bakersdozen
Posts: 186
Joined: Mon Nov 20, 2006 12:24 pm

Polar Route (pre-clearance Checklist?)

Wed Dec 19, 2007 9:06 pm

Regarding the flying of aircraft over the arctic on the "polar route." I was reading an article in AC's enRoute magazine which said the polar route can't always be flown due to cold weather and other factors.

Is this true anyone know what these factors are? I would have assumed that the normal -70 temps of flying at 40 000 feet wouldn't be much worse flying of the arctic.

Anyone know some of the checklist variables before a flight is allowed clearance over the arctic?
 
boysteve
Posts: 887
Joined: Sun Apr 25, 2004 7:02 am

RE: Polar Route (pre-clearance Checklist?)

Wed Dec 19, 2007 9:58 pm



Quoting Bakersdozen (Thread starter):
Is this true anyone know what these factors are? I would have assumed that the normal -70 temps of flying at 40 000 feet wouldn't be much worse flying of the arctic.

The atmosphere is thinner at the poles, flying at 40,000 feet on a polar route would put the aircraft in a different layer of the atmosphere compared to normal. Is this a factor at all?
 
Thrawn
Posts: 45
Joined: Fri Mar 15, 2002 2:24 am

RE: Polar Route (pre-clearance Checklist?)

Wed Dec 19, 2007 10:12 pm

The fuel freeze point has to be considered as at some airports in the USA they only have JET A (-40 C)
and not JET A1 (-47 C)
So the fuel freeze point is checked before flight to establish the freeze point of the day

You don't want the fuel freezing in the wings in flight
 
LawnDart
Posts: 861
Joined: Fri May 20, 2005 11:33 pm

RE: Polar Route (pre-clearance Checklist?)

Thu Dec 20, 2007 2:18 am

As pointed out, fuel freeze is a concern of polar flying...pockets of very cold air tend to form in the far northern latitudes, and flying through it can cause problems with your fuel.

Solar radiation is another issue...I've never seen a problem with it, but it can happen (can cause health problems with long exposure, communication problems).

And that's the third issue I can think of...you can loose communications.
 
SoBe
Posts: 184
Joined: Fri Oct 08, 2004 12:11 am

RE: Polar Route (pre-clearance Checklist?)

Thu Dec 20, 2007 7:41 pm

Among other things, the availability and suitability of alternates is an issue. The alternate has to have facilities to care for the crew and passengers.

Here is some info on Polar ops http://www.boeing.com/commercial/aer...zine/aero_16/polar_story.html#fig1