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Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 7:42 am
by reltney
How does extreme cold affect flight ops? I tell the F/O to bundle up for the outside preflight...I might toss him my gloves I carry when I was an F/O...


Seems I run into this every year and win the bet every time. If the tempature is 35F degrees and there is a 15kt bring the windchill to let’s say 23F degrees, Will water freeze? NO.. It is so funny when a pilot gets that wrong.... wind chill is a made up number. It “how it might feel on your skin opinion”, nothing more.. If your bundled up, you won’t know. The best is on the planes themselfs. We have a TAT gauge . Total air tempature . It is warmer than the Static Air tempature guage while flying. At cruise, the wind heats up the airframe. Yup. The Concorde grew the faster you flew because of the heat from the friction while it was -70F outside. Some planes have tempature limits not an actual VNE. So much for wind chill....

Just some Plane facts to share...

Cheers

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 3:12 pm
by frmrCapCadet
Airlines have done a lot better in recent years shutting down or reducing operation in the face of predicted bad weather conditions. Passengers are advised early, planes are parked or staged away from the affected areas. Recovery is likely planned before the shutdowns or reduced operations. Passengers rebook from the comfort of their homes or hotels. The horror scenes so common 20 years ago have become uncommon.

What I couldn't find online is the term for a cold shutdown (planned), and a hot shutdown (everything stopping in the middle of operations). I thought subway systems borrowed the term from nuclear plants, but am not finding it on google. Anyway, airlines also do cold shutdowns, which is the apt term for this one. But they could also to a cold shutdown if it is too hot. Language is plastic. LOL

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 3:27 pm
by Western727
SpaceshipDC10 wrote:
United787 wrote:
But would that have a noticeable affect on operations?


Smokey engines start at least on the RB211 and PW4460.


Kind of makes me wish the Tristar was still around. That'd be fun to watch in such conditions.

impact of the polar vortex on operations

Posted: Tue Jan 29, 2019 3:46 pm
by Worldair1
Anyone know how this will affect MSP & ORD operations? I remember working Alaska military charters back in the 90's as an ops controller. One time we had a paks trip were it was nearly 50 below zero. The Air Force ground techs were only allowed outside for 20 minute stretches at a time to fuel and load baggage. This was an MD11 and according to our dispatch at the time, we were operating the aircraft at the limits in that type of cold.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 4:53 pm
by MNgopher
As others have noted, it is not normal cold that is expected in many locations. Not unheard of, but certainly not what a "normal" day in places like MSP is either.

Ground equipment gets to be pretty fussy in the extreme cold. You will note in places like MSP its part of why they pretty much never shut equipment off in the cold. Diesel fuel in particular can be a problem in poorly maintained equipment - gelling and clogging fuel filter systems in particular. The diesel being delivered should be properly winterized for the conditions, but if the equipment hasn't been maintained it becomes a problem.

One measure of the how the airlines are doing (or think they are going to be doing) can be to look at the cancellations already on the board - Southwest in particular seems to be avoiding Chicago (a problem with the size of the Midway operation) and MSP too... Everything looks cancelled - makes you wonder why they are cancelled yet Delta and Sun Country are running their full slates out of MSP... Hmmmm...

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 5:11 pm
by Flighty
MSP and GFK would be among the coldest Lower 48 cities with jet service. But YWG has plenty of service and is substantially colder.

AFAIK as long as you can boot the aircraft up, the engines reach operating temp quickly, airplane warms up and no issue. I know E-170 had a problem booting up in cold temps.

The details of jet fuel freezing/gelling may come into play. By the book, Jet A would be almost frozen solid in Winnipeg today. Not sure how they deal with that.

What are the coldest cities with scheduled (daily) service?

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 5:55 pm
by readytotaxi
With these record lows predicted will the lavatory trucks be able to operate okay, could sure cause a few problems if not.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 8:26 pm
by MNgopher
Updating the cancellations, it appears that you can add Frontier and Spirit to the list of Airlines that have decided not to fly to MSP on Wednesday... A couple of cancellations to Chicago on United showing up as well.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 9:31 pm
by 747Whale
reltney wrote:
How does extreme cold affect flight ops? I tell the F/O to bundle up for the outside preflight...I might toss him my gloves I carry when I was an F/O...


