De-Ice Question

[Doc]

Headed down to PVR recently on Sun Wing. Great job BTW everybody. Always enjoy flying with their crews.

Share with me your de-ice requirements. Temps were just below freezing, about -5 or -6. No precipitation. Aircraft was very "clean". No surface ice noted anywhere (by me at least, and I've been around a while....some say long enough, already) and yet the aircraft was de-iced. Couldn't figure out why, so educate me.

Also....it was a bizarre aircraft. 737 800 from Germany. Must be a short range commuter option package? Tightest leg room ever, and the seats didn't recline??

[whipline]

Hi Doc, hope you enjoyed your vacation. Just a guess about the de-ice. Quite often we pick up ice on the leading edges during approach. The wing anti ice system doesn't have any ducting on the outboard slats or the inner leading edge flap. Also there is no anti ice system for the tail section. I personally find it odd we can land like that but can't depart like that...? If it wasn't frost that's my guess.

Secondly all seats recline except row 15. We sell it as extra legroom but in my opinion the worst row of seats on board.

Whip

[BeechjetYKZ]

All of the SWG planes are configured as 189Y. The first five rows on the right side and the first two on the left are configured to have extra pitch. The two exit rows are both sold as premium as well however as noted, the first exit row (row 15) does not recline as it would intrude on the exit door in the row behind it. Sunwing has two "German" planes, one has an all yellow paintjob and the other is white with orange stripe/tail section. IMO the best interiors are on the Thomson (UK) and TUIfly (Germany) planes.

[Doc]

Hi Doc, hope you enjoyed your vacation. Just a guess about the de-ice. Quite often we pick up ice on the leading edges during approach. The wing anti ice system doesn't have any ducting on the outboard slats or the inner leading edge flap. Also there is no anti ice system for the tail section. I personally find it odd we can land like that but can't depart like that...? If it wasn't frost that's my guess.

Secondly all seats recline except row 15. We sell it as extra legroom but in my opinion the worst row of seats on board.

Whip

Might have been a bit of leading edge ice.....couldn't see the leading edge, but all of the top surface.
And yes, I enjoyed myself immensely. Until I returned to -26! LOL Your backend folks are always upbeat and friendly. Some aren't, you know.
We're getting a little anal about de-icing, but better to do it when it's not needed, than not do it when it is.

[Canoehead]

Keep in mind that if the airplane is deiced by a contracted company, there is little incentive to be conservative with glycol. The more that goes through the nozzle the better the number$ are for the applicator (both as an individual and as a company). Minimal environmental considerations as the glycol is recovered (at the major airports), so it's as much about making money as cleaning the airplane. While the crew likely asked for "leading edges only", they probably got more than they really required or asked for.

As for being a little anal about it, any "discretion" that was once commonplace was basically taken away in March 1989. No captain with any sense will take any chances. It's just not worth the risk- personally or corporately.

[Dh8Classic]

We're getting a little anal about de-icing, but better to do it when it's not needed, than not do it when it is.

Anal about de-icing......do you take off with a bit of contamination sometimes???

[thatlowtimer]

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[Liquid Charlie]

Anal about de-icing......do you take off with a bit of contamination sometimes???

Every time I deice !!!!!

[Waldo Peppar]

Quote:
While the crew likely asked for "leading edges only", they probably got more than they really required or asked for.

If I remember correctly, there is no such thing a "leading edges only deicing?" If deicing fluid is applied to a wing,it must be the whole wing, and both wings evenly.

[linecrew]

Back when I used to de-ice, we only sprayed what the crews requested...but then again, we worked for, and the equipment was owned by, the airline. In other words, if they picked up ice on the approach and there was no contamination aft of the leading edge we didn't waste expensive de-icing fluid spraying parts that didn't need it for safe operation. Maybe liability wasn't as prevalent back then. Who knows.

[Doc]

Anal about de-icing......do you take off with a bit of contamination sometimes???

Every time I deice !!!!!

Good point. A wing covered with de-fluid is more "contaminated" than one with a little leading edge "glaze".

[Canoehead]

Quote:
While the crew likely asked for "leading edges only", they probably got more than they really required or asked for.

If I remember correctly, there is no such thing a "leading edges only deicing?" If deicing fluid is applied to a wing,it must be the whole wing, and both wings evenly.

I suppose it's possible that a company might not recognize a 'leading edges only' request. Type 1 fluid is different than types 2,3 & 4. There are no performance penalties with Type 1 fluid. I'm not convinced that if Type 1 fluid is applied to a wing it must be the whole wing. I do agree that it must be applied evenly ("symmetrically").

Given the likely scenario Doc described and whipline responded with, there is no need to douse the entire wing in Type 1 fluid, if all that was being removed was leading edge impact ice from the previous arrival.
(And re-reading Docs OP, it's possible that that's all they did).

[Donald]

If deicing fluid is applied to a wing,it must be the whole wing, and both wings evenly.

Ever heard of spot de-icing for fuel tank frost? Both wings are sprayed the same, but only in the area of the fuel tanks.

[whiteguy]

If deicing fluid is applied to a wing,it must be the whole wing, and both wings evenly.

Ever heard of spot de-icing for fuel tank frost? Both wings are sprayed the same, but only in the area of the fuel tanks.

When I was at AC we used to "spot" spray. By the time I left spot sprays were not allowed, the entire wing had to be sprayed. I was told at the time it was a TC requirement.

