757 De-ice

Lando

Pre-takeoff checklist
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Lando
I’m currently sitting in the back of a Delta 757 in Fargo, ND and we were just told that the de-ice fluid they have isn’t safe to use until the temperature rises 2 degrees...so apparently we’re stuck on the ground for now. The ASOS is reporting -23C (which is cold, but not bad at all by ND winter standards). There are three RJ’s right off our wing currrntly being de-iced and other traffic has been departing as well. What gives?
 
I’m currently sitting in the back of a Delta 757 in Fargo, ND and we were just told that the de-ice fluid they have isn’t safe to use until the temperature rises 2 degrees...so apparently we’re stuck on the ground for now. The ASOS is reporting -23C (which is cold, but not bad at all by ND winter standards). There are three RJ’s right off our wing currrntly being de-iced and other traffic has been departing as well. What gives?

Are those other aircraft the same company as yours?
 
Just a swag, but may not only be company related, but equipment related as well.
 
Maybe the de-ice fluid in the trucks needed to warm up more?? Not likely the air temp will warm up this morning and they just said they were waiting for the temp to rise another 1-2 degrees. I can’t get out of this cold weather fast enough!
 
Depends on the stength of the mixture. The de-ice fluid is diluted, and they have to test it for freezing point. Once you get this cold, it's easy to drop below the safe use temperature.
 
It's nippy today. About to go outside and see if my car starts after being cold-soaked at -15F for 12hrs.

757s dont come around all that often. The deice truck used for the larger birds may be different from the one used on the RJs.
 
Got stuck in New Bern, NC along the coast one morning due to freak unforcasted freezing rain last Spring. The airport only had unheated Type 1 from an ancient Cold War era truck. We had to time the deice and departure based on breaks in the freezing rain.
 
It's nippy today. About to go outside and see if my car starts after being cold-soaked at -15F

757s dont come around all that often. The deice truck used for the larger birds may be different from the one used on the RJs.

No difference in fluid between a 757 and an RJ. Could be a difference in the brand and mixture ratio used between 2 different airlines though.
 
I’m currently sitting in the back of a Delta 757 in Fargo, ND and we were just told that the de-ice fluid they have isn’t safe to use until the temperature rises 2 degrees...so apparently we’re stuck on the ground for now. The ASOS is reporting -23C (which is cold, but not bad at all by ND winter standards). There are three RJ’s right off our wing currrntly being de-iced and other traffic has been departing as well. What gives?

Deice only stays on the plane for so long, and are closely tied to temp. A larger plane will take longer to cover and as a result may not have sufficient time to climb before the first area covered times out. You also have to look at the climb rates of the planes; that 757 depending on loading may need more time to get to a safe altitude compared to the RJs.

Tim
 
Idiots probably goofed and filled the truck with chemtrail fluid. Happens alla time.
I know, right? Remember the week in EWR in 2008?

[Satire]
Airline pilot here, so I'll preface this with tremendous arrogance and the fact that I'm pretty much right all the time. Just ask me.
[/Satire]

I can see that if they squirted a scope busting RJ or two first, I bet they needed to fill the truck for a 75'. Especially if they don't get them often. Then they need to heat that goo up to 180 before squirting the big one.

There are different deice-anti ice rules for every airline. DAL might have some rule where they can only use type 1 at certain air temps due to cooling of the fluid from tip to surface. Which is also totally dependent on the 100 different types of types 1 and 4, dilution ratios, training of the deice crew, truck equipment, etc...

[Satire]
So, there's no telling what is going on. I'll expect you to debrief the pilots. Let them know you know an airline pilot or two on a forum, and they expect a report.
[/Satire]

Sent from my SAMSUNG-SM-G891A using Tapatalk
 
Deice only stays on the plane for so long, and are closely tied to temp. A larger plane will take longer to cover and as a result may not have sufficient time to climb before the first area covered times out. You also have to look at the climb rates of the planes; that 757 depending on loading may need more time to get to a safe altitude compared to the RJs.

Tim

Deicing hold over times have nothing to do with climb rates. Deice fluid is to protect an aircraft on the ground. You have to start the takeoff roll before this expires.
Once you’re in the air the aircraft’s ice protection systems take care of you.

A larger plane might take a few minutes longer but unless you’re sitting there in really heavy snow it’s not going to matter and I don’t think it was snowing in FAR this morning, just really cold and probably a frosty airplane.
 
Fargo Delta Global Services ( the guys who operate the deice truck for Delta) ran out of fluid entirely a few years ago. Was a huge blow to the airport as all the news outlets blamed the airport for an issue that was Delta's. So it wouldn't entirely surprise me if they diluted it too much (in attempt to stretch what they had) and its now below use temp.
 
