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Clean Wing Policy - How Clean?  
User currently offlinesmartt1982 From United Kingdom, joined Nov 2007, 225 posts, RR: 0
Posted (1 year 6 months 4 days 14 hours ago) and read 5953 times:

I know the term is referred to a “clean wing” policy in relation to icing etc. but how clean does it need to be?
On a recent departure we had been de-iced accordingly but when getting to the destination and doing a walk around I noticed on the fuselage all the residue from the dicing fluid, on the wings particularly I noticed what I would describe as a greasy residue from the deice fluid but combined with all the dirt that had been there previously.
Anyone had much experience of this sort of scenario?

28 replies: All unread, showing first 25:
 
User currently offlinetb727 From United States of America, joined Jun 2005, 1576 posts, RR: 9
Reply 1, posted (1 year 6 months 4 days 14 hours ago) and read 5934 times:

Was it clean of snow and ice? After deice did you look at the wing before you took off?


Too lazy to work, too scared to steal!
User currently offlineTristarsteve From Sweden, joined Nov 2005, 3982 posts, RR: 34
Reply 2, posted (1 year 6 months 4 days 14 hours ago) and read 5928 times:

Yes. When they tell you that deicing fluid flows off during the takeoff run, they were lying.
Type 11 and 1V fluids are very viscous and easily stay around all flight. Then they start dripping off the aircraft on arrival, and the crew report fuel leaks!
Had one this week dripping deice fluid off the rudder onto the APU exhaust creating clouds of smoke.


User currently offlinesmartt1982 From United Kingdom, joined Nov 2007, 225 posts, RR: 0
Reply 3, posted (1 year 6 months 4 days 13 hours ago) and read 5906 times:

Quoting tb727 (Reply 1):
Was it clean of snow and ice? After deice did you look at the wing before you took off?

Oh yeah, no issue there


User currently offlinetb727 From United States of America, joined Jun 2005, 1576 posts, RR: 9
Reply 4, posted (1 year 6 months 4 days 13 hours ago) and read 5868 times:

Quoting smartt1982 (Reply 3):
Oh yeah, no issue there

That's what they mean by clean wing, no snow or ice adhering. Sure some residual fluid will stick, that's what it does, but it's not going to effect your performance like the roughness and weight of snow and ice.



Too lazy to work, too scared to steal!
User currently offlinesmartt1982 From United Kingdom, joined Nov 2007, 225 posts, RR: 0
Reply 5, posted (1 year 6 months 4 days 11 hours ago) and read 5788 times:

Quoting tb727 (Reply 4):
but it's not going to effect your performance like the roughness and weight of snow and ice

cheers tb727, thats what I was wondering about, basically is there some sort of level/threshold were greasy dirt will become as bad as snow/ice accretion etc


User currently offlinetb727 From United States of America, joined Jun 2005, 1576 posts, RR: 9
Reply 6, posted (1 year 6 months 4 days 10 hours ago) and read 5737 times:

Quoting smartt1982 (Reply 5):
cheers tb727, thats what I was wondering about, basically is there some sort of level/threshold were greasy dirt will become as bad as snow/ice accretion etc

I don't know if it's just an illusion or not, but when I fly an airplane that has a fresh coat of nice glossy paint on it, I feel it flies better versus one that is dirty and gritty. When I flew smaller jets I would have maintenance wash them on overnights if it was filthy, not only did it look bad but it also probably has a minuscule amount of drag.

I'm sure at some point it could have a noticeable effect on performance but it would probably have to be a ridiculous amount of greasy dirt to do something.



Too lazy to work, too scared to steal!
User currently offlineSenchingo From Germany, joined Oct 2010, 111 posts, RR: 0
Reply 7, posted (1 year 6 months 4 days 8 hours ago) and read 5672 times:

Quoting Tristarsteve (Reply 2):
Yes. When they tell you that deicing fluid flows off during the takeoff run, they were lying.

It should flow off during T/O run actually. That's one of the reasons why during snow operation, usually the first 1/3 of the runway is reported a more poor braking action then the other 2/3. If you see the liquid close up or touch it, you'll realize that it's kind of an oily, very thick, viscous substance. If you drive on it (i did once in an airport car for runway check) you feel that the grip is reduced quite a bit.

