High Latitude Operations

[lotuslash]

Hello all,

Any hints and insider experience on high latitude ops? Any speciality on the Global Vision regardingly? (North of 70N and South of 70S prohibited with MAP PLAN display)

Many thanks

Cheers LL

[JTF]

In the Global vision north of 70°, you simply switch from magnetic to true and make sure you have any of your screens with maps on "map" instead of "plan" mode since it is required per the AFM (I haven't tried to put it into "plan" mode over 70° to see what happens). You are also restricted from using the heading synch function while in True mode. You will have CPDLC over Alaska, Canada, and Greenland (I haven't tried it anywhere else above 70°). There are patches of HF and areas of VHF up north. Overall, it isn't much different than regular oceanic crossings.

[EESDL]

Solar Spot forecasts etc - don't be surprised if you are unable to talk to anybody for extensive periods of time (60-100-mins).
Poor GPS coverage.
Always good to know that there is a string of commercial airliners going 'polar', also knowing that there is a good chance of being unable to talk to ATC - which is meant to be pre-requisite for commercial ops?
ICAO & Authorities slow to address the issue so good luck and the odds of reaching your destination are still in your favour ;-)

[Ant T]

Poor GPS coverage.

Hi EESDL.

Interested to know whether the above comment about poor GPS coverage is from personal experience, or just repeating what you have heard/read elsewhere.

The reason for asking - I spent 12 southern summers flying over about 1/3 of the Antarctic, including flying to the South Pole, and do not ever recall having any issues with full GPS coverage.
I have read that the theoretical coverage of the GPS satellites is better at the equator and poorer at the poles, but never found it to be a problem in practice.
(Apparently, GLONASS is the opposite, better at Poles and worse at equator, but our nav kit only received GPS)

(Slight thread drift, but a similar comment on RadAlt performance - I have frequently seen references to RadAlts not being reliable over snow surfaces, but never experienced any issues at all with the RadAlts in the Twin Otters I was flying. In all the snow landings I did, everything from rock hard icy surfaces to deep soft powder snow, the RadAlt always read zero as we touched down. In fact, we used a last resort emergency blind landing technique that relied totally on RadAlt, and the skis would touch as the RadAlt reached zero.
I accept that other aircraft/radalt systems may behave differently, but do have a suspicion that reports of erroneous indications may be more due to loss of pilot's depth perception in conditions of poor surface and horizon definition)