With Chicago expected to reach temperatures below -20 degrees F later this week, is there potential for flight disruptions?

It is my understanding that airplanes perform better in colder weather, however, can delays come from issues with operations and the crews on the tarmac?

Concern is staff across the board and making sure folks aren’t out more than necessary.

Fueling is another, ORD has more than enough fuel on hand, but the delivery (Tankers, Hydrant trucks, carts) is the major concern about freezing up.

A few cancellations already by the foreign flags for Tuesday, not sure yet on the domestics.

United has said they are running a reduced operation at ORD this week. As mentioned above probably more so for the safety of employees including ramp persons

jcwr56 wrote:

Concern is staff across the board and making sure folks aren’t out more than necessary.

Fueling is another, ORD has more than enough fuel on hand, but the delivery (Tankers, Hydrant trucks, carts) is the major concern about freezing up.

A few cancellations already by the foreign flags for Tuesday, not sure yet on the domestics.

Thanks for the response! Bad week overall, especially for UA and AA, as I know there were a ton of cancellations into ORD today as well

Aircraft are cold-soaked during testing at much lower temps than that. As others have said, it is ground staff and vehicles that may be impacted.

So I am flying back home tomorrow to ORD and everyone is anticipating delays because of the extreme cold. (High of 6 and Low of -21). I can understand the horrible conditions are tough for the ramp workers and might slow turn around time some. But would that have a noticeable affect on operations? What other elements are affected. What I can expect for delays and cancellations tomorrow?

Note: not talking about the snow, that finished today.

-55 with the wind chill factored in. Not fun.

-40C is a standard limitation on aircraft

However, as others pointed out, the human limitation is much more of an issue

Years ago I remember United worked to develope some sort of face mask that offered protection on the ramp..... anyone remember

MDW WN already canceled hundreds of flights this week because of the extreme weather.

Flyguy

I think the OP is speaking in Fahrenheit, as OP is talking about the weather in ORD.

A high of 6F and a low of -21F would be:

-14C to -30C.

I don't think that those are perfectly normal winter temperatures in many parts of the rest of the world. In Alaska, Canada, Siberia, Scandinavia, perhaps. But for ORD, this is colder than normal. And Chicago is a cold city as it is.

The aircraft themselves should be fine. But I would think the issue would be all the ground equipment freezing up and not starting. Plus with a windchill estimated to be down around -50F (-46C), employees being subject to frostbite issues will probably be the number one concern.

Those temps are common for ORD this time of year.... it's the wind chill that gets bad

What about DTW? Weather isn't going to be much better there...

YoungDon wrote:

What about DTW? Weather isn't going to be much better there...

I think as far as hubs go MSP is going to take the cake. -29*F on Wednesday. Wind chills metrics surpassing -50*F

BobbyPSP wrote:

Those temps are common for ORD this time of year.... it's the wind chill that gets bad

The forecast temps are 40 degrees below normal and will be approaching all time record lows and low highs - i.e. not "common"

United787 wrote:

But would that have a noticeable affect on operations?

Smokey engines start at least on the RB211 and PW4460.

United787 wrote:

So I am flying back home tomorrow to ORD and everyone is anticipating delays because of the extreme cold. (High of 6 and Low of -21). I can understand the horrible conditions are tough for the ramp workers and might slow turn around time some. But would that have a noticeable affect on operations? What other elements are affected. What I can expect for delays and cancellations tomorrow?

Note: not talking about the snow, that finished today.

Do you read the fourm before posting? I literally posted the same topic about 10 minutes before you. Titled 'Will there be Disruptions due to ORD Temperature'...

Happened that aircrafts did not operate because temperature dropped below what the manufacturer has set documents to and so couldn't have reference to what parameters to use.

GFK, FAR, BJI, BRD, INL will all be pushing -40 F Wednesday night. I feel terrible for pilots during the outside airplane inspection.

