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In Greenland there are a number of ice runways and I have heard that it is no difficulty landing on them. One would think they would be slippery and the aircraft might slide off the runway or ground loop. However apparently that does not happen.
Are there any special considerations for landing on an ice runway? Is there an increase in minimum landing distance?
In Greenland there are a number of ice runways and I have heard that it is no difficulty landing on them. One would think they would be slippery and the aircraft might slide off the runway or ground loop. However apparently that does not happen.
Yes it does. Go to Youtube and search for "Alton Bay Ice Runway" for examples.
Are there any special considerations for landing on an ice runway?
First, understand that you are making a short field landing, NOT a soft field landing. A soft field landing (well, mine anyway!) will eat up much more runway length. Ice is hard, and you can hammer it down if necessary.
Second, do not use your brakes until under about 5 knots. Use aerodynamic braking instead. Yoke full back on the ground.
Is there an increase in minimum landing distance?
Yes! Aerodynamic braking is pretty ineffective below 20-30 knots.
First one has to understand that the gamut for ice runways is very expansive. Consider in the case of a grass runway, there is tall grass, short grass, rough surface, rolled surface, legumes (like clover) or grasses like Kentucky Bluegrass. All these factors, and more change the nature of a runway. In the arctic, ice runways are used, particularly at some outposts where bringing in paving materials is cost prohibitive, and where the temperatures are stable enough for ice.
Given the kind of ice, landing on an ice runway can be like landing on concrete, or it can be like landing on a roughly plowed, refrozen country road. So the pilot (and ground crew) observations and planning are more significant than landing at the local strip of concrete.
If the ice is a frozen lake, then having knowledge of the thickness, and nature of the ice is important. If on a river, how smooth is it? If with moving water, are there pressure ridges, etc.
From personal experience, I have a couple of stories. One time I landed at Martinsburg WV, after 1" of clear ice. I needed to land, the tanks were getting low, DC was a mess WX wise, and Martinsburg was the best option. I landed (27 or 28, I forget the exact runway), stopped on the runway, and FSS had the FBO bring the fuel truck out to fuel me. The runway had a candy coating, and was slick. After fueling, I took off from where I stood. Oh, I forgot to mention that the winds were something like 280 at 40 gust 55. It worked, and the line personnel were great.
The next story dates back to the Winter Olympics at Lake Placid. Unable to fly into Lake Placid, I did what we had done dozens of times before. Landed on Saranac Lake, and tied the plane down at my friends boat dock. A plow was handy if needed to clear a portion of the lake for takeoff.
Each of those were a higher workload than landing at an ice runway at a research facility in the arctic. But they are all doable, and just need appropriate planning, and skills.
So to prepare for ice runways, be adept at soft, short, and everything in between. And get used to the different types of ice, and what they look like, and how you will land on them.
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They analyzed runway excursions and published the "Approach and Landing Accident Reduction"(ALAR) toolkit, which is explained on SKYbary (a website fed by Eurocontrol).
The part of ALAR related to landing on iced runway is the Briefing Note 8.3: Landing Distances.
The document is a rich one, I'm extracting this part of a figure about landing distance factor:
The reference (factor 1) is without reverse thrust, and no contamination. A wet runway would require adding 40%, an iced runway adding 250%.
Although runway contamination increases rolling resistance and spray-impingement drag (i.e., drag caused by water or slush sprayed by tires onto the aircraft), it also affects braking efficiency.
The following landing distance factors are typical:
• Wet runway: 1.3 to 1.4;
• Standing-water or slush-contaminated runway: 2.0 to 2.3;
• Compacted-snow-covered runway: 1.6 to 1.7; and,
• Icy runway: 3.5 to 4.5.
While this answer focuses on iced runway, Antarctica and Greenland runways are mostly compacted snow. Runways can be prepared using low ground pressure tractors. Aircraft can be fitted with skis:
Source: William Colgan
When landing on surface with small braking coefficient, you don't want forces to be very asymmetric (reversers, spoilers, or brakes).
