Airplanes on skis ? (1 Viewer)

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In Rocky Mountain National Park in Colorado, plow operators are dealing with some of the deepest snow seen in years. Above, 23 feet of snow on Trail Ridge Road.
From Record Snowpacks Could Threaten Western States (Published 2011)
The last storm we had a few weeks back, dumped well over 16 feet of snow in the Sierra Mountains.
Not sure what the total accumulation is at the moment, but it's similar to that photo!
 
Here's the end result of one...note where one set of main gear ended up, just next to the rear-mounted engine:

View attachment 655064

This one slid off the runway...but studded tyres wouldn't have made a blind bit of difference.

Here's the write-up: United Airlines Commuter Jet Slides Off Runway, Rips Off Landing Gear in Rough Maine Landing


The only approach I've seen, other than fitting skis, is using oversized tyres. I've only seen this on small, fixed-undercarriage aircraft that have a tailwheel. The larger tyres perform a similar function to the skis by spreading the load more:

View attachment 655066
Clear advantages of rear engined planes.
1 No time wasted looking for landing gear in snow.
2 A handy place for carrying spare wheels is provided, like other off roadsters.
 
Part of the problem with wheels is that they don't cope well with side-forces. That's typically not a problem in routine operations because, short of other factors (e.g. brake locking), aircraft seldom end up going sideways. When landing on snow/ice, the possibility for an aircraft going sideways is much higher, particularly if there's a crosswind. As noted in the UA crash highlighted above, a wheeled undercarriage often can't cope with the sideways force applied during a skid and ends up failing. This will be even more likely if the aircraft runs from hardened snow/ice onto softer snow, as the skidding wheels will dig into the soft stuff. Since the ski rides over the snow, skid tolerance is increased, with the likelihood that the aircraft won't be badly damaged even if it starts going a little sideways on the landing run.
 
Here's the end result of one...note where one set of main gear ended up, just next to the rear-mounted engine:

View attachment 655064

This one slid off the runway...but studded tyres wouldn't have made a blind bit of difference.

Here's the write-up: United Airlines Commuter Jet Slides Off Runway, Rips Off Landing Gear in Rough Maine Landing


The only approach I've seen, other than fitting skis, is using oversized tyres. I've only seen this on small, fixed-undercarriage aircraft that have a tailwheel. The larger tyres perform a similar function to the skis by spreading the load more:

View attachment 655066

I don't think the United Express slid off the runway... I tried to find an aerial shot (have seen it) that makes it a bit more obvious. This one shows it a bit better.
 

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I wondered if there were "fins" or something for more straight line stability when sliding down a long narrow skating rink at illegal highway speeds.
 

I don't think the United Express slid off the runway... I tried to find an aerial shot (have seen it) that makes it a bit more obvious. This one shows it a bit better.

Fair enough...I was just going off the original report I found. However, it does nicely illustrate why a wheeled undercart and snow aren't a particularly good combination. :)
 
I wondered if there were "fins" or something for more straight line stability when sliding down a long narrow skating rink at illegal highway speeds.
Actual skiis (for people) have "tuning" for various applications.

The downhill skiis have an aggressive edge that helps keep the skiis going in the direction they are pointed.
Amateur night skiers have a similar tuning to the edges, as the snow gets "crusty" as evening temps start freezing the top of the snow.
 
The last storm we had a few weeks back, dumped well over 16 feet of snow in the Sierra Mountains.
Not sure what the total accumulation is at the moment, but it's similar to that photo!
I saw that in our national press with very similar pictures, I was actually searching for some from near here just after the war, people looking down on a locomotive in a corridor of snow. Or some very unspectacular pics of the land covered in perfectly flat snow, 'cept underneath is a field full of sheep surrounded by dry stone walls and a stone shelter.
 
I have this book by Alex Crawford about 263 Sqn's ops with Gladiators in Norway:

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For a period in April 1940, the Sqn operated from a frozen lake. The RAF Gladiators retained their wheeled undercarriage throughout their Norwegian adventure. Alas, the many personal anecdotes don't seem to include much mention of how they operated on snow and ice. However, one aircraft was written off as an undercarriage leg was ripped off during their first landing on the lake. I'll scour the book in more detail to see if I can uncover any additional details.
 
I bet the contact patch on that wheel is less than my shoes, possibly smaller than the heel on my shoes.

Exactly...which is part of the problem in comparing an aircraft to a rally car. Aircraft tend to be much heavier than rally cars...even a lightweight like a Fokker D.XXI weighed in at over 4,300lbs, with virtually all the weight on the main undercarriage (i.e. two points of contact with the ground). A modern rally car weighing 3,000 lbs but sitting on 4 modern, wide tyres, will apply far less pressure on the ground than any WW2 fighter aircraft.
 

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