as applicable:
(i) Special limitations (if necessary), including any limitations associated with a maximum diversion time established in accordance with Paragraph 8c(1).
(ii) Markings or placards (if required);
(iii) Revision to the performance section in accordance with paragraph 10d (6);
(iv) The airborne equipment, installation, and flightcrew procedures required for extended range operations;
(V) Description or reference to a document containing the approved airplane configuration CMP standard;
(vi) A statement to the effect that:
'The type design reliability and performance of this airframe-engine combination has been evaluated in accordance with AC 120-42A and found suitable for (state maximum diversion time) extended range operations with the incorporation oi the approved airplane configuration CMP standard. This finding does not constitute approval to conduct extended range operations.i Type Design Change Process. The FAA directorate responsible for the certification of the type design will include the consideration of extended range operation in its normal monitoring and design change approval functions. Any significant problems which adversely effect extended range operation will be corrected. Modifications or maintenance actions to achieve or maintain the reliability objective of extended range operations Par 8 13
12-30-88 AC 120-42A will be incorporated into the type design CMP standard document.
The FAA will normally coordinate this action with the affected industry. The Airworthiness Directive process will be utilized as necessary to effect a CMP standard change. The current CMP standard will be reflected in Part D of each ETOPS operator's operations specifications.
h. Continued Airworthiness. The type design CMP standard which establishes the suitability of an airplane for extended range operations defines the minimum standards for the operation.
Incorporation of additional modifications or maintenance actions generated by an operator or manufacturer to enhance or maintain the continued airworthiness of the airplane may be made through the normal approval process. The operator or manufacturer (as appropriate) should thoroughly evaluate such changes to ensure that they do not adversely effect reliability or conflict with requirements for extended range approval.
9. INSERVICE EXPERIENCE. In establishing the suitability of a type design in accordance with Paragraph 8 of this AC and as a prerequisite to obtaining any operational approval, in accordance with the criteria of Paragraph 10 of this AC, it should be shown that an acceptable level of propulsion system reliability has been achieved in service by the world fleet for that particular airframe-engine combination. The candidate operator needs also to obtain sufficient maintenance and operation familiarity with the particular airframe-engine combination in question.
Prior to the type design approval, Paragraph 8, it should be shown that the world fleet of the particular airframe-engine combination for which approval is sought can or has achieved, as determined by the FAA (see Appendix 1), an acceptable and reasonably stable level of single propulsion system in-flight shutdown (IFSD) rate and airframe system reliability. Engineering and operational judgment applied in accordance with the guidance outlined in Appendix 1 will then be used to determine that the IFSD rate objective for all independent causes can be achieved. This assessment is an integral part of the determination in Paragraph 8.b. (2) for type design approval. This determination of propulsion system reliability is derived from a world fleet data base containing all in-flight shutdown events and significant engine reliability problems, in accordance with requirements of Appendix 1. This determination will take due account of the approved maximum diversion time, rectification of identified system problems, as well as events where in-flight starting capability may be degraded.
b. Each operator requesting approval to conduct extended range operations should have operational inservice experience appropriate to the operation proposed. Subparagraphs 9.b.(1) (2) (3) contain guidelines for requisite inservice experience. These guidelines may be reduced or increased following review and concurrence on a case-by-case basis by the Director, Flight 14 Par 8
12-30-88 AC 120-42A Standards Service. Any reduction or increase in inservice experience guidelines will be based on an evaluation of the operator's ability and competence to achieve the necessary reliability for the particular airframe-engine combination in extended range operations. For example, a reduction in inservice experience may be considered for an operator who can show extensive inservice experience with a related engine on another airplane which has achieved acceptable reliability. In contrast, an increase in inservice experience may be considered for those cases where heavy maintenance has yet to occur and/or abnormally low number of takeoffs have occurred.
(1) 75-Minute Operation. Consideration may be given to the approval of 75-minute extended range operations for operators with minimal or no inservice experience with the airframe-engine combination. This determination considers such factors as the proposed area of operations, the operator's demonstrated ability to l successfully introduce airplanes into operations, and the quality of the proposed maintenance and operations programs.
(2) 120-Minute Operation. Each operator requesting approval to conduct extended range operations with a maximum diversion time of 120 minutes (in still air) should have 12 consecutive months of operational inservice experience with the specified airframe-engine combination. Inservice experience guidelines may be increased or decreased by the Director, Flight Standards Service, as noted in Paragraph 9b.
