Snow Guidelines / Braking Action Reports

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davevramp
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Snow Guidelines / Braking Action Reports

Post by davevramp »

Snow Guidelines
What are the guide lines for using a 170 in snow on regular 6 inch tires?
I have no experience on snow. Like to hear form guys that deal with snow with out skis
Any reference materials available?
Thanks
Dave
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Bruce Fenstermacher
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Post by Bruce Fenstermacher »

Wait till the plow clears it are my guidelines. :D

Seriously Dave it would depend on the ground under the snow and the type of snow. It comes down to some common sense. If you could drive your care through it your probably OK. If you think you'll get stuck keep your plane out of it.

I've been involved in operations off about 6 inches of powder over solidly frozen ground with do problem. I've been on deeper snow after the snowmobiles pack it down.

Bottom line is I'm no authority cause it just doesn't snow that often nor do I have many real places to go here in PA that the plow won't beat me to.
Last edited by Bruce Fenstermacher on Fri Feb 02, 2007 3:58 pm, edited 1 time in total.
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flyer170
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Snow

Post by flyer170 »

Dave
I have 170A 145hp with 800 tires. I have been flying off of the ice for a few weeks and just switched over to skis last week. With the wheels I was flying on basicly bare ice up untill we had a base on the lake of about 4 or 5 inches and some small amount of drifting. After the snow started to set up and I could fell some heavier resistance on take off and landings when I would hit the drifts I changed over to skis. Once I started to feel a little uneasness in my mind I knew it was time to switch. The snow can also hide pressure ridges and piles of ice around holes that ice fishermen have left. You have to keep an eye on the wind, stong winds can make large drifts in a short period of time.
I scatered some branches from our Christmas tree in the snow to help on landing in flat light. Depth perception thing. You can also approach it like flat water landing on floats with a slow steady rate of decent.
I live in N.W. WI. We have about 18inches of ice and minus 13 this a.m.
Bob
aturner
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Post by aturner »

Watch for the frozen brakes. I was out playing in the snow last weekend in my C-140, and despite little use of brakes (to turn) they were frozen on each landing. Fortunately, the brakes broke loose soon after touchdown, but there is a momentary pitching forward that gets your attention.

-Andy
-Andy Turner
C-140 2212V
C-172 7332G
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blueldr
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Post by blueldr »

Also, use caution if the landing area is rutted by vehicles or snow machines. Ruts or tracks may lead your airplane in a direction you don't want to go and brakes have little or no correcting ability.
BL
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GAHorn
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Post by GAHorn »

Snow (any contaminated surface actually) can be troublesome.
If the snow is dry, powder, not over 4" thick, on top of pavement...then it's not usually a problem. Unless the pavement has a thin 1/4" coating of ice on it before the snow fell. 8O
Or if it's on a surface that was previously plowed irregularly. (Hitting a ridge that's hidden beneath a smooth cover of new snow can lead to ground-loops.)
"Braking action" reports are always suspect as well. Sometimes even the airport authorities think they're helping you by telling you it's better (or worse) than it actually is. (They either think you really want to land there but you might be a commercial operator who needs a certain favorable report....so they report the braking action to be as good as they think you need to legally land.... .... or they think they're helping you by telling you it's worse than actual if they suspect you aren't really experienced or needful of landing there. Either way, they're wrong to report it differently than actual...or they don't actually have the proper equipment to gauge the braking action.)
And just because a previous airplane landed successfully doesn't mean things will work out as well for you as it did for them. (Were they equipped with anti-skid? Were they a much heavier airplane with the capability to break thru the ice layer?... or to compact the ice so it doesn't build up before the wheel and become an ice-dam and cause a ground-loop?
Don't mean to paint only bad pictures... just wanted to give pause to reflect on the possibilites.
Also,... only recently, over the Christmas Holidays, I was at Aspen, and the airplane that landed behind me broke a wheel due to it having been frozen to the brakes, probably as a result of taxying in or out at the previous airport that was slush-covered. Brakes heat up with use and will melt the snow they are pushing through. Then during flight, the melted snow will refreeze possibly making the wheel, brake, caliper, etc. all one nice frozen item. Upon touch-down ... WHAP!
Fortunately for him it only shredded the tire and ruined the wheel/brake assembly. The airplane continued to slide on the wheel straight ahead.

Also, consider the guidelines that are supposed to be utilized in making reports:
When reporting braking action, any of the following terms may be used:

Good
Medium (medium used to be known as Fair)
Poor (directional control/steering has become a problem)
Nil - bad or no braking action

Other, more complicated reports use various measuring devices. One type currently used is the "MU" scale. Basically, anytime they start issuing MU reports.... when they start giving numbers..... then it's bad. Don't go there.
If you'd like a copy of the scale:
http://www.faa.gov/news/conferences_eve ... raking.doc

If you read that document, you can see what kind/how much snow usually leads to poor braking. :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
bsdunek
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Post by bsdunek »

Just a reminder, from an old Smiln' Jack comic - "Smart pilots always take of their pants in the winter!" Don't want that snow and slush freezing your wheels to the pants. 8)
Bruce
1950 170A N5559C
iowa
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Post by iowa »

i flew in the winter of 1969
a few months after receiving my privates.
i was 17 and very inexperienced,
yet landed many times on the ice/snow
packed runway of Nevada, Iowa.
never had a problem.
i do remember the manager
telling me not to brake
but let the plane coast to a stop.
i'll have to check my logbook
but can't remember any significant trouble.
if me, a young pilot can do it, you can.
now 6" of snow on the RW i don't know about 8O
iowa
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1951 170A 1468D SN 20051
1942 L-4B 2764C USAAC 43-572 (9433)
AME #17747
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cessna170bdriver
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Post by cessna170bdriver »

iowa wrote:i flew in the winter of 1969
a few months after receiving my privates.
...
It's a different story when taken a bit out of context, eh? 8O

Miles
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GAHorn
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Post by GAHorn »

cessna170bdriver wrote:
iowa wrote:i flew in the winter of 1969
a few months after receiving my privates.
...
It's a different story when taken a bit out of context, eh? 8O

Miles
Yeah, I'll bet they were pretty small in the winter! :lol:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
iowa
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Post by iowa »

'It's a different story when taken a bit out of context, eh?'

am i missing s.t. here?
iowa
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1951 170A 1468D SN 20051
1942 L-4B 2764C USAAC 43-572 (9433)
AME #17747
doug8082a
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Post by doug8082a »

cessna170bdriver wrote:
iowa wrote:i flew in the winter of 1969
a few months after receiving my privates.
...
It's a different story when taken a bit out of context, eh? 8O

Miles
Iowa... you DID mention once that you are a medical doctor, correct? :lol:
Doug
iowa
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Post by iowa »

ahhhhh...
certain minds...
i took my brother and sister up,
and my mom and dad who
are pictured below.
poor quality pic but
one gets the picture of
this snowy day.
iowa
Image
Image
1951 170A 1468D SN 20051
1942 L-4B 2764C USAAC 43-572 (9433)
AME #17747
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