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Old 5th Jul 2016, 11:18
  #1056 (permalink)  
compressor stall
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,295
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A side tale...

A number of years ago I was flying (true) northwest toward a particularly barren part of the Antarctic coast from high in the interior. It was seriously SKC, a brilliant day. The vast empty white terrain, bereft of mountains and nunataks, stretched to the horizon in all directions. Ground level was around 7000 feet and falling fast as it does as you near the coast.

Ahead I saw a white sheet of altostratus - around 8000'; we'd been cruising unpressurised above 10k, and were gently descending as the terrain dropped away, hunting the best winds and oxygen.

One of my pax was an aviation forecaster for an major international airline on secondment. Whiteout had obviously been covered in training and we'd talked about it at the bar a few weeks before. I summonsed the forecaster to flight deck, pointed out the cloud ahead and descended to about 7500' (the ground had dropped away further by this stage). We flew along in the bright sunshine and as we went under the edge of the cloud, the forecaster was absolutely speechless for about ten seconds then uttered various exclamations of disbelief. Even though whiteout had been covered in all the classes for forecasters, actually seeing the disorientating bowl of milk outside for real was beyond comprehension.

I pointed out in the 2:45 position some rocky mountains on the coast over 100nm away proving we weren't in cloud. After an hour or so we, along with our slack jawed jumpseater, finally reached our base under the same layer of altostratus.

Whiteout approaches as Megan points out are the "reverse" of black hole approaches. I've also done plenty of black night landings with small kero flares and no horizon or any other lights outside besides those small points of light.
A whiteout landing is just approached the same way, just with the shades reversed - like a film negative. All white outside, no sense of cloud or ground - or height- just a few black dots to tell you where the landing area is.

The major difference is the last thirty feet. At night your lights light up the ground and you flare normally. In a whiteout you can't see the ground. Even from ten feet. In extreme cases, particularly for off field landings, you set up an early very shallow rate of descent and chop the powers when something goes bump.

Last edited by compressor stall; 6th Jul 2016 at 02:10. Reason: Clarity.
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