(3) 180-Minute Operation. Each operator requesting approval to conduct extended range operations with a maximum diversion time of 180 minutes (in still air) should have previously gained 12 consecutive months of operational inservice experience with the specified airframe-engine combination in conducting 120-minute extended range operations. Inservice experience guidelines may be reduced or increased by the Director, Flight Standards Service, as noted in Paragraph 9b. Likewise, the substitution of inservice experience which is equivalent to the actual conduct of 120-minute ETOPS operations will also be established by the Director, Flight Standards Service, on a caseby-case basis.
OPERATIONAL APPROVAL CONSIDERATIONS. Paragraphs 10.a. through
10.h. detail the criteria for operational approval of extended range operations with a maximum diversion time of 120 minutes to an route alternate (at single-engine inoperative cruise speed in still air). Appendices 4 and 5 serve two functions; first, they provide expanded explanation of the elements contained in this advisory circular and second, they serve to differentiate the criteria for approval of operations less than 120 minutes (75 minutes) and beyond 120 minutes (180 minutes). For approval of 75-minute operations, only certain requirements of this AC apply. (See Appendix 5.)
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AC 120-42A 12-30-88 Requesting Approval. Any operator requesting approval under FAR Section 121.161 for extended range operations with twoengine airplanes (after providing an acceptable evaluation of the considerations in Paragraphs 8 and 9) should submit the requests, with the required supporting data, to the certificate-holding district office at least 60 days prior to the proposed start of extended range operation with the specific airframe-engine combination. In considering an application from an operator to conduct extended range operations, an assessment should be made of the operator's overall safety record, past performance, flightcrew training, and maintenance programs. The data provided with the request should substantiate the operator's ability and competence to safely conduct and support these operations and should include the means used to satisfy the considerations outlined in this paragraph. (Any reliability assessment obtained, either through analysis or service experience, should be used as guidance in support of operational judgments regarding the suitability of the intended operation.)
Assessment of the Operator's Propulsion System Reliability. Following the accumulation of adequate operating experience by the world fleet of the specified airframe-engine combination and the establishment of an IFSD rate objective in accordance with Appendix 1 for use in ensuring the propulsion system reliability necessary for extended range operations, an assessment should be made of the applicant's ability to achieve and maintain this level of propulsion system reliability. This assessment should include trend comparisons of the operator's data with other operators as well as the world fleet average values, and the application of a qualitative judgment that considers all of the relevant factors. The operator's past record of propulsion system reliability with related types of power units should also be reviewed, as well as its record of achieved systems reliability with the airframe-engine combination for which authorization is sought to conduct extended range operations.
Engineering Modifications and Maintenance Program Considerations. Although these considerations are normally part of the operator's continuing airworthiness program, the maintenance and reliability program may need to be supplemented in consideration of the special requirements of extended range operation (Appendix 4). The following items, as part of the operator's program, will be reviewed to ensure that they are adequate for extended range operations:
Engineering Modifications. The operator should provide to the certificate-holding district office all titles and numbers of all modifications, additions, and changes which were made in order to substantiate the incorporation of the CMP standard in the airplanes used in extended range operation.
(2) Maintenance Procedures. Following approval of the changes in the maintenance and training procedures, substantial 16 Par 10
12-30-88 AC 120-42A changes to maintenance and training procedures, practices, or limitations established to qualify for extended range operations should be submitted to the certificate-holding district office 60 days before such changes may be adopted.
(3) Reliability Reporting. The reliability reporting program as supplemented and approved, should be implemented prior to and continued after approval of extended range operation.
from this process should result in a suitable summary of problem events, reliability trends and corrective actions and be provided regularly to the certificate-holding district office. Appendix 4 contains additional information concerning propulsion and airframe system reliability monitoring and reporting.
(4) Approved modifications and inspections which would maintain the reliability objective for the propulsion and airframe systems as a consequence of Airworthiness Directive (AD) actions and revised CMP standards should be promptly implemented. Other recommendations made by the engine and airframe manufacturers should also be considered for prompt implementation. This would apply to both installed and spare parts.