Reminds me of the polar vortex of early 2014, during which I had the misfortune of passing through ORD. All flights except for a select few operated by larger aircraft were cancelled, meaning I was stuck in Chicago for 2 nights. Airline employees were telling me that fuel freezing was one of the reasons why flights were being cancelled, and IIRC the temperatures then were about the same as what's forecast in a few days.

Also,

OneX123 wrote:

It is my understanding that airplanes perform better in colder weather

This is technically true- colder air means better engine performance, more lift, etc due to how much denser the air is. However, cold air often comes coupled with low visibility, high winds, heavy precipitation, and bad taxiway/runway conditions. I'm not sure if there's a lot more snow forecast or if the rest of the week is just going to be cold, but I'd expect pretty bad operational delays.

Personal anecdote about aircraft performance in cold weather. On the day of my checkride it was a completely clear, beautiful day, and the temperature was about -5F IIRC. No matter how hard I tried I couldn't get my 172 to stall. Thankfully, the examiner was a great guy who didn't dock me points for it!

N415XJ wrote:

Reminds me of the polar vortex of early 2014, during which I had the misfortune of passing through ORD. All flights except for a select few operated by larger aircraft were cancelled, meaning I was stuck in Chicago for 2 nights. Airline employees were telling me that fuel freezing was one of the reasons why flights were being cancelled, and IIRC the temperatures then were about the same as what's forecast in a few days.

Also,

OneX123 wrote:

It is my understanding that airplanes perform better in colder weather

This is technically true- colder air means better engine performance, more lift, etc due to how much denser the air is. However, cold air often comes coupled with low visibility, high winds, heavy precipitation, and bad taxiway/runway conditions. I'm not sure if there's a lot more snow forecast or if the rest of the week is just going to be cold, but I'd expect pretty bad operational delays.

Yes fuel did freeze at ORD in 2014: https://www.scientificamerican.com/arti ... states-di/

The lows will be ~5-10 degrees colder this time around too...so it could happen again.

OneX123 wrote:

Do you read the fourm before posting? I literally posted the same topic about 10 minutes before you. Titled 'Will there be Disruptions due to ORD Temperature'...

You could try typing a little nicer. I do read the forum before posting. I took well over ten minutes typing my posts because I became distracted with something else half way through. I think humanity will survive this...

Everything will move much slower. Tasks will take 2-3 times longer than normal. Only essential tasks should be attempted.

The temperature won't impact operations. Temperature affects altimetry and other particulars that concern the crew, but which won't be visible to you.

The only issues with low temperature are weather (ground and inflight icing, runway condition, fog, etc) and in prolonged operation at high altitude, fuel temperature. Occasionally there are issues with ground equipment such as jetways or tugs, but largely those are non-issues that you won't see.

Remember that it's typically about -54 at altitude when in cruise; aircraft normally operate in cold temperatures a great deal of time, even in the summer; the cold itself isn't really that big of a challenge. Unless you have weather present that creates icing conditions or fog, it probably won't impact you at all.

BobbyPSP wrote:

Those temps are common for ORD this time of year.... it's the wind chill that gets bad

Those temps ARE NOT common for ORD at any time of year. The high Wednesday is forecast to be -12F which would be the lowest high temperature in the history of the city.

AND temps are affecting flight ops at MDW. All Wednesday and Thursday flights from MDW to DAL have been cancelled/ I suspect it's more just MDW to DAL.

Oh, and my DAL / MDW flight on Wed. was cancelled earlier today -- as were all the others.

Here are some issues that I have had in very cold weather:
Starting up the airplane, some of the avionics do not power up
The APU is frozen shut
APU won't start
Aircraft is covered in frost requiring deicing (small delay)
Congealed fuel (we have minimum fuel temperatures, so if the fuel is too cold, we can't go and have to wait for it to warm up)
Thrust reversers deploy too slowly (below certain temperatures, we have to run a thrust reverser deployment test to see how long it takes for them to deploy. If it takes too long, flight will be delayed until it warms up and the deployment time meets the limitations)
Inground fueling equipment frozen over, requiring the use of fuel trucks which may be limited in number

There are many other possible things that could occur. Go put your smartphone in the freezer for 10 minutes and pull it out and see how it works. Now imagine that you left it in the freezer overnight and pull it out and imagine how it would work. That's what happens to many of the electronic and mechanical components of the airplane and also ground equipment.

