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ETOPS (Extended Twin Engine Operations)
#1 Posted : Monday, December 23, 2013 12:32:44 AM(UTC)
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Joined: 9/7/2013(UTC)
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ETOPS (Extended Twin Engine Operations) : Compiled By : Capt. Arun Kumar (G.I, HICA, Karnal)

The FAA in 1953, having recognised piston engine limitations, introduced the '60-minute rule' for 2 engine aircraft. This rule states that the flight path of these types of aircraft shall not be further than 60 minutes' flying time from an adequate airport. This forced these aircraft, on certain routes, to fly a dogleg path to stay within regulations; they were totally excluded from certain routes due to lack of en-route airports. The 60-minute period is also called 60-minute diversion period. The totally excluded area is called the Exclusion Zone.
 This Civil Aviation Requirements provides requirements for obtaining DGCA approval for twin engine aeroplanes to operate over a route that contains a point farther than one hour flying time at the normal one-engine inoperative cruise speed (in still air) from an adequate airport.
 Extended Twin Engine Operations (ETOPS) requirements are applicable to routes over water as well as remote areas over land.
 The purpose of ETOPS is to provide very high level of safety while facilitating the use of twin engines on routes, which were previously restricted to three or four engine aircraft. ETOPS operation also permits more effective use of an airline resource.


 The requirements stipulated in this CAR are applicable to turbo propeller, turbojet and turbofan aeroplanes transiting oceanic areas or routes entirely over land.
 Operators cannot operate a twin engine aircraft of AUW more than 5700 kg beyond 60 minutes on single engine inoperative cruise speed unless approved by DGCA for ETOPS.
 The segment of operation beyond 60 minutes will be termed as Extended Twin Engine Operation (ETOPS) and this will require prior approval of DGCA.
 This is identical to Extended Range operations (EROPS)

To be eligible for extended range operations the specified airframe/engine combination should have been certificated to the Airworthiness Standards of Transport Category aeroplanes by FAA of USA or JAA or by any other regulatory authority acceptable to DGCA

 ETOPS Segment:

ETOPS segment starts at the ETOPS entry point and finishes when the flight path is back and remains within 60-minute area from an adequate airport.

The Extended Range Operations are covered under categories viz. 75 minutes, 120 minutes and 180-minutes diversion time (the approval to operate may be extended in steps of 15 minutes), as explained below:

a) 75 minute operation:

Approval to carry out extended range operation with 75 minutes diversion time may be granted by DGCA to an operator with minimal or no in-service experience with particular airframe engine combination. This approval will be based on such factors as the proposed areas of operation, the operators demonstrated ability to successfully introduce aircraft into operation, and the quality of the proposed maintenance and operation program. Special case by case operational approval may be granted beyond 75 minutes diversion time (in steps of 15 minutes) with limited evaluation of service experience at the time of the application. For this approval, the service experience of Airframe –engine combination may be less than 2,50,000 hours in the world fleet.

b) Up to 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 minimum of 12 consecutive months of operational in service experience with the specified airframe engine combination. Normally the accumulation of at least 2,50,000 engine hours in the world fleet (not necessarily on a particular airframe) will be necessary before the proposal is considered. Where the engine experience on another type of aeroplane is applicable to the candidate aeroplane, the candidate aeroplane should normally obtain a significant portion of the 2,50,000-engine hrs experience. This number of engine hours maybe reduced if sufficient data is available to prove reliability of the engine. In the event that a particular engine is derived from an existing engine the required operational experience is subject to establishing the degree of hardware commonalties and operating similarities.

c) Above 120 minute and upto 180 minutes operation:

Each operator requesting approval for maximum diversion time of 180 minutes (in still air) should have held current approval for 120 minutes ETOPS for a minimum period of 12 months with a corresponding high level of demonstrated propulsion system reliability.


1. Adequate airport:
Adequate airport is an airport meeting the safety requirements for takeoff and landing for commercial and non-commercial operations. It should be anticipated that at the expected time of use:
(a) The aerodrome will be compatible with the performance requirements for the expected landing weight and will be available and equipped with necessary ancillary services such as ATC, sufficient lighting, communications, weather reporting, navigation aids, refueling and emergency services and

(b) at least one let down aid (ground radar would so qualify) will be available for an Instrument approach.

2. Suitable airport
Suitable airport is an adequate airport with weather reports or forecast or any combination thereof indicating that the weather conditions are at or above operating minima as specified in the operations specification and the field condition report indicates that a safe landing can be accomplished at the time of the intended operations.

3. Diversion/ Enroute alternate airport:
Diversion/ Enroute alternate airport means an airport at which an aircraft may land if a landing at the intended airport is inadvisable. The aerodrome will be available and equipped with necessary ancillary services such as ATC, sufficient lighting, communications, weather reporting, navigation aids, emergency services etc.

4. Auxiliary Power Unit (APU):
A gas turbine engine intended for use as a power source for driving generators, hydraulic pumps and other aeroplane accessories, equipment and/or to provide compressed air for aeroplane pneumatic system.

5. Extended Range Operation:
Extended Range Operations are those flights conducted over a route that contains a point farther than one hour flying time at the approved one engine inoperative cruise speed ( under standard conditions in still air ) from an adequate airport.

6. Extended Range entry Point:
The extended range entry point is the point on the aeroplanes out bound route which is one-hour flying time at the approved single engine inoperative cruise speed (under standard conditions in still air) from an adequate airport.

7. In - Flight Shutdown (IFSD):
When an engine ceases to function in flight and is shutdown, whether self-induced, crew initiated or caused by some other external influence (i.e. IFSD for all cases; for example due to flameout, internal failure, crew initiated shutoff, foreign object ingestion, icing, inability to obtain and/or control desired thrust etc.).
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