(5) Procedures and centralized control process should be established which would preclude an airplane being dispatched for extended range operation after propulsion system shutdown or primary airframe system failure on a previous flight, or significant adverse trends in system performance, without appropriate corrective action having been taken. Confirmation of such action as being appropriate, in some cases, may require the successful completion of one or more nonrevenue or non-ETOP revenue flights (as appropriate) prior to dispatch on an extended range operation.
(6) The program used to ensure that the airborne equipment will continue to be maintained at the level of performance and reliability necessary for extended range operations.
(7) Engine condition monitoring program.
(8) Engine oil consumption monitoring program.
d. Flight Dispatch Considerations.
(1) General. The flight dispatch considerations specified in this section are in addition to, or amplify, the requirements contained in FAR Part 121 and specifically apply to extended range operations. Although many of the considerations in this AC are currently incorporated into approved programs for other airplanes or route structures, the unique nature of extended range operations with two-engine airplanes necessitates a reexamination of these operations to ensure that the approved programs are adequate for this purpose.
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12-30-88 AC 120-42A
(2) Master Minimum Equipment List (MMEL). System redundancy levels appropriate to extended range operations should be reflected in the MMEL. An operator's MEL may be more restrictive than the MMEL considering the kind of ER operation proposed and equipment and service problems unique to the Systems considered to have a fundamental influence on flight safety may include, but are not limited to the following:
(ї) Electrical, including battery;
(ii) Hydraulic;
(iii) Pneumatic;
(iv) Flight instrumentation;
(V) Fuel;
(vi) Flight control;
(vii) Ice protection;
(viii) Engine start and ignition;
(ix) Propulsion system instruments;
(x) Navigation and communications;
(xi) Auxiliary power-units;
(xii) Air conditioning and pressurization;
(xiii) Cargo fire suppression;
(xiv) Emergency equipment; and
(xv) Any other equipment necessary for extended range operations.
(3) Communication and Navigation Facilities. An airplane should not be dispatched on an extended range operation unless:
(i) Communications facilities are available to provide under normal conditions of propagation at the normal oneengine inoperative cruise altitudes, reliable two-way voice communications between the airplane and the appropriate air traffic control unit over the planned route of flight and the routes to any suitable alternate to be used in the event of diversion;
(ii) Nonvisual ground navigation aids are available and located so as to provide, taking account of the navigation equipment installed in the airplane, the navigation accuracy 18 Par 10
12-30-88 . AC 120-42A necessary for the planned route and altitude of flight, and the routes to any alternate and altitudes to be used in the event of an engine shutdown; and
(iii) Visual and nonvisual aids are available at the specified alternates for the authorized types of approaches and operation minima.
(4) Fuel and Oil Supply.
(i) General. An airplane should not be dispatched on an extended range operation unless it carries sufficient fuel and oil to meet the requirements of FAR Part 121, and any additional fuel that may be determined in accordance with subparagraph
10.d. (4) (ii). In computing fuel requirements, advantage may be taken of driftdown and at least the following should be considered as applicable:
(A) Current forecast winds and meteorological conditions along the expected flightpath at one-engine inoperative.
cruising altitude and throughout the approach and landing;
(B) Any necessary operation of ice protection systems and performance loss due to ice accretion on the unprotected surfaces of the airplane;
(C) Any necessary operation of auxiliary power units;
(D) Loss of airplane pressurization and air conditioning; consideration should be given to flying at an altitude meeting oxygen requirements in the event of loss of pressurization;
(E) An approach followed by a missed approach and a subsequent approach and landing;
(F) Navigational accuracy necessary; and (G) Any known Air Traffic Control (ATC) constraints.
(ii) Critical Fuel Reserves. In establishing the critical. fuel reserves, the applicant is to determine the fuel necessary to fly to the most critical point and execute a diversion to a suitable alternate under the conditions outlined in subparagraph 10.d.(4) (iii)--the Critical Fuel Scenario. These critical fuel reserves should be compared to the normal FAR Part 121 requirements for the flight. If it is determined by this comparison that the fuel to complete the critical fuel scenario exceeds the fuel that would be on board at the most critical point, as determined by Part 121 requirements of the FAR, additional fuel should be included to the extent necessary to safely complete the Par 10 19
AC 120-42A 12-30-88 critical fuel scenario. In consideration of the items listed in subparagraph 10.d. (4) (i), the critical fuel scenario should allow a contingency figure of 5 percent added to the calculated fuel burn from the critical point to allow for errors in wind forecasts, a 5 percent penalty in fuel mileage**, any Configuration Deviation List items, both airframe and engine anti-icing; and account for ice accumulation on unprotected surfaces if icing conditions are likely to be encountered during the diversion. If the APU is a required power source, then its fuel consumption should be accounted for during the appropriate phase(s) of flight.
