Re: Fracturing the Pacific

Date:         29 Aug 97 00:53:39 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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Graeme Cant wrote:
>Karl Swartz wrote:
>> >Considering the benefits of twins, would investing in a bit of concrete
>> >not be advantagious by the airlines with large Asia-America traffic?
>>
>> That or other upgrades such as ILS at an airport which already has a
>> long runway but perhaps doesn't have very good weather.
>
>The ILS would be more important than the concrete.  I think in your
>earlier posts you over-emphasised the importance of the runway and other
>facilities compared with the weather.

I didn't think I'd written much about the runways, other than looking
at some of the more obscure airports to see if they had scheduled
service with larger jets -- which implies a decent runway, but also
other services.  Scheduled service also implies that the weather can't
be *too* horrible, since most carriers won't schedule service that
they know they'll have to cancel much of the time.

(To the annoyance of some, I preferred Western carriers.  Russian and
other former Soviet Bloc carriers may fly into places that Western
carriers wouldn't because they don't have as much winter experience,
lack the ability to land on unpaved runways, are more risk-averse,
and/or because outsiders aren't allowed to land there.)

I agree that weather is a very important factor.  I may have under-
emphasized it's importance to a degree because I don't buy all of the
arguments against Arctic ETOPS based on the unsubstantiated guess that
airports north of the Arctic circle will be innundated by snow and
thus unavailable for most of the winter.  Some of those airports have
scheduled service year 'round, with planes like MD-80s, not specially
equipped C-130s or other snow-capable aircraft.  I don't see how that
can be if snow closes the airports for most of the winter.

>An ETOPS airport MUST be available from a met viewpoint or the flight
>cannot plan to use it and must fly a longer route.

To be precise, it must be available during the times when you expect
to be depending on it, within a certain confidence level which depends
on how far in the future you might need it.  If a nominated alternate
is closed, due to fog, for example, you can still dispatch if you'll
need it in two hours and the forecast is for the fog to have burned
off within one hour.

>As I said, the ILS would be useful in lowering the minima but Arctic fog
>has the reputation (I don't know it from experience luckily, I've stuck
>to Pacific islands) of being hard to beat.

Most of the arguments so far have been based on snow, not fog.  Fog is
perhaps easier since the main investment is in the fixed cost of ILS
(assuming the fog isn't so bad that the airport is below even Cat IIIA
minima) rather than huge amounts of snow removal equipment and people
to drive the stuff.

--
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