Deicing hold over times have nothing to do with climb rates. Deice fluid is to protect an aircraft on the ground. You have to start the takeoff roll before this expires.
Once you’re in the air the aircraft’s ice protection systems take care of you.

A larger plane might take a few minutes longer but unless you’re sitting there in really heavy snow it’s not going to matter and I don’t think it was snowing in FAR this morning, just really cold and probably a frosty airplane.

I do not fly the big iron :D
But that was how it was explained to me; even though airlines have deice on the plane (hot bleed air being the most common), pretty much all the ops specs for airlines need some level of marginal protection for the initial climb segment. Basically, the first few minutes.

Tim
 
I do not fly the big iron :D
But that was how it was explained to me; even though airlines have deice on the plane (hot bleed air being the most common), pretty much all the ops specs for airlines need some level of marginal protection for the initial climb segment. Basically, the first few minutes.

Tim
Doesn’t really have anything to do with the climb. We just need to be off the ground before the holdover time expires. If not, we have to get sprayed again. Each deice fluid, depending on mixture, OAT, precipitation intensity/type, etc has a different holdover time.
 
I do not fly the big iron :D
But that was how it was explained to me; even though airlines have deice on the plane (hot bleed air being the most common), pretty much all the ops specs for airlines need some level of marginal protection for the initial climb segment. Basically, the first few minutes.

Tim

The deice fluid (Type IV), is designed to shear off at around 90kts. The only thing exposed to ice accumulation is the leading edges once you’re moving and that is protected like you said.
 
I’m currently sitting in the back of a Delta 757 in Fargo, ND and we were just told that the de-ice fluid they have isn’t safe to use until the temperature rises 2 degrees...so apparently we’re stuck on the ground for now. The ASOS is reporting -23C (which is cold, but not bad at all by ND winter standards). There are three RJ’s right off our wing currrntly being de-iced and other traffic has been departing as well. What gives?

Just curious how long it took to get out of there
 
No difference in fluid between a 757 and an RJ. Could be a difference in the brand and mixture ratio used between 2 different airlines though.

I said the truck may be different, not the fluid. The only 'heavies' that get into Fargo are the occasional freighters , the UPS parcel collector and when Delta has a problem at MSP. At times, the airlines will use contracted equipment from the Fargo Jet Center to service aircraft that are outside of their usual schedule. Some of the deice trucks used are the 'open bucket' style and there may well be restrictions on the temperature they can be used at. Bottom line is that one airline (Skywest) may be able to go while another can't. I have experienced that some years back with a fueling misadventure.

Oh, and it wasn't all that cold this morning. Barely -5, not the -18 the TV was talking about. I swung by the airport at 8:20 and somehow the Delta 757 must have gotten out.
 
I said the truck may be different, not the fluid. The only 'heavies' that get into Fargo are the occasional freighters , the UPS parcel collector and when Delta has a problem at MSP. At times, the airlines will use contracted equipment from the Fargo Jet Center to service aircraft that are outside of their usual schedule. Some of the deice trucks used are the 'open bucket' style and there may well be restrictions on the temperature they can be used at. Bottom line is that one airline (Skywest) may be able to go while another can't. I have experienced that some years back with a fueling misadventure.

Oh, and it wasn't all that cold this morning. Barely -5, not the -18 the TV was talking about. I swung by the airport at 8:20 and somehow the Delta 757 must have gotten out.

Gotcha. Took that as comparing the fluid, not the limitations of the trucks.
 
Oh, and it wasn't all that cold this morning. Barely -5, not the -18 the TV was talking about. I swung by the airport at 8:20 and somehow the Delta 757 must have gotten out.

I occasionally watch the weather portion of local network affiliates' news broadcasts. Lately they have substituted the low temperature reported and forecast with the calculated temperature including the wind chill factor.

Unless you're paying attention, it's easy to miss. The weather guy says "It feels like X right now, and will feel like Y later tonight". They don't bother saying it's not the actual temperature.

This misinformation is part of the local weathermens' effort to be the story and alarm the audience. In another example, when I lived in Houston, it seemed like every tropical storm that entered the Gulf was immediately forecast to flatten Galveston, then roll up I-45 and devastate Houston.

Besides wearing a bow tie, this is the only way TV weathermen can gain recognition.
 
I occasionally watch the weather portion of local network affiliates' news broadcasts. Lately they have substituted the low temperature reported and forecast with the calculated temperature including the wind chill factor.

Oh the windchills this morning were supposed to be -30. Doom and gloom, insta-death to anyone who doesn't have a survival kit....
The reality was -5F and light and variable wind.
 
Get the CEO to talk to the plane, the hot air should solve all the problems.

Our mayor lately has taken great interest in the airport. I'll suggest to the airport director to put the mayor on the de-ice crew. Just hold a copy of the airport budget in front of him and he can produce enough hot air to deice a heavy.
 