(**In lieu of an applicant's established value for inservice deterioration in cruise fuel mileage.)
(iii) Critical Fuel Scenario. The following describes a scenario for a diversion at the most critical point. The applicant should confirm the scenario to be used in determining the critical fuel reserve necessary is operationally the most critical considering both time and airplane configuration (e.g., 2 engine versus 1 engine at 10,000 feet, nonstandard airplane configuration not shown to be extremely improbable, paragraph 8.c. (2) (ii) (D)).
At the critical point, consider simultaneous failure of an engine and the pressurization system (critical point based on time to a suitable alternate at the approved one-engine inoperative cruise speed).
(B) Immediate descent to and continued cruise at 10,000 feet at the approved one-engine inoperative cruise speed or continued cruise above 10,000 feet if the airplane is equipped with sufficient supplemental oxygen in accordance with FAR Section
121.329.
(C) Upon approaching destination, descent to 1,500 feet above destination, hold for 15 minutes, initiation of an approach followed by a missed approach and then execution of a
(5) Alternate Airports. An airplane should not be dispatched on an extended range operation unless the required takeoff, destination and alternate airports, including suitable en route alternate airports to be used in the event of engine shutdown or airplane system failure(s) which require a diversion, are listed in the cockpit documentation (e.g., computerized flight listed in the dispatch release for all cases where the planned Suitable en route alternates should also be identified and route of flight contains a point more than one hour flying time at the one-engine inoperative speed from an adequate airport. since these suitable en route alternates serve a different purpose than the destination alternate airport and would normally be used only in the event of an engine failure or the loss of primary airplane systems, an airport should not be listed as a suitable en route alternate unless:
20 Par 10
12-30-88 AC 120-42A
(i) The landing distances required as specified in the AFM for the altitude of the airport, for the runway expected to be used, taking into account wind conditions, runway surface conditions, and airplane handling characteristics, permit the airplane to be stopped within the landing distance available as declared by the airport authorities and computed in accordance with FAR Part 121.197.
(ii) The airport services and facilities are adequate for the applicant operator's approved approach procedure(s) and operating minima for the runway expected to be used; and
(iii) The latest available forecast weather conditions for a period commencing one hour before the established earliest time of landing and ending one hour after the established latest time of landing at that airport, equals or exceeds the authorized veather minima for en route alternate airports in Appendix 3.
addition, for the period commencing one hour before the established earliest time of landing, and ending one hour after the established latest time of landing at that airport, the forecast crosswind component, including gusts, for the landing runway expected to be used should be less than the maximum permitted crosswind for landing.
During the course of the flight, the flightcrew should be informed of any significant changes in conditions at designated en route alternates. Prior to a 120-minute extended range flight proceeding beyond the extended range entry point, the forecast weather for the time periods established in subparagraph 10d(5) (iii), landing distances, and airport services and facilities at designated en route alternates should be evaluated. If any conditions are identified (such as weather forecast below landing minima) which would preclude safe approach and landing, then the pilot should be notified and an acceptable alternate (s) selected.
where safe approach and landing can be made.
Airplane Performance Data. No airplane should be dispatched on an extended range flight unless the operator's Operations Manual contains sufficient data to support the critical fuel reserve and area of operations calculation. The following data should be based on FAA-approved (see Paragraph 8.d. (3)) information provided or referenced in the Airplane Flight Manual.
Detailed one-engine inoperative performance data including fuel flow for standard and nonstandard atmospheric conditions and as a function of airspeed and power setting, where appropriate, covering (A) Driftdown (includes net performance);
(B) Cruise altitude coverage including 10,000 feet;
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AC 120-42A 12-30-88 (C) Holding;
(D) Altitude capability (includes net performance); and (E) Missed approach.
(ii) Detailed all-engine-operating performance data, including nominal fuel flow data, for standard and nonstandard atmospheric conditions and as a function of airspeed and power setting, where appropriate, covering:
(A) Cruise (altitude coverage including 10,000 feet); and (B) Holding.