Yes it effects operations as it limits the time the ramp personnel is allowed outside in extreme cold.

My first airline job was the original Midway Airlines at LGA. They sent us to MDW in February for ramp training, it was brutally cold and extreme wind, they would only allow people outside for 10-15 minutes and had extra heaters in the break rooms and free hot beverages.

Also in extreme cold diesel fuel coagulates and ground equipment won’t work.

Lav and water trucks freeze.

When I was in CLT in maintenance when it got cold all lav and water trucks were parked in the hangar, and the ramp tried to park as much equipment inside as possible.

GSE would have to go around before the first bank to make sure the pushback tugs would start and lots of ground equipment was left running overnight.

Boof02671 wrote:

Yes it effects operations as it limits the time the ramp personnel is allowed outside in extreme cold.

My first airline job was the oringinal Midway Airlines at LGA. They sent us to MDW in February for ramp training, it was brutally cold and extreme wind, they would only allow people outside for 10-15 minutes and had extra heaters in the break rooms and free hot beverages.

Yup, exposed flesh (face, ears, hands) subject to frostbite in 5-10 minutes. I've been frostbitten while skiing maybe 10 times.

If the aircraft is not kept on ground power and air the onboard battery can freeze and the aircraft will not be able to start its APU until external power can be supplied.

There are all manner of things that temperatures can affect that you wouldn't necessarily think about until you've been in a cold weather station for awhile. And it starts at a much warmer temperature than is anticipated for several days this week.

Put simply, equipment will be unreliable, staff will be miserable, and tasks that would be easy if the temperature were above ~25F will be very difficult to nearly impossible.

BBDFlyer wrote:

Go put your smartphone in the freezer for 10 minutes and pull it out and see how it works. Now imagine that you left it in the freezer overnight and pull it out and imagine how it would work. That's what happens to many of the electronic and mechanical components of the airplane and also ground equipment.

It really isn't.

An aircraft is not a smart phone.

The sky isn't falling, and the world won't come to an end with slightly lower temperatures. Regarding APU's freezing solid...these APU's are cold soaked well below expected temperatures at ORD in the next few days; cold soaked this way with every landing. And yet they're started upon landing.

Ground power can be preheated. Huffers are available. Dipstick heating elements, too, and equipment will be run and warmed up before use. Antifreeze can be applied where needed. Deice equipment is available. These temperatures aren't unusual at places like Siberia and Fairbanks, Alaska, or much of Canada, and yet operations continue. Every day.

I wouldn't think there would be any major impact if everyone knows what they're doing.

I know QK keeps their APU running under -25 or -30 Celsius as it won't start.

I have also seen heat carts applies to engines on Q400's on morning headstarts, but as far as turning in and out I wouldn't think many complications should arise

It will be challenge for everyone. Schools might be closed (tomorrow they are open so far - I'm near by ORD in Park Ridge), some of activities for kids (indoor) were cancelled due to weather. Today schools were closed (NW burbs) due to snowfall. ORD had some cancellations as well.
Well, we will see. I will definetelly try to do some spotting on wednesday

747Whale wrote:

The sky isn't falling, and the world won't come to an end with slightly lower temperatures. Regarding APU's freezing solid...these APU's are cold soaked well below expected temperatures at ORD in the next few days; cold soaked this way with every landing. And yet they're started upon landing.

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Ehhhh, I don't agree 100%. I see where you're coming from but there's a big difference between an aircraft in flight and an aircraft that's been on a cold ramp overnight, unpowered. In flight is where an aircraft is designed to operate, things are running, heat is being directed where it needs to go, batteries, water lines etc. An aircraft sitting on the ramp overnight with no power or heat connected from a GPU and air cart can absolutely freeze to the point where damage occurs. Same as driving a car through a cold snap, if the engine is running, heat is on and you're moving, things will generally be ok, but if you stop and switch the car off, washer fluid can freeze, fuel can gel, brakes and tires can get stuck, door locks wont open etc. This is why in cities such as Fairbanks, AK cars are fitted with oil, battery and coolant plugs for overnight.