[fish4life]

I know this is going to start a massive debate but I think we are getting a little anal about de-icing the way the rules are. Like anything they had to make the rules because a few people pushed the limits. Lets be honest your flying a king air and just dropped off a load of passengers up north and on approach you picked up the thinnest strip of clear ice where your boots are still black and you don't notice it unless you really look. Throw on the fact it is snowing with some light fluffy flurries, are you going to de ice and load your wing up with de ice fluid that is now going to attract more contamination and real world performance penalty or are you going to be better off just to take off and go ? Legally you de ice every time but is it honestly the better or safer thing to do ? Probably not.


And to be clear I'm not talking about taking off with a 1/4 inch of ice or more kinda thing. In fact I'd like to see some manufacturers certify the aircraft for take off with light leading edge contamination that could be flight tested to prove your safe doing so I bet every northern company would be all over that mod.

[Doc]

I know this is going to start a massive debate but I think we are getting a little anal about de-icing the way the rules are. Like anything they had to make the rules because a few people pushed the limits. Lets be honest your flying a king air and just dropped off a load of passengers up north and on approach you picked up the thinnest strip of clear ice where your boots are still black and you don't notice it unless you really look. Throw on the fact it is snowing with some light fluffy flurries, are you going to de ice and load your wing up with de ice fluid that is now going to attract more contamination and real world performance penalty or are you going to be better off just to take off and go ? Legally you de ice every time but is it honestly the better or safer thing to do ? Probably not.


And to be clear I'm not talking about taking off with a 1/4 inch of ice or more kinda thing. In fact I'd like to see some manufacturers certify the aircraft for take off with light leading edge contamination that could be flight tested to prove your safe doing so I bet every northern company would be all over that mod.

I am 100% in agreement with your entire statement. Can you say "dumb down"? Knew ya could.
This will stir it up. I see no problem with 1/8 inch on the leading edge. You landed with it!
Flame away!

[DHC-1 Jockey]

This will stir it up. I see no problem with 1/8 inch on the leading edge.

The problem with this is one person's 1/8" is another person's 1/4". Unless we all start getting out rulers or micrometers, how do can we definitively say how much ice we have? In a world of lawyers and lawsuits, all it takes is one transport inspector sitting in the back to see you take off with a wing not adhering to the "clean wing concept" and then you have some explaining to do. So now it comes down to black and white. Absolutely and definitively no contamination, good to go. 1/32" or even the SUSPICION of something there, go deice.

I had one captain say it best when he said "I know it'll fly, but I really don't need the lawsuit if it doesn't. We're going for a spray."

[Doc]

This will stir it up. I see no problem with 1/8 inch on the leading edge.

The problem with this is one person's 1/8" is another person's 1/4". Unless we all start getting out rulers or micrometers, how do can we definitively say how much ice we have?

And THIS ladies and gentlemen, is why we have the "clean wing concept". I know when it will and will not fly. I have the stains to prove it! (Nothing is more terrifying than getting into the air in an airplane that really SHOULD have been de-iced!) You may NOT. Therefore.....de-ice.

[Doc]

Woman who used to do my laundry...."You did not de-ice, did you?"
Me....."How do you know?"
She...."Had to use very much bleach....your whites, no white, no more..."

[Doc]

Even with wing covers...

Covered the DC3 on night in Hearst. Freezing rain. Much freezing rain.
Pealed covers off (I mean pealed!) next morning. We could see patterns on the wings left by the frozen covers. Thought nothing of it.
Well, it bloody nearly killed us! Struggled around the circuit at well under 100 feet. Very gentle turns. Landed. Took the rest of the day off. One of the few times I've really had to "fly" my way to safety. Been a giant chicken ever since.

[parallel60]

Giant Chicken is the best way to be....you get to stay in the industry and gain the grey hair of experience.

[CID]

I knew a lady who flew occasionally for FedEx out of YWG. She took off with a thin layer of ice on a 208 and made a smoking hole in a neighbourhood in central Winnipeg shortly after take off.

And Doc, I figured you were old enough to remember the Air Ontario crash in Dryden that set the tone for the latest regulations regarding de-icing. So why are we even having this discussion? From a pure liability standpoint, pilots have not been 100% successful in determining what is OK when it comes to contamination. So the government took the decision away. It even empowered passengers to have the airplane de-iced on request.

How bad is that when a passenger sometimes knows better than a pilot?

And what's all this about the airplane being "contaminated" when it's sprayed? De-ice fluid on the airframe has a know and well documented affect on performance. So why are we even considering it an issue and whining about having it attached to the airplane?

Is it a pride thing Doc? Maybe you don't like being told when to de-ice?

[CpnCrunch]

From NTSB:

"Research results have shown that fine particles of frost or ice, the size of a grain of table salt and distributed as sparsely as one per square centimeter over an airplane wing's upper surface can destroy enough lift to prevent that airplane from taking off."

http://www.ntsb.gov/news/2004/041229.htm

Sounds crazy that such a small amount of ice can completely destroy your lift, but apparently it does.

I think the point is that the deicing fluid is a "fluid", so therefore it tends to conform to the shape of the wing and doesn't affect the laminar flow of the air moving over the wing.

[thatlowtimer]

I would love to see these tests, I have no idea what airplane they were using but it's B.S. Even just having a little bit of experience I can positively say that whole table salt mumbo jumbo is garbage. What's the percentages of loss of lift, something like 30% loss of lift and 40% increase of drag... Get real. Based on those numbers we should be able to increase our useful load by at least 30% in the summer.

Just get out a damn broom if you're worried about your frost and sweep for facks sake.

[turbo-prop]

It is apples and oranges. Turbo props with thicker wings fly away no problem. Jets with thin swept wings terrible idea to try and fly away without de icing. Like Doc said 1/8" on a turbo prop.