Date: 19 Aug 97 04:14:05
From: kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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>Assuming all the alternates you list are available year-round (I'm
>particularly doubtful about UHMM and BRW), then all of these routes can be
>flown ETOPS. The critical one is BRW without which all these routes must be
>flown well away from the great circle route.
I agree that BRW is dicey. Let's try a different set, trying not to
go too far out on a limb:
FAI Fairbanks, Alaska, US
CYRB Resolute Bay, Northwest Territories, Canada
BGTL Thule Air Base, Greenland
ENVA Trondheim, Norway
LED St. Petersburg, Russia
MMK Murmansk, Russia
OVB/UNNN Novosibirsk, Russia
GDX/UHMM Magadan, Russia
Hopefully we can agree that Fairbanks is viable. Others have noted
Resolute Bay as a viable alternate; it's nearly redundant with Thule,
which UA lists as an emergency airport and which reportedly has more
than adequate facilities. Trondheim is already used by UA as an ETOPS
alternate.
Moving into Russia, St. Petersburg, Murmansk, Novosibirsk, and Magadan
all receive regular scheduled service. I assume, perhaps erroneously,
that if it's reasonable to plan to fly to an airport, it's reasonable
to use it as an alternate. St. Petersburg and Magadan both receive
scheduled jet service by Western carriers throughout the year (e.g.,
FRA-LED on LH using 737-300, ANC-GDX on AS using MD-80). The only
Western service I could find to Murmansk was Finnair (AY) flying
HEL-MMK with an ATR-72, though Aeroflot takes a Tu-154 in there so it
can handle a reasonably large aircraft.
Novosibirsk is perhaps a long shot. I couldn't find any Western
carriers going there, but Aeroflot has plenty of flights including at
least one with an Ilyushin-86. If they can handle that turkey, any
self-respecting Western twin should have no problem whatsoever.
With these eight airports, nearly the entire area above the Arctic
Circle is 180 minute ETOPS territory, with several options for all
but a few small pieces. The only no go area is northeast of
Novosibirsk. The JFK-SIN great circle route is just barely east of
this area, and IAD-HKG is slightly west of it. JFK-HKG and BOS-HKG
pass right through it, though, and obviously some other interesting
routes would too. Either of the following airports would provide
the needed alternate for this area:
DKS Dikson, Russia
IKS Tiksi, Russia
Both are on the north coast of Russia and thus probably have pretty
nasty weather. Aeroflot doesn't even fly there, which is another bad
sign. On the other hand, they appear to be fairly strategic locations
from a military standpoint and thus may have considerably better
facilities than their small size and remote locations might otherwise
suggest. Even if they're marginal, the Russian thirst for hard
currency might be enough for them to make any necessary upgrades if
it means a revenue stream from overflight fees.
One other possibility is Yakutsk (YKS) which has a major new airport
which is probably a suitable alternate. Unfortunately, it's not quite
far enough north, so for a short time DKS and/or IKS or some other
airport(s) near the Arctic Coast are needed, but reducing the time for
which they are needed would improve the odds of cancellation due to
probable unavailability of enroute alternates.
While some Arctic ETOPS routes appear to be at best dicey until one
or more Russian airports on the Arctic Coast are improved, assuming
they aren't already adequate, it seems to me that many polar routes
are quite doable under ETOPS rules. If faster cruise speeds imply
faster engine-out speed (not necessarily true), then the 777 makes
it even easier since I was using the 757's engine out speed. This
may also give the 777 an edge over the A330.
>Also, in the unlikely event of a B777 or A330 diversion to BRW, the aircraft
>might have to depart empty due to the short runway. Then smaller aircraft
>would need to be brought in to collect the pax.
777s flying SFO-LHR have occasionally departed on 1R, which is only
8,901 feet long. BRW-FAI is only 503 miles, so while the 6,500 foot
runway isn't very generous, I don't think it would be that big of a
problem given the modest range requirement. Obviously a longer runway
would be preferable if available.
>Agreed. JFK-HKG without BRW as an alternate might or might not be untenable.
>My guess is that it would only be profitable using a low-density aircraft,
>and only putting full-fare pax on the nonstop ...
Flying JFK-HKG via N78 E164 keeps the flight within 180 minutes of
either Fairbanks or Magadan (at 757 engine-out speeds, with none of
the other alternates mentioned above required) yet adds only 8 miles
(0.099%) to the direct distance. Trivial compared to the 0.8%
increase in flight time (roughly proportional to distance) for a 757
flying London-New York with a 120 minute rule-time and using Shannon
or Prestwick, then Keflavik, then Gander or Goose as alternates.
>JFK-SIN (like JFK-BKK) has a great circle route going round the other way,
>north of Scandanavia and Siberia. However, the route would probably be flown
>eastbound in each direction to take advantage of prevailing winds. To be
>ETOPS legal would require large deviations from the great circle routes,
>which might be advantageous if flown eastbound in both directions. Please
>note that this paragraph is highly speculative.
JFK-SIN does not appear to need any deviation. Alternates are, in
turn, Resolute Bay or Thule, then Murmansk, then Novosibiersk or
Yakutsk. Between the minor east/west component in the routes and the
high latitudes, I wonder how much wind benefit could be obtained.
--
Karl Swartz |Home kls@chicago.com
|Work kls@netapp.com
|WWW http://www.chicago.com/~kls/
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills
