De-icing fluid
 

Is there any reason why we can't use automotive de-icer fluid on the metal wings of a GA aircraft?

From a pratical point of view its proberly a bit runny and won't stick to the wings like its meant to.

Also if you are at a controlled airport they have all now moved onto eviromentally friendly fluid. The up shot of this move is that you will go through brakes and shimmy dampeners at 3 times the rate as summer. The stuff eats landing gear.

But as they are using this type of fluid if SEPA do a fluid check in the outflow sump and find horrible de-icing fluild there may be a bit of a witch hunt to find out who has been using it.

MJ

De-icing, effects the stall speed
 

Hi there!

Anti-icing fluids are supposed to stick to the wing for a period of time right?

But can't even the anti-icing fluid itself create the stall speed to be lower. Because it is said that all contamination on the wings even small ones have effect on flight performance. So then when anti-icing fluid is supposed to be stuck on the wing. Won't the fluid itself also have an affect on flight performance?

Thanks!

I think you probably meant to say that contamination raises the stall speed.

Assuming that was your intention, it is true that any form of contamination contributes to some extent to a change in the stalling characteristics of an aerofoil.

Ice to a much greater extent than a soft smooth fluid.

2D

for big things...

Type 1 fluids - glycol based no thickener, normally diluted with 50% water and heated....relatively short holdover times (until you have to do it again)

Type 2 / 4 - glycol and water with a thickening agent.

i.e. they protect you on the ground but should flow off during the takeoff run to give a clean wing when airborne.

CAA have recently published an AIC about anti-icing / de-icing, AIC 105/2003 (Pink 61) 11 December
:ok:

There is also a marked difference in the amount of de-icing which some people carry out.

1. Some go to whole hog and do the whole lot including air frame.

2 .Some just go for the flight surfaces

3. Some the flight surfaces to just past the peak of the aerofoil.

4. Let410 operators who brush the worst of it off and go flying :ooh:

And with the above there seems no connection between experence, qualifications or aircraft type. Proberly a bigger link is tightness of wallet and can't be arsed factor.

Personally if its a frost i will do 3 on the wings and the whole of the tail plane.

Anything heavier than that number 2. And brush the rest down.

And maybe the cowling so bits don't blow back on the TO roll.

Safest of course is number 1 but as a drum of the proper stuff costs 90quid plus flying instructors are under alot of pressure not to do it. My method seemed to be a compromise which I was happy with and the boss.

The other method which shouldn't be used is stick an extra 5 knts on your speeds and go for a 15min flight. This i have seen a few times and is highly daft. It will work for years but one day it will bite your bum.

MJ

M_J, cost is, of course, one of the reasons for posing the question. That and the lack of any de-icing facilities.

I do appreciate that a can of de-icer costs an arm and a legs, but the cost of not deicing the aircraft properly can be both arms, both legs and all the interconnected parts.

As a can of aerosol of de-icer costs 70p, I have no hesitation about using the entire can to get all the surfaces clean, coupled with the use of a rubber scraper to remove any slush/water.

What I want to know is is there any reason not to use automotive de-icer, such as paint damage, deteriotion of rubber seal, crazing of perspex, etc etc.

If there isn't a good reason, this poses the question, 'Why don't flying Clubs use it?

Wouldn't have thought so. Paint or seals arn't affected on your car. And you can try it on any old perspex before using it in anger.

If you are going down that route why don't you buy a B&Q garden pump sprayer. Then get a bottle of windscreen wash and mix it with warm/hot water then spray it using the pump sprayer.
And if that works out expensive a bottle of meths would do the trick as well. Woudn't use a salt solution though due to corrosion.

Just watch out you don't de-grease important bits.

It would be alot better than fannying around with a spay can.

As for flying schools, its a legal thing because we are on Public C of A and have paying punters on board. Although I am sure some out of the way schools will do it.

MJ

For small private aircraft why not be sensible?

If its going to cost an arm and a leg to do it properly, forget it. The cost far outweighs the runnings costs. Cancel the flight.

Or, rather than use some cowboy method, why not wait until it goes naturally in the sunshine, otherwise cancel.

Why mess up a lovely airframe with some micky mouse system for the sake of an hours flying!

Its knowing when not to go flying that is sometimes the better bet!

Not sure I can agree with that, UV.

You're making the assumption that any flight which isn't in a Public CofA aircraft is purely for fun. What if the pilot has a business meeting to attend, though, just as an example? Or, not quite so critical, but maybe you have pax who will be disappointed?

I'm not for one moment suggesting that anyone should even consider flying in conditions when it's not safe. But there's no reason why we shouldn't put a bit of effort into making conditions safe, rather than just binning the whole flight because it's too much effort to use a little de-icer.

