Landing on snow

[Grum]

:confused: There is a similar thread on 'Questions' i think but i don't fly a large jet and so would like to get advice abit more relavent to me. I fly a kingair and had the pleasure of arrriving at Shoreham the other day with the surface conditions being 50mm of DRY snow braking action poor. No one had landed or taken off that day.

I flew a low runway inspection to make sure that i could see where the displaced threshold started. I could see it and decided to fly the circuit and land. I had never landed on snow but had landed on slippery mud, so if the aircraft felt at all twitchy i would go around. I approached low and slow, condition levers high idle for max reverse, feet off the brakes, landed and and came to a halt pretty abruptly with tons of runway to spare. :p

First off, how would a field like EGKA determine braking action poor? No one had driven on the rwy. Just the fact that they said it was poor should that have stopped me from even contemplating the approach? Nothing in the ops manual.

What would you have done?

Secondly, would you use type 4 deicing liquid on a kingair (vr95)? It was all they had at a particular arfield. I've heard from some people that if you just have a thin film of frost on the aircraft then don't worry about deicing. I know what is advisable but what is done in practice? A jet pilot was laughing at me the other day for trying to scrub frost (1mm thick) off my wings the other day. Who's the fool?

There's alot to be said for sitting around the aeroclub bar to discuss this type of stuff.

Any help would be great.:O

[transilvana]

As a jet pilot, if I have ice doesn´t matter what thickness I apply deicing, ice is not uniform on all the the surface of the wing so you may get diference on lift on both wings. if you download from the NASA the icing course you will know why, it´s very interesting and you will have no doubt what to do next time.

http://aircrafticing.grc.nasa.gov/courses.html

[Johnny Redd]

Any Ice, Dont think Twice, De-Ice.........

Dodgy video, excellent sentiments, nuff said...................................

As far as Type IV fluid goes as far as I know there would be no problem in using this on a turbo prop type like the King Air (unless specifically limited in the AFM) but there could well be a need to increase the rotation speed.

Type 4 is a thickened fluid which will stick to the airframe until it reaches its "shear speed", which in most cases is a medium size jet VR (probably about 100 knots or more). Therefore you will have to check what speed this is for the fluid type and consider the performance issues such as increased TODR due longer ground run.

Finally, if a thickened fluid is applied to an aircraft with unpowered flying controls or a T-Tail (and the King Air has both) then the airframe will have to be jet washed with hot water generally within 3 days to stop the fluid refreezing in the "aerodynamically quiet" areas on the tail at a later date. And that really would spoil your day :eek: .

Phew...........................................

[Stearperson]

Type IV de icing fluid is usually used to protect against falling precipitaton freezing to the surfaces.
Type I and II are intended for de icing when there is not falling precip.
I know this does not answer your question precicely and I do not really know if type IV for is safe for a lower speed aircraft.

A braking action report usually must be generated by an aircraft that has used the runway. I would not worry too much about dry snow as it usually provides fairly good braking action. Especially if compared to Ice or slush.

You should NEVER EVER takeoff with any frost on any flying surface.
At least two Challenger crews have discovered this in the last couple of years.

You are doing right by de icing with whatever means available.
You are not the fool.

[ahramin]

I fly a King Air in Canada.

As you discovered 5cm of snow is usually no big deal. The biggest worry is freezing up the brakes (not a problem on the 90). Staying off the brakes is the biggest defense against freezing brakes. However when needed light-medium braking is effective on dry snow.

My understanding is also that braking action comes from previous aircraft, though here friction index readings from a truck are more common. Braking action is only used with rapidly changing conditions.

Type IV fluid is perfectly acceptable on a King Air as long as you make sure you don't rotate until you have reached the shear speed. There is a huge caveat though in that type IV is not a good de-icer. Heated type IV will work fine for de-icing a little ice in warmer temperatures but when you get to -25 C or less with lots of ice or snow you really should de-ice first with type I or II to clear your airframe, then protect it with the type IV.

As for frost on a King Air. Unlike many faster airplanes, if you ask a King Air to fly with a coat of frost it will do it for you as long as you don't do anything else stupid. But why would you? Anyone who says that a King Air is going to crash and burn because of a simple layer of frost needs to learn more and talk less. But is the frost the same on both wings? Was one wing in the sun and one in the shade right before the sun went down? Why take a chance with something so high risk? How hard is it to get frost off an airplane? 20 minutes and a broom should pretty much cover it. I have never had to spend more that 30 minutes clearing off frost or snow from an aircraft. Well worth the peace of mind. I wouldn't pay any attention to someone scoffing at a guy for de-icing his airplane.:bored:

One last thing about King Airs: For the 200s, 300s, and 350s, the T-Tails are a killer. They must be deiced properly and are quite tall. In icing weather, when i call ahead to wherever i am going to check fuel prices, i also check on availability of some method of getting up to the tail. The tail must not be skipped even if the critical lifting surface (bottom) is clear.

[Grum]

All good stuff, thanks.

I'll think about carrying a broom on board for DIY de-icing when none is available. I have only come across the use of Type IV fluid once, so i guess it is not the norm for deicing as you all say. I also found it virtually impossible to see out the windscreen with this stuff sticking to my aeroplane. The wipers just smeared it around to make the situation worse. Lessons learnt the hard way. :)

[His dudeness]

T-Tail...ahramin is absolutely right.
I discovered that more than 10 years ago and I´m not proud of it. We parked outside and had loose snow on the aircraft, which I removed from the wings with a broom. Then, beeing a smart ass, I figured the snow would simply blow off the tail (it was really loose snow on the wings). We then had to wait behind a row of jets for quite a while...on takeoff roll the aircraft rotated itself passing roughly 90 knots and went steeply up. We had to press on the wheels and even had to reduce power a little in order not to stall. We relanded and "discovered" a layer of frozen snow that had built up in front of the elevators.
This was the last time in my life that I didn´t check a T-Tail prior departure when the slightest doubt exists.
I landed the KA several times in relatively high snow. The biggest problem I encountered was on a wide runway, that had been cleared in the middle and the piles on either side made loose the sight of the edge lights in nighttime. With no middle markings visible and no CL lights that was rally scary.
Some KA´s have heatet brakes, is definetely an option one can have on a B200 (we had it).
One last thing: we used fly to a snowy place in poland with 2 B200 regularly. One had a dark brown painted tail and wings, ours was the usual white one. Whenever it had snowed and then the sun came out, the brown airplane was free of ice and snow and we had deice.....

[ahramin]

The heated brakes are almost more trouble than they are worth. Operated properly they can make things easier but it is still very possible to freeze up brakes even with the brake de-ice.

[reynar]

One other suggestion when operating on a snow covered surface, when parking A/C leave parking brake OFF till brakes cool and on departure leave your landing gear down for a longer period of time to ensure all slush and snow are blown off .

[SnowPilot]

Something you also might want to do is cycle the gear on departure. This ensures that the squatch switches stay free. You'll have a higher squat switch failure during the winter especially on the 90-200 series due to their location and where the props are throwing stuff up.

Remember allways operate with the ice vanes down. Give yourself plenty of margin on the speeds.

[compressor stall]

His dudeness
Reference your brown kingair wings.....that's why our wings are this colour!
http://www.remoteadventures.com/webpics/_DSC3950.jpg