Aircraft are the same, it all depends on the options fitted. Common issues in the extreme cold are lav and water panels and lines freezing, brakes freezing, random computer faults etc. Airlines can order cold weather packages where the water lines and service ports are heat wrapped when the aircraft are on ground power, usually standard on larger aircraft, but sometimes an option on smaller ones. Most airlines have special cold weather ops procedures which can include things like making sure external power and heat are connected, running the APU if its very cold, securing ground equipment in bag rooms, hangars, etc.

People always like to point out "well they do it all the time in Siberia, Alaska, Canada etc" but those cities are equipped for it. Not that ORD doesn't get cold, but Alaska Airlines in Fairbanks will make sure every single piece of ground equipment it orders has a block heater that gets plugged in every night, where as in ORD, they might not which is fine 99% of the time, but on these extreme cold days can create problems.

Back to OP's question though, should you expect a major disruption? Probably not.... One off delays because the lav panel is frozen and they need to defrost it? Sure, bound to happen.

heathrow wrote:

I wouldn't think there would be any major impact if everyone knows what they're doing.

That's usually the issue in these situations. ANC, MSP, and BGR could get this cold and operations wouldn't be affected. But ORD is:
1. A much larger station
2. With personnel that are not used to operating in these temperatures.

Yes, if everyone knows what they're doing, it will be a non-issue. But they don't, so there will be issues.

The equipment is also a factor. Yes, if the equipment is properly maintained and prepped for cold ops, it will be a non-issue. But again, that's unfortunately not the case.

Life will go on. It won't be a meltdown, it will just be a slowdown. Ops will be affected, but not halted.

United787 wrote:

So I am flying back home tomorrow to ORD and everyone is anticipating delays because of the extreme cold. (High of 6 and Low of -21). I can understand the horrible conditions are tough for the ramp workers and might slow turn around time some. But would that have a noticeable affect on operations? What other elements are affected. What I can expect for delays and cancellations tomorrow?

Note: not talking about the snow, that finished today.

I was flying through ORD during the 2014 polar vortex and got stuck in Chicago for 2 nights. The cold lead to freezing fuel, which severely hampered operations even after all the snow came in. The temps this week are forecast to be as cold as 2014 if not colder. In my case, my plane from PHX came in late and I missed the last flight home, but the knock on effects lead to me having to stay a second night and eventually having to fly into an airport a 4 hour drive away from my final destination.

I wouldn't expect to be in Chicago for 3 days, but there's the potential for 1)very long lines 2) staff that are every bit as frustrated as the thousands of people they need to serve, and 3) the potential for your flight to be cancelled. Also, if you have to spend the night, don't count on the airlines being super helpful. AA was only able to give me a 15% off coupon for a hotel, and a lot of them around the airport were totally full.

Also you have to drain the potable water system as the water lines will freeze and crack.

Here are a few items:

• Potable Water Freezes. Airplanes parked overnight may need the tank drained
• Hoses to fill potable water can freeze, which may be difficult to service airplanes
• Rampers call in sick and must limit amount of time outside slowing down turns.
• Doors freeze shut. Cargo doors, APU Inlet Doors, Etc can get ice in them and won’t open
• Ground equipment breaks down.
• Tugs and Tractors can struggle to have adequate traction in ice, and temperatures this low prevent deicing chemicals from working. Airplanes can jackknife on a tug when sliding on ice

Here in STL it's not too bad. Looks to go down to around -2, not including wind chill.

Water servicing will be an issuse for sure. Hoses already frozen at many gates.

There will be some techical difficulties too if plane should stay overnight. For example a 777 requires hefty cold maintenance list to do. Even for a short period of without external heat or packs off water should be drained. Depend on engine core temperature gearbox heating may be required, and if the apu u/s; good luck.

