ETOPS ? EDTO?
Reference : CAD 513 – EXTENDED DIVERSION TIME OPERATIONS (EDTO)
重點:
ETOPS, EDTO 吾係講緊隻機既performance 咁簡單!
講緊係Operations! Cert (approval) for operator and aircraft type!
ETOPS 計60mins distance 同EDTO 計60mins distance 方法不同!
(EDTO for twin engine threshold time is 60 mins; for three or more engine is 120 or 180 mins)
What’s ETOPS? EDTO? (According to CAD 513)
Extended Range Twin Operations (ETOPS) enable properly certificated twin-engined aeroplanes operated by appropriately qualified flight crew to fly further than a threshold time of 60 minutes at One Engine Inoperative (OEI) cruise speed. In accordance with International Civil Aviation Organization (ICAO) Annex 6 Part I, such requirement is renamed as Extended Diversion Time Operations (EDTO) and is expanded to include the operation of aeroplanes with three and four engines. Any operation that is planned to involve flight by a multi-engined public transport aeroplane (with two or more turbine engines) where the diversion time to an en-route alternate aerodrome is greater than the threshold time will be considered as Extended Diversion Time Operations (EDTO).
小總結:
ETOPS and EDTO 都係apply 在muti-engine aircraft’s operations. ETOPS 既T就係指twin engine; 如果3個或者4個engine 就用EDTO 呢個Terms. 值得留意既係EDTO 先係ICAO standard 既野; 基本上家下我地吾再講ETOPS, 而係用EDTO去代替, 畢竟CAD513 都係叫EDTO
By definition: EDTO 就係the approval for operator and specific aircraft type t0 fly the turbine engine aeroplane to an en-route alternate aerodrome, with the diversion time greater than threshold time!
Further more reading –
Alternate Aerodrome 有3種! – T/O ALTN, En-route ALTN, DSTN ALTN~
Alternate aerodrome
An aerodrome to which an aircraft may proceed when it becomes either impossible or inadvisable to proceed to or to land at the aerodrome of intended landing where the necessary services and facilities are available, where aircraft performance requirements can be met and which is expected to be operational if required. Alternate aerodromes include the following:-
- Take-off alternate
- En-route alternate
- Destination alternate
CAD 513 有講3種Alternate 既分別, 但重點係Alternate aerodrome 要有2個baic條件:
- ALTN 有 necessary services (服務)
- ALTN 有 necessary facilities (設施)
Threshold time
The range, expressed in time, established by CAD to an en-route alternate aerodrome, whereby any time beyond requires an EDTO Approval from CAD.
Extended Range Twin Operations (ETOPS) enable properly certificated twin-engined aeroplanes operated by appropriately qualified flight crew to fly further than a threshold time of 60 minutes at One Engine Inoperative (OEI) cruise speed. In accordance with International Civil Aviation Organization (ICAO) Annex 6 Part I, such requirement is renamed as Extended Diversion Time Operations (EDTO) and is expanded to include the operation of aeroplanes with three and four engines.
For all twin-turbine engined aeroplanes which are flying for the purpose of public transport, with maximum authorized take-off weight exceeds 5,700 kg and certificated to carry more than 19 passengers, and requires to fly more than a threshold time of 60 minutes (calculated at OEI cruise speed in still air and International Standard Atmosphere (ISA) conditions) from an en-route alternate aerodrome;
OR
All aeroplanes with three or more turbine engines which are flying for the purpose of public transport and require to fly more than a threshold time of 180 minutes flight time (calculated at an All Engines Operative (AEO) cruise speed in still air and ISA conditions) from an en-route alternate aerodrome;
ETOPS is considered as equivalent to EDTO for twin-turbine engined aeroplanes. Operators with ETOPS Approval DO NOT require to apply for EDTO Approval for the same aeroplane airframe/engine combinations and on the same routes and to the same maximum diversion time as was authorised for ETOPS. The previous edition of CAD 513, which details the corresponding provisions for ETOPS, is considered as an acceptable mean of compliance to the requirements for EDTO for twin-engined aeroplanes. Therefore they are maintained and adopted in this document as Section II Sub-Section B.
https://www.flightglobal.com/cathay-etops-okay/10579.article
The timestamp of this article disclosed that CX A330 has already obtained ETOPS 120 in 1996.
https://simpleflying.com/etops-banned-areas/
This article gave us some background information about ETOPS, and told us one of the reasons why B747 was popular in 1980s:
Before 1985, all twin aircraft had to remain within 60 minutes of a suitable diversion airport. This is why most transoceanic operations were handled by four-engined aircraft like the Boeing 747.
The article also tells us that:
The A350XWB was the first aircraft to receive the current maximum, ETOPS 370 rating. It was the first aircraft to receive a rating higher than 180 minutes before it even entered service, showing the abundance of data available.
However, ETOPS and EDTO is one of the topics with mystery. Since the approval is case by case basis.
