Economic pressures may result in an increase of Extended-range Twin-engine Operations with longer flight times, and flights greater than 7000 nm. Multiple agencies worldwide offer flights of nearly 17 hours’ duration, including Qatar Airways’ Doha-Auckland voyage and Qantas’ Sydney-Dallas route. Recently, United Airlines announced its plan to offer a non-stop flight from L.A. to Singapore (14,000 km), with a duration of 17 hours and 55 minutes. While fuel costs of such routes have kept them prohibitively expensive, many are still in operation, and more continue to be established.
Recent approval of 330 minutes ETOPS diversion time for certain aircraft is evidence of the demand for longer flights. Currently, Boeing 777 and 787 operators are licensed to engage in 330-minute ETOPS. Benefits of these lengthier flights include more direct route planning, lower fuel burn, and fewer emissions than a typical flight path. However, concerns exist regarding inadequate rest times and overexertion for the flight crew.
- Excessive crew duty times and inadequate crew rest
- Passenger health issues (deep vein thrombosis)
- Inadequacy of support and/or medical facilities at airports to which flights may be diverted and survival after a crash in cold environments
- Future concepts such as in-flight refueling or formation flight have clear safety implications.
- Inadequate fire suppression capability for duration of ETOPS
Corroborating sources and comments
http://www.ursi.org/proceedings/procGA08/papers/GP206p4.pdf (addresses radio communication challenges)
http://innopedia.wikidot.com/in-flight-refueling-for-commercial-airliners (distant future concept)
https://www.businesstraveller.com/business-travel/2017/06/01/united-launch-la-singapore-route/ (Starting October 27th, United plans to offer a non-stop flight from L.A. to Singapore, at 8,700 miles. The flights will be 17 hours and 55 minutes long, and fly on a state-of-the-art Dreamliner.)
https://www.businesstraveller.com/features/ten-worlds-longest-flights/ (Outline of some of the other longest flights in the world, including Qatar Airways’ Doha-Auckland voyage and Qantas’ Sydney-Dallas route.)
https://www.thebalance.com/what-is-etops-282945 (Definition of ETOPS, a flight wherein an aircraft can fly areas beyond 60 minutes from an adequate airport if it’s a twin-engine or beyond 180 minutes from an adequate airport if it’s a multi-engine for extended periods of time. For three or four-engine jets, special circumstances may lead to a 240-minute ETOPS rule.)
http://www.ainonline.com/aviation-news/air-transport/2015-12-02/air-new-zealand-777-makes-first-330-minute-etops-flight (Air New Zealand flies its first 330-minute ETOPS. The arguments are lower fuel burn, less emissions, and more direct travel.)