Quoting smartt1982 (Thread starter):
I know the term is referred to a “clean wing” policy in relation to icing etc. but how clean does it need to be?

I think "clean wing" is a general term to say the wing should be as clean as possible, as any snow, dirt, ice etc on it will reduce lift (and also increase weight).

Quoting tb727 (Reply 6):
When I flew smaller jets I would have maintenance wash them on overnights if it was filthy, not only did it look bad but it also probably has a minuscule amount of drag

There have been quite some discussions about airlines and the cleanliness of their aircraft which i can't confirm, but from my personal opinion, i thought LH and NH's aircraft were extremely clean while AF, BA and IB to me seemed a bit "dirty".
BTW: Saw JL's cleaning machine last time i departed from NRT. Very neat indeed.
http://www.narita-airport.jp/en/fun/...lery/photo/vol_07/wall/w832_15.jpg


User currently offlinemhkansan From United States of America, joined Jan 2010, 672 posts, RR: 1
Reply 8, posted (1 year 6 months 4 days 4 hours ago) and read 5546 times:

Type IV anti-icing fluid, which is used only during precipitation, is the only fluid "designed' to run off during takeoff.

Type I fluid is like water, well... more like Dr. Pepper. Most/all of it will wash off during takeoff, but especially inside flap farings and landing gear areas as well as engine nacelles it sticks around.


User currently offlineHAWK21M From India, joined Jan 2001, 31667 posts, RR: 56
Reply 9, posted (1 year 6 months 4 days 1 hour ago) and read 5464 times:

Clean wing .....would mean Clean wing aerodynamically free of Ice.

Quoting mhkansan (Reply 8):
Type IV anti-icing fluid, which is used only during precipitation, is the only fluid "designed' to run off during takeoff.

Type I fluid is like water, well... more like Dr. Pepper. Most/all of it will wash off during takeoff, but especially inside flap farings and landing gear areas as well as engine nacelles it sticks aroun

How does the boundary layer effect contribute in such cases.



Think of the brighter side!
User currently offlineAlias1024 From United States of America, joined Oct 2004, 2748 posts, RR: 2
Reply 10, posted (1 year 6 months 3 days 6 hours ago) and read 5235 times:

Quoting Senchingo (Reply 7):
It should flow off during T/O run actually.

Most of it does, but some fluid always sticks to the wings. Just this week I was performing a walkaround on an aircraft's first flight of the day and could visibly see and could feel on the wings a slippery, slimy layer of deicing fluid from the aircraft's last flight the previous night. I could see and feel deicing fluid residue on the wings almost eight hours after it had been applied to the aircraft, with the aircraft having flown a 90 minute flight during that eight hour time span.



It is a mistake to think you can solve any major problems with just potatoes.
User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 11, posted (1 year 5 months 1 week 4 days 4 hours ago) and read 4286 times:

"but how clean does it need to be?"

Crystal.

If you accept anything less, then you have contamination. Many medium turboprops have been cleared to use Type IV fluid, turboprops with Vr speeds less than 100 KIAS. The FAA has issued bulletins cautioning about control difficulties at Vr if this type of fluid is issued. HELLO! Control difficulties at Vr?

No Thank You.

Type IV fluids were NEVER designed to be used on turboprops such as King Air's and Dash 8's. Pressure from operators turned the FAA into a "friend", allowing Type IV to be used. Now, the FAA realizes the folly of this exercise.

You young folks out there - BEWARE!


User currently offlinem1m2 From Canada, joined Dec 2011, 83 posts, RR: 0
Reply 12, posted (1 year 5 months 1 week 4 days 3 hours ago) and read 4277 times:

I know on a 25 min flight a lot of type IV fluid will stay on a Dash 8. When we put it into a hangar and it warms up, it rains down onto the floor creating a very slippery mess. It mostly comes off flight controls such as the leading edges of ailerons and elevators where it is out of the slip-stream during flight.

