Re: Fracturing the Pacific

Date:         18 Aug 97 02:22:18 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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In article <airliners.1997.1820@ohare.Chicago.COM>, M Carling wrote:>Chuanga@cris.com (H Andrew Chuang) wrote:
>> In article <5snqjp$cp4$1@kragar.kei.com>, <m@bang.org> wrote:
>> >From the US east coast to Asia requires a three or four
>> >engined plane because there are no suitable places for an ETOPS aircraft
>> >to land in the Arctic.

>> The B777-200IGW and the proposed -200X will have the range to do it.

>To fly from the US east coast to Asia, having the range to fly the great
>circle route will not suffice for twins because these routes are non ETOPS
>legal--there are no satisfactory landing sites within 180 minutes of a very
>large area over the Arctic.

You've said that before, and I've never really strongly questioned
it.  I finally took some time to look at the matter carefully.  Since
you focused on the Arctic, I picked three fairly northerly routes to
examine -- ORD-NRT, ORD-HKG, and JFK-NRT.  Using enroute alternates of
Fairbanks, Alaska (FAI), Petropavlovsk-Kamchatsky, Russia (UHPP), and
finally Tokyo (NRT), all three routes are easily within the boundaries
of 180 minutes ETOPS at 757 engine-out speeds.  I suspect the 777 has
a faster engine-out speed and thus a larger safety margin.  See
http://www.chicago.com/cgi-bin/gc?PATH=ORD-NRT,ORD-HKG,JFK-NRT&RANGE=180min@(FAI,UHPP,NRT).

Why UHPP?  United's Pacific/Far East Flight Supplement dated June 19,
1992 lists it as an emergency airport for both 747 and DC-10, so it
can handle large aircraft if necessary.  Alaska Airlines currently
offers scheduled service there, so it's obviously available for
commercial flights.

If UHPP is unavailable, Cold Bay, Alaska (CDB) and Yuzhno-Sakhalinsk,
Russia (UHSS) can substitute on the ORD/JFK-NRT flights.  Like UHPP,
UHSS is in UA's Flight Supplement and receives schedule service from
Alaska Airlines.  Cold Bay is listed by UA as an alternate with little
or no ground support.  It receives scheduled commuter service, but has
a 10,420' runway and thus could handle just about anything in a pinch.

Magadan, Russia (UHMM) is another possibility.  It's even better
positioned for ORD-HKG than UHPP, and does receive regular service
via Alaska Airlines.  It's not on the (old) UA Flight Supplement I
have, though, so I'm not sure if it can handle anything larger than
the MD-80s Alaska flies there.

Without considering strong winds in the far north, it looks to me as
if ORD-NRT, ORD-HKG, and JFK-NRT, flown with great circle routes, are
all doable with 180 minutes ETOPS with at least as many alternates as
are available when flying the North Atlantic under 120 minute rules.

Deeper routes pose a greater challenge.  Barrow, Alaska (BRW) is well-
positioned, but the longest runway is only 6,500' long.  Weather is
likely a problem, though the presence of ILS helps.  Assuming BRW is a
suitable alternate, JFK-HKG is well within 180 minute rules using FAI,
BRW, UHMM, and SEL as alternates.  Dropping BRW requires a more
significant diversion, but might not be untenable.

Only when you start looking at routes from the Eastern US deep into
Asia, such as JFK-SIN, does it start looking like twins are not viable
due to ETOPS restrictions.

--
Karl Swartz	|Home	kls@chicago.com
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