Jump to content
Sign in to follow this  
SRobertson

Flying In The Arctic

Recommended Posts

APPLIED TEMPERATURE CORRECTION: I flew the other day (VFR) and was in the old situation of low pressure and temperature combined with flying into higher terrain. I thought it would be good to write about the realities of this as opposed to just reading about it on an IFR exam. I thought it would be a good example of real altitude change due to cold and low pressure situations while flying in the arctic.

 

Route was from a Sea Level location (40 feet) to an 1100' destination. Altimeter was 29.42. Temperature was -30C. Flew out and back at about FL030. At FL021 (the original plan), we would be at 1000' above highest obstacle enroute...maybe. The real altitude (confirmed by RADALT) for experimental purposes will be much different. Please follow: QNE for enroute is 29.92 - 29.42 (QNH) = 500 feet lower also subtract about 200' lower for temperature correction (CAP GEN pg 27). Therefore, at FL 021, the real RADALT altitide (height) over destination is 300 feet.

 

The old saying: COLD and LOW - LOOK OUT BELOW came in handy here.

 

|hope this is useful. Fly Safe. Steve

Share this post


Link to post
Share on other sites

Try finding a sun chart for setting your DG. I cannot remember off hand how to do it all something about turning towards the sun and lining the shadow up on the broom closet check the time then set your DG from the chart. Age is a bad thing some of the details are fuzzy now If I can find the chart in my old stuff I will post it.

Share this post


Link to post
Share on other sites

Another big debate is, at what temperature does icing cease in cloud. I have seen it form as low as -20, have been told that it won't form in cloud much below that. Would be interested in hearing opinions from some seasoned arctic IFR pilots?

Share this post


Link to post
Share on other sites

Try finding a sun chart for setting your DG. I cannot remember off hand how to do it all something about turning towards the sun and lining the shadow up on the broom closet check the time then set your DG from the chart. Age is a bad thing some of the details are fuzzy now If I can find the chart in my old stuff I will post it.

 

 

Thank goodness for GPS. We use the DG and line it up on the GPS track or traditional navaid if its available. I usually have to re-align every 15-20 minutes to the GPS track. The company has installed dual GPS which I think is a great idea since your alternates are so far apart and going off in the wrong direction is NOT an option.

Share this post


Link to post
Share on other sites

Another big debate is, at what temperature does icing cease in cloud. I have seen it form as low as -20, have been told that it won't form in cloud much below that. Would be interested in hearing opinions from some seasoned arctic IFR pilots?

 

I prefer not to test the theory. From my experience, ice crystals won't ice you up, but they will adversely affect visibility; especially when combined with blowing snow and/or darkness. However, ice fog or BR seems to occur at below -20 (seen it at -30). I definitely don't want to go into it as its water molecules still and my aircraft is incapable of handling it.

 

There seems to be allot more open cracks in the ocean now than what I have heard of in the past. These seem to contribute to more moisture, sea smoke rising causing BR / FG conditions at colder than -20 temperatures. Therefore icing conditions will exist in that below -20.

 

Great comments, would like to hear other opinions or experience.

Share this post


Link to post
Share on other sites

Just to add: I happened to be at a place that has just posted this strip: Note the temperature and the condition.

 

1700Z 33010KT 1/4SM -SN +BLSN FZFG OVC130 M25/M29 A2931

REBLSN RMK BLSN4AC4 SLP926

Share this post


Link to post
Share on other sites

Just to add: I happened to be at a place that has just posted this strip: Note the temperature and the condition.

 

1700Z 33010KT 1/4SM -SN +BLSN FZFG OVC130 M25/M29 A2931

REBLSN RMK BLSN4AC4 SLP926

 

Interesting for sure. Is that near sea level? Usually you wouldn't have open water at those temps, but I have seen some this year in tidal water when the ice is shifting.

 

I am interested to see what the coldest temperature that anyone has picked up ice in cloud (at altitude), enough to be a major concern?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...