User currently offlinegr8circle From Canada, joined Dec 2005, 3097 posts, RR: 4
Reply 13, posted (1 year 5 months 1 week 3 days 17 hours ago) and read 4143 times:

Couple of years back I flew YYZ-AUH on an EY A346......it was snowing at YYZ when we took off, so there was de-icing done......it was an orange liquid that was sprayed on the plane......all throughout the flight I could see orange streaks on the trailing edge of the wing and they were still very much there even when we landed at AUH 14 hours later   

User currently offlineMaddogJT8D From United States of America, joined Oct 2009, 397 posts, RR: 1
Reply 14, posted (1 year 5 months 1 week 3 days 15 hours ago) and read 4109 times:

Years and years ago, probably back around February 2000, my family and I flew on TWA36, a 767-200 (was equipment swapped from a 757) on the first flight out JFK-SJU. We had some snow fall over night which continued to fall into the morning and required us to deice. Fast forward to our arrival on our cruise ship at SJU when we received our checked luggage - all covered on orange deicing fluid! I always wondered how the bags could possibly have gotten covered with deicing fluid if they were already loaded on the aircraft, which led me to believe that they must have done some bag loading after we were deiced, or somehow the cans got covered from the ramp and it seeped inside onto the bags.

I did notice that much of the orange fluid stayed on the rear part of the wings throughout the flight and wasn't even fully gone after full flap extension during and after landing.


User currently offlineboeingfixer From Canada, joined Jul 2005, 529 posts, RR: 0
Reply 15, posted (1 year 5 months 1 week 3 days 7 hours ago) and read 4009 times:

Quoting Tristarsteve (Reply 2):
When they tell you that deicing fluid flows off during the takeoff run, they were lying.
Type 11 and 1V fluids are very viscous and easily stay around all flight.

Actually when Type IV anti-icing fluid is properly applied the majority of it shears off the wing carrying any post-spray contaminants with it during takeoff before rotation. I have witnessed this personally on several occasions while departing out of YYC. What stays on the wings is mostly the de-ice fluid under the Type IV and whatever little Type IV is left after takeoff. This is what makes a mess of the ramp, vehicles, coveralls, hair etc. after the aircraft lands and rains de-ice fluid all over the place.

Cheers,

John



Cheers, John YYC
User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 16, posted (1 year 5 months 1 hour ago) and read 3438 times:

@boeing fixer

Any contamination remaining at liftoff is just that - a contaminant, affecting the lift coefficient of the wing. Whether that contaminant is snow, frost or Type IV fluid, i.e. the subject of the FAA Bulletin.


User currently offlineboeingfixer From Canada, joined Jul 2005, 529 posts, RR: 0
Reply 17, posted (1 year 4 months 4 weeks 23 hours ago) and read 3263 times:

Quoting Yikes! (Reply 16):
@boeing fixer

Any contamination remaining at liftoff is just that - a contaminant, affecting the lift coefficient of the wing. Whether that contaminant is snow, frost or Type IV fluid, i.e. the subject of the FAA Bulletin.

Are you paraphrasing what I said in my post?

Quoting boeingfixer (Reply 15):
Actually when Type IV anti-icing fluid is properly applied the majority of it shears off the wing carrying any post-spray contaminants with it during takeoff before rotation.

Cheers,

John



Cheers, John YYC
User currently offlineFlyFree27 From United States of America, joined Feb 2013, 20 posts, RR: 0
Reply 18, posted (1 year 4 months 4 weeks 13 hours ago) and read 3188 times:

This is not a term taken lightly, however it is taken out of context. The term has nothing to do with cleanliness from dirt and grease. Just means clean from ice,snow, and even frost sometimes. Deicing fluid is generally heated and then pressure sprayed, the heat helps it to be applied and helps with melting the ice. Once it sits on aircraft skin, which typically is outside air temp, it begins to thicken up. Best comparison I can come up with is molasses but not as sticky and stringy. This time of year planes are caked in it, almost any part of the plane you touch will feel a little sticky and textured.

