What some people seem to have an enormously difficult time comprehending is that ETOPS has been less focused on engine reliability (the dispatch reliability among twins/their ETOPS-designated engine type is currently so relatively high over the quads that it's almost a negligible factor) but more about operational specifications.


I'd say the most important among them is Fire Suppression:

All 777s, A330s, and most 767s etc are designed to have the ability to chemically suppress a fire throughout the length of their cargo hold (and other areas) for a minimum of 180 minutes. Of course, the new 772LR and 773ER are designed to be able to do so for a minimum of 330 minutes.

So, how much fire suppression are quads and tris required to have, you ask? Answer... NONE!

Yep, that's it... even a half-baked carrier with a questionable safety record such as China Airlines can choose whether or it wants the "burden and expense" of installing fire suppression into its aircraft. Ya know, the same airline that also has been known to choose whether or not it wants to use an actual runway for takeoff... versus a taxiway!

Does that mean no 747s/A340s/MD11s carry fire suppression? Of course not. But I dont appreciate such carriers being given the ability to choose whether or not they want to bother with such an important factor as the capability to deal with inflight fires. Bet SwissAir wishes it had chosen to do so with its MD11s!

As for diversions:

All ETOPS aircraft must be certified of generating and sustaining either 389kt or 425kt airspeed at any point in flight with 50% power. Quads and tris only have to be certified to do so at 75% power. Only problem is that statistically... engine failures have been known to stimulate/be stimulated by other compound failures as well: it's not as uncommon as you may think to have 2 engines on the single side of a quad cut out due to fuel deprivation from a separate flow system (a la A340)

Then there's mandatory diversion with twins as well... which gives me comfort as a passenger. I'd much rather know that the aircraft I'm on is required to immediately land at the nearest available field should there be a problem; rather than give pilots the option to decide how long/where they want to go for any number of reasons.

Also, say there's an onboard fire, hijackers, or a medical emergency.... where would you rather be? Basically 120/180 minutes from a suitable port (at the most)... or 4hrs from land somewhere near Antarctica? What if TS236 had occured not with a twin 18 minutes from land... but with a quad between EZE and SYD? Easily done, considering that the A330 and A340 both could have been fitted with the same improper valve.

The list can go on and on..... just give me the increased safety of a twinjet any day.

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Faire du ciel le plus bel endroit de la terre c'est impossible sans Concorde!
~ConcordeBoy

Try the Unofficial Continental Airlines Dictionary

[This message has been edited by ConcordeBoy (edited 04-22-2003).]