Re: ETOPS question on Aer Lingus A330

Date:         22 Nov 97 20:41:26 
From:         Seth Dillon <bdillon1@mindspring.com>
Organization: Delta Air Lines
References:   1 2 3 4
Followups:    1 2
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C. Marin Faure wrote:
> In article <airliners.1997.2653@ohare.Chicago.COM>, showie@uoguelph.ca wrote:
> > Seth Dillon <bdillon1@mindspring.com> wrote:
> > >As you may know, each aircraft has what is called a Minimum Equipment
> > >List ... It is in the carriers best interest to repair the aircraft as soon
> > >as possible as non-ETOPS routing adds considerable time and expense to the
> > >trip.
> >
> > Just curious - what are the new requirements if a flight is downgraded to
> > NON-ETOPS? Must they be less than 60 minute flying time from an airport
> > throughout the flight?
>
> Not necessarily. Depending on the airline, airplane, route, and weather
> conditions at the alternates, they may drop from 180 minute ETOPS to 120
> minute ETOPS or even 90 minute ETOPS.  This may significantly affect their
> route, or their ability to fly non-stop to their destination, but it does
> not automatically revert them to the 60-minute rule.

A carriers fleet or part of the fleet may be downgraded from 180 to 120
or 90 based on operational performance of the fleet.  In some cases a
carrier may be able to operate  one a/c type at 180 but only have 120
min authority on another a/c type.  This is usually due to reliability
problems on one type that are not present on another.  It may also
reflect differing operating experience levels with the two types.

I do not know of any regulatory mechanism inplace that would allow an
individual aircraft within a fleet to be partially down graded (180 to
120 or 90).  The individual aircraft are either ETOPS or non-ETOPS,
based on all ETOPS required equipment and systems being operational.
The carrier is approved to fly an ETOPS aircraft at 90, 120 or 180 based
on the carriers historical reliability data(with that specific
airframe/engine configuration) and operational experience.  Acarrier
operating 767-300ERs with PW4000 engines may have worked up to 180 min
authority, but if they added some 767-300ERs with CF6-80C2 engines they
may be restricted to 60, 90, or 120 until there is enough reliability
data assembled to satisfy the carriers NAA that 180 is justified.

The only possible scenario I can imagine is if an ETOPS aircraft had to
replace a 180 min cargo fire suppressant bottle with one of less
capicity.  This however raises a whole bunch of other issues I won't go
into here.

A 180 min ETOPS flight could be rerouted to a longer route if a suitable
alternate was down due to weather or other reasons, but that would not
be a reflection of the ETOPS status of the aircraft.

-Seth