(iii) Details of any other conditions relevant to extended range operations which can cause significant deterioration of performance, such as ice accumulation on the unprotected surfaces of the airplane, RAM Air Turbine (RAT) deployment, thrust reverser deployment, etc.
(iv) The altitudes, airspeeds, thrust settings, and fuel flow used in establishing the ETOPS area of operations for each airframe-engine combination must be used in showing the corresponding terrain and obstruction clearances in accordance with FAR Section 121.191.
e. Flightcrew Training, Evaluation, and Operating Manuals.
(1) Adequacy of Flightcrew Training and Operating Manuals. The FAA will review inservice experience of critical and essential airplane systems The review will include system eliability levels and individual event circumstances, including crew actions taken in response to equipment failures or unavailabilities. The purpose of the review will be to verify the adequacy of information provided in training programs and operating manuals. The aviation industry should provide information for and participate in these reviews. The FAA will use the information resulting from these reviews to modify or update flightcrew training programs, operating manuals, and checklists, as necessary.
(2) Flightcrew Training and Evaluation Program. The operator's training program in respect to extended range operations should provide training for flight crewmembers followed by subsequent evaluations and proficiency checks in the following areas:
22 Par 10
12-30-88 AC 120-42A (½) Performance.
(A) Flight planning, including all contingencies.
(B) Flight performance progress monitoring.
(ii) Procedures.
(A) Diversion procedures.
(B) Use of appropriate navigation and communication systems.
(C) Abnormal and emergency procedures to be followed in the event of foreseeable failures, including:
(1) Procedures for single and multiple failures in flight that would precipitate go/no-go and diversion decisions.
(2) Operational restrictions associated with these failures including any applicable MEL considerations.
(3) Procedures for air start of the propulsion systems, including the APU, if required.
(4) Crew incapacitation.
Use of emergency equipment including protective breathing and ditching equipment.
(E) Procedures to be followed in the event that there is a change in conditions at designated en route alternates which would preclude safe approach and landing.
(F) Understanding and effective use of approved additional or modified equipment required for extended range operations.
(G) Fuel Management. Flightcrew should be trained on the fuel management procedures to be followed during the en route portion of the flight. These procedures should provide for an independent cross-check of fuel quantity indicators. For example, fuel flows could be used to calculate fuel burned and compared to indicated fuel remaining.
(3) ETOPS Check Airman. The operator should designate specific ETOPS check airman. The objective of the ETOPS check airman program should be to ensure standardized flightcrew practices and procedures and also to emphasize the special nature of ETOPS operations. Only airmen with a demonstrated Par 10 23
AC 120-42A 12-30-88 understanding of the unique requirements of ETOPS should be designated as a check airman.
f. Operational Limitations.
(1) Area of Operation.
(i) An operator may be authorized to conduct extended range operations within an area where the diversion time at any point along the proposed route of flight to an adequate airport is 75, 120 or 180 minutes at the approved one-engine cruise speed (under standard conditions in still air). Appendices 1, 4, and 5 provide criteria for operation at the different diversion times.
(ii) The area which meets the considerations in Paragraph 9.1.(1) (i) may be approved for extended range operations with two-engine airplanes and should be specified in the operations specifications as the authorized area of operations.
(2) Flight Dispatch Limitation. The flight dispatch limitation should specify the maximum diversion time from a suitable airport an operator can conduct a particular extended range operation. The maximum diversion time at the approved oneengine inoperative cruise speed (under standard conditions in still air) should not be any greater than the value established by subparagraph 10.f. (1) (i).
Use of Maximum Diversion Time. The flight dispatch considerations should ensure that extended range operation is limited to flight plan routes where the approved maximum diversion time to suitable airports can be met. Operators should provide for:
Compliance with FAR Section 121.565 where, upon occurrence of an in-flight shutdown of an engine, the pilot should promptly initiate diversion to fly to and land at the nearest airport, in point of time, determined to be suitable by the flightcrew.
(B) A practice to be established such that in the event of a single or multiple primary system failure, the pilot will initiate the diversion procedure to fly and land at the nearest suitable airport, unless it has been demonstrated that no substantial degradation of safety results from continuation of the planned flight.
(ii) Criteria for Maximum Diversion Times. The criteria for different maximum diversion times are detailed in Appendices 1, 4, and 5.
(3) Contingency procedures should not be interpreted in 24 Par 10