I occasionally watch the weather portion of local network affiliates' news broadcasts. Lately they have substituted the low temperature reported and forecast with the calculated temperature including the wind chill factor.

Unless you're paying attention, it's easy to miss. The weather guy says "It feels like X right now, and will feel like Y later tonight". They don't bother saying it's not the actual temperature.

This misinformation is part of the local weathermens' effort to be the story and alarm the audience. In another example, when I lived in Houston, it seemed like every tropical storm that entered the Gulf was immediately forecast to flatten Galveston, then roll up I-45 and devastate Houston.

Besides wearing a bow tie, this is the only way TV weathermen can gain recognition.

I get where you are going but to 90% of people they couldn't give two ****s what the actual temp is because all that will ever matter/they need to care about is what it feels like. "It's negative five today." Ignoring the 20 mph wind making it feel much colder than that.
 
I’m currently sitting in the back of a Delta 757 in Fargo, ND and we were just told that the de-ice fluid they have isn’t safe to use until the temperature rises 2 degrees...so apparently we’re stuck on the ground for now. The ASOS is reporting -23C (which is cold, but not bad at all by ND winter standards). There are three RJ’s right off our wing currrntly being de-iced and other traffic has been departing as well. What gives?
Could be several reasons but most likely it was due to a deice fluid LOUT limitation or Lowest Operational Use Temperature and it can vary by aircraft type.
 
Today's deicing adventure: we are in a minor blizzard. CRJ got deiced with type I and covered with type IV. We are at the hold short line and the 12 year old FO gets sent back to check. Of course, the film 'failed' in the two minutes it took to taxi to the runway. Now we are back on the pad waiting for the lone deicing truck to warm up a fresh boiler full of fluid. By the time he'll deice us we will be either out of fuel or MSP will be on ground-stop due to the blizzard.

#lifeinthefrozentundra
 
And we are out of fuel....
Back to the gate
Oh wait, no gate available......
 
Deicing/anti-icing is a two-step process.

Heated Type I fluid is used remove snow, ice, and frost that is already on the airplane. Type I can be diluted, as it is very expensive, but diluting it increases its freezing temperature so undiluted Type I can be used in colder temperatures than when it is diluted. A minimum temperature is established based on the level of dilution. i.e. 50/50, 75/25, etc.

While heated Type I fluid is very good at cleaning off contamination, it does not provide much protection against the accumulation of additional contamination if the snow, sleet, frost, etc. is still falling. In fact, if the icing conditions are continuing, it is likely impossible to deice and takeoff before the Type I has lost its ability to protect the airplane.

If the icing conditions are ongoing, the heated Type I application is followed by Type IV fluid, applied cold and undiluted, as an anti-icing step. The Type IV goes on thick, almost like a gel, which sits on the aircraft and prevents additional accumulation of contaminants on the airplane. During the takeoff roll, the coating of Type IV sheers off the airplane taking the built up snow/ice with it leaving the airplane clean by liftoff speed.

In conditions where Type I can protect the airplane for ten or fifteen minutes, Type IV can protect it for two to three hours. We deiced with Type I and IV last night in Chicago. Our Type I holdover time was 11 minutes. Our Type IV holdover time was 154 minutes. Timing starts at the BEGINNING of the last anti-icing application process so, with Type I alone, there's no way we would have been able to takeoff.

The purpose of these fluid applications is to provide a clean airplane at liftoff. They offer no protection once airborne where the aircraft's own anti-icing systems take over.
 
Well, another company crew showed them 'how it's done ' and we got out despite the wind and blowing snow.
 
What Larry in TN said is correct. The fluid is designed to shear off at about 90 knots....this can lead to another potential problem. After a series of takeoffs, all of which reach a similar area of the runway and the fluid shears off...and the unlucky guy has to reject their takeoff in that now slick area. Fun fun fun.

Trivia about anti-ice on the 757. NONE, ZERO, NADA of the tail is heated, de-iced or anti-iced. Why? Because it’s a Boeing...and the wing design and that magic math that aerodynamic engineers use.
 
The fluid is designed to shear off at about 90 knots....this can lead to another potential problem.

Also why you don't normally see Type IV used on prop planes, including turboprops. The fluid is still on the plane at rotation.
 
The deice fluid (Type IV), is designed to shear off at around 90kts. The only thing exposed to ice accumulation is the leading edges once you’re moving and that is protected like you said.
Type IV is anti-ice fluid, but the rest of your post is correct.
Also why you don't normally see Type IV used on prop planes, including turboprops. The fluid is still on the plane at rotation.
I've anti-iced many many Saabs and a couple ATRs. They most certainly get Type IV.
 
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