User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 19, posted (1 year 4 months 4 weeks 5 hours ago) and read 3105 times:

Quoting FlyFree27 (Reply 18):
Quoting FlyFree27 (Reply 18):
This is not a term taken lightly, however it is taken out of context. The term has nothing to do with cleanliness from dirt and grease. Just means clean from ice,snow, and even frost sometimes. Deicing fluid is generally heated and then pressure sprayed, the heat helps it to be applied and helps with melting the ice. Once it sits on aircraft skin, which typically is outside air temp, it begins to thicken up. Best comparison I can come up with is molasses but not as sticky and stringy. This time of year planes are caked in it, almost any part of the plane you touch will feel a little sticky and textured.

FlyFree27 - you have just illustrated you are part of the problem. You may have gotten away with what you say 100 times. Normalcy of deviance is the expression. Look it up.

The instant you accept any contamination is the instant you become a test pilot. Let your survivors explain that to your estate, God forbid you should become one of the many who have ignored this tenet.


User currently offlineboeingfixer From Canada, joined Jul 2005, 529 posts, RR: 0
Reply 20, posted (1 year 4 months 3 weeks 5 days 17 hours ago) and read 2975 times:

Quoting Yikes! (Reply 19):
FlyFree27 - you have just illustrated you are part of the problem. You may have gotten away with what you say 100 times. Normalcy of deviance is the expression. Look it up.

The instant you accept any contamination is the instant you become a test pilot. Let your survivors explain that to your estate, God forbid you should become one of the many who have ignored this tenet.

That is a very ignorant reply. Both in content and lack of knowledge in the subject.

What FlyFree27 was saying, not that I should have to paraphrase as it's quite clear, is that de-ice fluid itself is not a contaminant.

I am an AME working line/hangar maintenance in YYC for the past 13 years on B727/B757 and have seen and approved my fair share of aircraft de/anti-icing. 'Yikes!', please read the following closely and if you don't understand anything, ask a question instead of replying with insulting gibberish.

If you have ever been around an aircraft that has been de-iced with 50/50 Type I fluid/hot water you should know that after flying with such fluid on the wings, fuse etc. there is still a thin, slightly sticky layer left on the surface. In no way is this known as a contaminant. When an aircraft is combination de/anti-iced with Type I and IV fluids things change slightly. Type IV fluid is an Anti-Ice fluid only. It is to be applied after de-icing with Type I fluid. The properties of Type IV fluid are such that at speeds of around 100 knots, the viscosity breaks down and the fluid shears off the wing exposing the underlying Type I fluid. When the Type IV shears off the wing, it carries away any accumulated contamination after it was applied. This contamination is allowed and is accounted for in Hold-Over tables which takes into account the type of active precipitation and the OAT. BTW, not all of the Type IV fluid is carried away by the airflow due to boundary layer effect and traces of the green fluid will be seen on the aircraft upon landing, which is not contamination.

I could go on with more details but I don't think it will add any to what has already been posted.

Cheers,

John



Cheers, John YYC
User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 21, posted (1 year 4 months 3 weeks 2 days 14 hours ago) and read 2786 times:

To all of the above proponents of Type IV who have missed the point. With respect all aircraft with rotation speeds >100 knots, that is not the subject of my Caution. It is to types like Dash 8's, King Air's and other low-rotation speed turboprops.

The contaminant does NOT flow off. It stays. Not only does it affect the lift co-efficient, it is added WEIGHT.

It it doesn't flow off as it does on higher speed aircraft (I am a retired B767 driver, now flying medium turboprops), then it IS a contaminant, and it IS dangerous.


User currently offlinemayor From United States of America, joined Mar 2008, 10351 posts, RR: 14
Reply 22, posted (1 year 4 months 3 weeks 2 days 10 hours ago) and read 2735 times:

Quoting Yikes! (Reply 21):
To all of the above proponents of Type IV who have missed the point. With respect all aircraft with rotation speeds >100 knots, that is not the subject of my Caution. It is to types like Dash 8's, King Air's and other low-rotation speed turboprops.

Then you probably should have made that clearer. In some of your replies, you slammed those that were referring to a/c OTHER than turboprops, etc.