All these are with perfect functioning plane or ground equipment any task with that cold will be 3-4 times will be difficult & slower.

jfklganyc wrote:

-40C is a standard limitation on aircraft

However, as others pointed out, the human limitation is much more of an issue

Embraer doesnt certify their jets past -40, but Boeing, Bombardier and MD-80s go much colder. See operations in FAI and Siberia.I am not sure about Airbus.

The other thing to remeber is that airplanes dont care about windchill, although the people servicing them might.

MSP guy here chiming in - although I got out and was SFO-based when I worked for the airlines.

We are lining up to be at -29 Wednesday morning, which is bad. But it has been worse. -34 is the all time MSP low - on January 19, 1970. Hit -32 in February of 1996. Northwest was the Buffalo Airways of the lower '48, and could run through all of this. But as others have said, deep subzero nights are equipment intensive and people intensive. When it was -34 back in 1970, there was much more slack in the operation, and more bodies to keep the show running. But after 40 years of cost control, there is less people redundancy and equipment redundancy. I bet DL will basically run smoothly at MSP, because it has the bones of the old NWA operation. But I would not want to be transiting ORD on Wednesday.

747Whale wrote:

BBDFlyer wrote:

Go put your smartphone in the freezer for 10 minutes and pull it out and see how it works. Now imagine that you left it in the freezer overnight and pull it out and imagine how it would work. That's what happens to many of the electronic and mechanical components of the airplane and also ground equipment.

It really isn't.

An aircraft is not a smart phone.

The sky isn't falling, and the world won't come to an end with slightly lower temperatures. Regarding APU's freezing solid...these APU's are cold soaked well below expected temperatures at ORD in the next few days; cold soaked this way with every landing. And yet they're started upon landing.

Ground power can be preheated. Huffers are available. Dipstick heating elements, too, and equipment will be run and warmed up before use. Antifreeze can be applied where needed. Deice equipment is available. These temperatures aren't unusual at places like Siberia and Fairbanks, Alaska, or much of Canada, and yet operations continue. Every day.

I can tell that you never work at such conditions. All items you described “can be” and “ available” never work as planned. People call sick, equipment wont start... I remember we tried more than 2 hours just a potable water fill.

N415XJ wrote:

Reminds me of the polar vortex of early 2014, during which I had the misfortune of passing through ORD. All flights except for a select few operated by larger aircraft were cancelled, meaning I was stuck in Chicago for 2 nights. Airline employees were telling me that fuel freezing was one of the reasons why flights were being cancelled, and IIRC the temperatures then were about the same as what's forecast in a few days.

Also,

OneX123 wrote:

It is my understanding that airplanes perform better in colder weather

This is technically true- colder air means better engine performance, more lift, etc due to how much denser the air is. However, cold air often comes coupled with low visibility, high winds, heavy precipitation, and bad taxiway/runway conditions. I'm not sure if there's a lot more snow forecast or if the rest of the week is just going to be cold, but I'd expect pretty bad operational delays.

Personal anecdote about aircraft performance in cold weather. On the day of my checkride it was a completely clear, beautiful day, and the temperature was about -5F IIRC. No matter how hard I tried I couldn't get my 172 to stall. Thankfully, the examiner was a great guy who didn't dock me points for it!

