4 ms·

Kudos for ingenuity but from my understanding, flying over land is preferred than over an ocean as there are options available in case of emergency. So isn't th

Kudos for ingenuity but from my understanding, flying over land is preferred than over an ocean as there are options available in case of emergency. So isn't this jeopardizing flights for fuel savings?

United857 10y ago
Even over the ocean, flights in airliners are planned so they're no more than 1-3 hours from the nearest diversion point. https://en.wikipedia.org/wiki/ETOPS https://en.wikipedia.org/wiki/ETOPS
- URSpider94 10y ago
  They are nowhere near gliding range to an airport. They are hundreds of minutes of flight time from landing, in fact ...
  - Johnny555 10y ago
    But how often do airplanes glide into the ocean because they had some failure and couldn't reach land? Seems like an insignificant risk, and cutting the flight time by 10% might do more to reduce risk than staying over land.
    - kijin 10y ago
      Land routes also tends to have certain hazards that generally don't exist in the open sea, such as 8km+ mountains, idiots with missiles, and much busier air corridors around major cities. That might balance out the risk of an ocean crossing.
    - brc 10y ago
      I think there is only one case, and that was because if a hijacking. The plane broke apart on landing. It was caught on video by someone on the beach. Of course, we don't know what happened to mh17, which might have also glided into the ocean.
      - codfrantic 10y ago
        MH17 was shot down over the Ukraine, you must mean MH370.
      - deleted 10y ago
        [deleted]
    - URSpider94 10y ago
      Just came back to look at this, and saw that parent had basically replaced his original comment with a new one. The original parent said that all over-water flights were within gliding range of an emergency airport at all times -- this is obviously not true, which was what I was pointing out. Given modern aircraft design, flying over open water makes good sense.
- yread 10y ago
  Dreamliner is ETOPS-330 so it can be 5.5 hours away from an airport (I wouldn't want to be on one if an engine fails, though)
zeusk 10y ago
Yes, but flying within the gliding distance of emergency airports is acceptable (unless of course there is an emergency during early stages of climb or late stages of descent). https://en.wikipedia.org/wiki/Air_Transat_Flight_236 https://en.wikipedia.org/wiki/Air_Transat_Flight_236
- URSpider94 10y ago
  Nope. ETOPS allows planes to operate up to 180 minutes away from an emergency landing field, almost 10x the world-record glide distance quoted in this article.
  - zeusk 10y ago
    Thanks for getting technical; Multi-engine failures on a twin engine aircraft are the rarest of the rare events and so far there have been less than a handful such events in record and as such, in my comment I assumed that gliding would imply a single engine failure as is implied by ETOPS which you failed to note. The quoted flight as a result of a massive fuel leak and ignorance on the captain's part to notice fuel imbalance led to dual engine failure. Also, ETOPS itself has multiple ratings and the A330-200 (in the quoted flight) was certified for ETOPS120 or 120 minutes away from an emergency field on the flight plan and not 180. The new 300+ series rated with ETOPS180 and beyond have a higher composite content to reduce weight and perhaps more fuel efficient engines (ETOPS implies single engine failure). Source: I have a PPL and over 2500 hours in FS.
    - gcp 10y ago
      in my comment I assumed that gliding would imply a single engine failure This assumption is the problem and grandparent was very correct to point out the obvious misunderstanding that would result. Maybe this is the typical wording used by pilots, but to laymen gliding means something else.
      - zeusk 10y ago
        This being a post about airliners crossing oceans, and ETOPS being thrown about - you'd expect people would know. Without any power, airliners can't really glide much. Of the few cases of all-out engine failures, even fewer make it safely to land or water - most of which that did were at their cruising altitude at the time of failure. With only memorable exception being the hudson river ditch. In-fact, during the landing or take-off, even a single engine failure can catch the crew off guard and is among the worst case scenarios pilots are "trained" for.

United857 10y ago

Even over the ocean, flights in airliners are planned so they're no more than 1-3 hours from the nearest diversion point. https://en.wikipedia.org/wiki/ETOPS https://en.wikipedia.org/wiki/ETOPS

URSpider94 10y ago
They are nowhere near gliding range to an airport. They are hundreds of minutes of flight time from landing, in fact ...
- Johnny555 10y ago
  But how often do airplanes glide into the ocean because they had some failure and couldn't reach land? Seems like an insignificant risk, and cutting the flight time by 10% might do more to reduce risk than staying over land.
  - kijin 10y ago
    Land routes also tends to have certain hazards that generally don't exist in the open sea, such as 8km+ mountains, idiots with missiles, and much busier air corridors around major cities. That might balance out the risk of an ocean crossing.
  - brc 10y ago
    I think there is only one case, and that was because if a hijacking. The plane broke apart on landing. It was caught on video by someone on the beach. Of course, we don't know what happened to mh17, which might have also glided into the ocean.
    - codfrantic 10y ago
      MH17 was shot down over the Ukraine, you must mean MH370.
    - deleted 10y ago
      [deleted]
  - URSpider94 10y ago
    Just came back to look at this, and saw that parent had basically replaced his original comment with a new one. The original parent said that all over-water flights were within gliding range of an emergency airport at all times -- this is obviously not true, which was what I was pointing out. Given modern aircraft design, flying over open water makes good sense.
yread 10y ago
Dreamliner is ETOPS-330 so it can be 5.5 hours away from an airport (I wouldn't want to be on one if an engine fails, though)

zeusk 10y ago

Yes, but flying within the gliding distance of emergency airports is acceptable (unless of course there is an emergency during early stages of climb or late stages of descent). https://en.wikipedia.org/wiki/Air_Transat_Flight_236 https://en.wikipedia.org/wiki/Air_Transat_Flight_236

URSpider94 10y ago
Nope. ETOPS allows planes to operate up to 180 minutes away from an emergency landing field, almost 10x the world-record glide distance quoted in this article.
- zeusk 10y ago
  Thanks for getting technical; Multi-engine failures on a twin engine aircraft are the rarest of the rare events and so far there have been less than a handful such events in record and as such, in my comment I assumed that gliding would imply a single engine failure as is implied by ETOPS which you failed to note. The quoted flight as a result of a massive fuel leak and ignorance on the captain's part to notice fuel imbalance led to dual engine failure. Also, ETOPS itself has multiple ratings and the A330-200 (in the quoted flight) was certified for ETOPS120 or 120 minutes away from an emergency field on the flight plan and not 180. The new 300+ series rated with ETOPS180 and beyond have a higher composite content to reduce weight and perhaps more fuel efficient engines (ETOPS implies single engine failure). Source: I have a PPL and over 2500 hours in FS.
  - gcp 10y ago
    in my comment I assumed that gliding would imply a single engine failure This assumption is the problem and grandparent was very correct to point out the obvious misunderstanding that would result. Maybe this is the typical wording used by pilots, but to laymen gliding means something else.
    - zeusk 10y ago
      This being a post about airliners crossing oceans, and ETOPS being thrown about - you'd expect people would know. Without any power, airliners can't really glide much. Of the few cases of all-out engine failures, even fewer make it safely to land or water - most of which that did were at their cruising altitude at the time of failure. With only memorable exception being the hudson river ditch. In-fact, during the landing or take-off, even a single engine failure can catch the crew off guard and is among the worst case scenarios pilots are "trained" for.