"A committee is a group of the unprepared, appointed by the unwilling, to do the unnecessary"----Fred Allen
User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 23, posted (1 year 4 months 3 weeks 2 days 3 hours ago) and read 2657 times:

Mayor: My initial post was CRYSTAL CLEAR referring to turboprops with VR less than 100 KIAS. Please re-read Reply #11 above.

User currently offlinemayor From United States of America, joined Mar 2008, 10351 posts, RR: 14
Reply 24, posted (1 year 4 months 3 weeks 2 days 1 hour ago) and read 2642 times:

Quoting Yikes! (Reply 23):
Mayor: My initial post was CRYSTAL CLEAR referring to turboprops with VR less than 100 KIAS. Please re-read Reply #11 above.

No, it was more like an addition to a statement implying that it was unsafe for ALL a/c and you threw in turboprops in as an example. Everyone else (except you) was referring to everything BUT turboprops.



"A committee is a group of the unprepared, appointed by the unwilling, to do the unnecessary"----Fred Allen
User currently offlinecrj900lr From United States of America, joined Mar 2011, 317 posts, RR: 0
Reply 25, posted (1 year 4 months 3 weeks 1 day 6 hours ago) and read 2548 times:

Quoting Yikes! (Reply 21):
It is to types like Dash 8's

I've deiced 100's of Dash-8's im my many years when I was on the ramp and not once did we ever have an issue with type IV fluid putting the aircraft in a dangerous position. You don't need alot of type IV to get the job done, the type 1 is what is used to initially remove any snow/frost/ice, thats where you are going to use alot of fluid. on a Dash-8 you should maybe use 8-10 gallons of type IV per side on the final application, and you must make sure the spring tabs flutter.


User currently offlineYikes! From Canada, joined Oct 2001, 284 posts, RR: 1
Reply 26, posted (1 year 4 months 2 weeks 6 days 3 hours ago) and read 2414 times:

Have any of you even read the FAA directive?

http://www.faa.gov/other_visit/aviat...all_safos/media/2010/SAFO10001.pdf

Mayor, you need some residual reading training.


User currently offlinemayor From United States of America, joined Mar 2008, 10351 posts, RR: 14
Reply 27, posted (1 year 4 months 2 weeks 5 days 16 hours ago) and read 2375 times:

Quoting Yikes! (Reply 26):
Mayor, you need some residual reading training.

You need to read these threads more often. I apologized for misinterpreting what you said and I think it was a communications problem. My apology was removed because of your post, which was also removed.

Quoting Yikes! (Reply 26):
Mayor, you need some residual reading training.

Makes no difference to me because I don't have to get in that damn bucket, anymore.....I'm retired.



"A committee is a group of the unprepared, appointed by the unwilling, to do the unnecessary"----Fred Allen
User currently offlineboeingfixer From Canada, joined Jul 2005, 529 posts, RR: 0
Reply 28, posted (1 year 4 months 2 weeks 4 days 5 hours ago) and read 2277 times:

Quoting Yikes! (Reply 21):
To all of the above proponents of Type IV who have missed the point.

Actually you had replied to my post with no consideration as to the type of aircraft I work on or was posting about. Also you did not pick up on the fact I was not replying to your initial post. A quick look at my Profile would have informed you that I was not referring to turboprop ops. It would appear as if YOU have missed the point.

Quoting mayor (Reply 22):
My initial post was CRYSTAL CLEAR referring to turboprops with VR less than 100 KIAS.

I will give you this. Unfortunately your replies stayed in that vein and did not allow any other replies for types other than turboprops.

Quoting Yikes! (Reply 26):
Have any of you even read the FAA directive?

http://www.faa.gov/other_visit/aviat...all_safos/media/2010/SAFO10001.pdf

Mayor, you need some residual reading training.

Thanks for the link to the SAFO. I would like to point out that it is NOT a directive. It is a Safety Alert for Operators which gives Recommended Action to the operators based on reports and not scientific data. Basically the difference between a Service Bulletin to an Airworthiness Directive. Recommended is the key word here and it appears you have taken it as a directive.

It appears as though you may need some remedial (not residual) reading training.

Regards,

John



Cheers, John YYC
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