The polar vortex of 2014 was not as cold as they are predicting the weather will be over the next few days. During the 2014 polar vortex I was still on the ramp at ORD and with each passing day the number of call outs increase. I believe by the time we got to the 3rd or 4th day of the event in 2014 the number of call outs was near 50% on the ramp. With Wednesday's forecast high of -15 degrees F and near -50 below wind chill United already knows at least 30% of their out side workforce will not be at work and that is on top of people who have the day off and people on vacation and that is just UA employees. If we are talking about aircraft fuelers who are vendors I would bet anything the call out rate will probably top 60% for the amount of money they are being paid as fuelers I don't see them coming to work in those conditions.
I noticed some people remarks about aircrafts being tested in these subzero temps and I know they are but what many people don't think about is when the cargo pits are open those water lines and waste lines freeze quickly. We ran into this problem over an over during the polar vortex event in 2014, a standard turn time of 45-55 minutes is more than enough time to freeze the water and waste lines on the aircraft in these temperatures if both compartments are open even with the APU running. Wednesday for sure is going to be a challenge I wouldn't be surprised if UA places an embargo on all cargo coming into and out of all stations effected by this extreme cold snap just so the ramp can get those doors closed as quickly as possible or keep the doors close because at least on compartment is empty. Another benefit of a cargo embargo is it will limit the amount of time ramp personnel is outside which is just as important as keeping the pipes from freezing.

In 2014 United waited till it was to late to reduce the schedule which resulted in a lot of passengers being stranded at ORD for days. For now it looks like UA learned the lessons from 2014 by reducing the schedule with enough lead in time that most passengers in other parts of the country should still be able to make it to their final destination through other hubs .

747Whale wrote:

BBDFlyer wrote:

Go put your smartphone in the freezer for 10 minutes and pull it out and see how it works. Now imagine that you left it in the freezer overnight and pull it out and imagine how it would work. That's what happens to many of the electronic and mechanical components of the airplane and also ground equipment.

It really isn't.

An aircraft is not a smart phone.

The sky isn't falling, and the world won't come to an end with slightly lower temperatures. Regarding APU's freezing solid...these APU's are cold soaked well below expected temperatures at ORD in the next few days; cold soaked this way with every landing. And yet they're started upon landing.

Ground power can be preheated. Huffers are available. Dipstick heating elements, too, and equipment will be run and warmed up before use. Antifreeze can be applied where needed. Deice equipment is available. These temperatures aren't unusual at places like Siberia and Fairbanks, Alaska, or much of Canada, and yet operations continue. Every day.

I’ve had all of the issues that I mentioned. You’d think that a plane built in Canada would be more robust. On the absolute coldest days, they will usually have a huffer cart attached. But even when it’s below freezing but not necessarily that cold, some of these tired planes have trouble just getting some of the CRT’s powered up if they didn’t have a huffer cart attached. The CRJ also has issues starting the APU on cold mornings but the reverse start procedure seems to alleviate that. I’ve had more than one frozen APU door before. Our company requires us to have maintenance come out and unfreeze the door, and at an outstation that can take a few extra minutes in the morning.

Other issues I’ve had while flying in the great north:

We always drain the potable water at the end of the day, and if it’s just too cold, we don’t fill up the potable water in the morning the next day until we get to a hub like MSP, but I’ve seen tugs stuck on ice, I’ve had a ramp close due to ice and all inbound and outbound flights delayed or canceled till the ice was removed, and I’ve had a deice truck not start first thing in the morning. They got it started after half an hour but we still had to wait for the deice fluid to be warmed before deicing the aircraft.

The OP should really have mentioned MSP. How would that affect jet fuel, which would likely have lots of ice in it and be sluggish as it's close to the freezing point of Jet A? I could see a situation where most flights are reduced drastically for both DL and SY.

Things just break easier in the cold....I lived in GFK working for a major US freight company the last 8 years....you knew once it dipped below -30 something on some truck was going to break.

Yes planes are built to a much more specific specification and uses higher quality alloys than a truck, but they’re used to the temps at cruise when the engines are nice and toasty. Starting from a cold soak with engine oil as cold as it is, no bueno.

UNITED found out just the other day in Goose Bay, eh?

Aircraft that will remain over night (RON) for long periods will have their APU's running for the duration of their ground time. We are being instructed to have enough fuel in the tanks for about 8hrs of APU operation. Its to prevent the A/C from being cold soaked and that the APU will not have start issues. Aircraft with APU issues or deferrals are being discouraged from being routed into the affected area if possible. The airplanes will be fine, however its the ground people and equipment that may have issues (tugs starting, belt loaders working, ground and baggage handlers, fuelers...etc)