(Personally, though, I'd agree with you - if it's an hour-long jolly because I feel like flying, the effort of de-icing probably isn't worth it. But that's only if it's just an hour-long jolly purely because I feel like flying.)

FFF
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The B&Q pump wasn't my invention. I think you will find that alot of charter companys use this method.

Anyway I have a much lower tech method than that. Unfortunatly my bladder isn't big enough to do both wings.

MJ

I am very well aware of the costs of operating an aircraft. However, there are some things you should not skimp on - your life, for example. I don't know the ins and outs of the science of de-icing fluids, but I personally wouldn't use anything other than that the officially approved and tested.

36 years of using the correct stuff means that I am stll walking around. If you use a cheap alternative, who knows what the effects will be?

A few years ago I was ferrying a Yak 50 to UK and, after night stopping in Gdansk (-20 over night), awoke to find the said Yak all iced up. I asked one of the handlers about de icing fluid. He looked at the Yak, went away and came back 10 minutes later with 5 x litre bottles of car anti freeze. 2 cans per wing, 1 for the tailplane and 20 minutes later I was on my way with a de iced Yak 50.

Reichman

FJJP if you are flying VFR all you require is that your flight surfaces are free from icing. How you do it isn't really defined in stone.

Flying VFR I can't really see a problem AS LONG as there is nae ice on the surfaces.

MJ

MJThe one drawback with your low tech method is that you certainly wouldn't be able to do the tailplane (plus, I'd be interested if you could reach the top of the rudder!! ;)). I suppose you could always get a pax to do the port mainplane (although some engineering work may be required if it were a female pax! ;)). :D

When at a UK club during training, I've certainly been provided with a B&Q garden sprayer to de-ice the aircraft. I've also been encouraged to position the aircraft to use solar heating to best effect!

A related question
 

Yesterday morning, it was beautiful flying weather, but bl00dy cold!

I left my house, de-iced my car, and drove to the airfield. The ground was frozen solid as I had my aircraft pulled out of the hangar. I pre-flighted, there was no ice (not surprising since the aircraft had been hangared), so I climbed in and turned the key. The aircraft wouldn't start in the cold weather.

An hour later, I returned with another group member, who was armed with a heater. We pre-heated the engine, after which it started fine, so I was able to fly. Woohoo!

Except that, in the hour-and-a-half or so while I was trying to get the engine started, a decent (1/2mm or so) layer of rime ice had formed on all of the flying surface.

Question 1: Where did this ice come from? The aircraft had come from a warm hangar - it would have been warmer than the dry ambient air, and so should not have caused any condensation to occur. As the aircraft cooled down in the outside air, it would never have cooled below the ambient air temperature. In fact, ice formed even on those surfaces where the morning sun was shining. Neither I, nor anyone else who was there, could explain the reason for the ice forming.

Qeustion 2: What would have happened if the engine had started first time? I'd have gone flying with no ice on my wings, and remained clear of visible moisture... would ice still have formed? Would it have affected the flying characteristics of the aircraft significantly? The ice, by the way, was invisible (white rime-ice on a white aircraft) unless you run your hands over it, so I would not have noticed it forming, and would not have been able to return for a precautionary landing, nor make any compensation for increased stalling speed, etc.

I have to admit to being slightly worried by this, as well as confused.

FFF
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Don't use anti-freeze if you park on grass!

I have a little Land-Rover fire engine and one year I was advised to put anti-freeze in the water tank with the the idea of keeping the pump seals wet without risk of frost damage.

In the spring, normal practice is to check the pump by playing the hose over the lawn. Result: a brown lawn!

An idea we're toying with is wing covers. That way the ice will (hopefully) form on the covers rather than the wing. Also if we have them in a dark colour there'll be solar gain to warm everything up that much quicker if the sun comes out. Should also make washing the plane easier. We already have a cover over the cowl, screen and windows and never get ice forming on them.

FFF
Possibly what happened is this:-
The air was super-cooled. It was cold enough for the moisture to condense out but there was nothing for the ice crystals to grow on. You provided it.

Mike

Aye your right CB the tail wing on a tomahawk needs plenty of boost pressure.

But this method has been effectively been used by 3 IR students to de-ice a cougar. Must admit there was words said by the tower when we taxied out.

Also the mushroom cloud appearing above the plane under a apron light when we shut down for a crew change was also noted by the tower.

Mind you the student who thought it was funny to taxi forward when the instructor needed to go while holding during a stop -pee and go and then request the runway lights be turned up full.... Brave lad that one :D

For those that haven't done a IR it is very possible you can end up sitting in a freezing cold plane being bounced around for 5 hours.

MJ