Seems I run into this every year and win the bet every time. If the tempature is 35F degrees and there is a 15kt bring the windchill to let’s say 23F degrees, Will water freeze? NO.. It is so funny when a pilot gets that wrong.... wind chill is a made up number. It “how it might feel on your skin opinion”, nothing more.. If your bundled up, you won’t know. The best is on the planes themselfs. We have a TAT gauge . Total air tempature . It is warmer than the Static Air tempature guage while flying. At cruise, the wind heats up the airframe. Yup. The Concorde grew the faster you flew because of the heat from the friction while it was -70F outside. Some planes have tempature limits not an actual VNE. So much for wind chill....

Just some Plane facts to share...

Cheers


Wind chill is based on the ability of the wind to carry away body heat and it's affect on core temperature. Wind during cold weather does not have a ram rise or friction effect on people which warms them. While we do look at both TAT and SAT in flight for different purposes, wind chill is far more relevant to someone standing in the cold. It's the equivalent temperature to the effect on the person, animal, etc, in still air. A person standing in a 32F temperature with a 20 degree windshill will be affected the same as if they were in 12 degrees in still air.

Quite obviously, wind chill does not alter the physics of water nor cause water to freeze if the temperature is above freezing, but it will certainly increase the onset of hypothermia, or worse, and can rapidly increase exposure, rapidly lower core temperature, and decrease survivability when exposed.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 9:53 pm
by OneX123
reltney wrote:
How does extreme cold affect flight ops? I tell the F/O to bundle up for the outside preflight...I might toss him my gloves I carry when I was an F/O...


Seems I run into this every year and win the bet every time. If the tempature is 35F degrees and there is a 15kt bring the windchill to let’s say 23F degrees, Will water freeze? NO.. It is so funny when a pilot gets that wrong.... wind chill is a made up number. It “how it might feel on your skin opinion”, nothing more.. If your bundled up, you won’t know. The best is on the planes themselfs. We have a TAT gauge . Total air tempature . It is warmer than the Static Air tempature guage while flying. At cruise, the wind heats up the airframe. Yup. The Concorde grew the faster you flew because of the heat from the friction while it was -70F outside. Some planes have tempature limits not an actual VNE. So much for wind chill....

Just some Plane facts to share...

Cheers


Don't disagree with you, but don't understand why you're factoring in wind chill. AccuWeather has the temperature tomorrow morning at 8AM at -21F. That is not with wind chill and that is why I present the question initially. Seems to be 'extreme' cold. At least for operations at an airport the size of ORD.

Re: Will there be Disruptions due to ORD Temperature

Posted: Tue Jan 29, 2019 10:08 pm
by strfyr51
DocLightning wrote:
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.

I suspect United will have to run the ground heating for the overnight to keep the cabins around 55deg before the morning to knock the chill off the cabin. They can then run the APU to warm up the cabin before departure.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 10:26 pm
by DakotaFlyer
Just an update: All flights from Fargo and Grand Forks have been canceled due to freezing deicing fluid.
Some flights in/out of Bismarck and Minot have also been canceled.

Re: How does extreme cold affect flight ops?

Posted: Tue Jan 29, 2019 10:34 pm
by AirlineCritic
Aircraft will work, -14C is typical in winter in Scandavian airports, and -30C wouldn't be a huge issue either.

The usual kicker is de-icing, and runway clearing. Airports that don't have enough well-practiced capacity for these two will grind to a much slower pace, even if would be just a tiny bit of snow or cold that requires de-icing. Heathrow. I'm looking at you.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 1:10 am
by reltney
747Whale wrote:
reltney wrote:
How does extreme cold affect flight ops? I tell the F/O to bundle up for the outside preflight...I might toss him my gloves I carry when I was an F/O...


Seems I run into this every year and win the bet every time. If the tempature is 35F degrees and there is a 15kt bring the windchill to let’s say 23F degrees, Will water freeze? NO.. It is so funny when a pilot gets that wrong.... wind chill is a made up number. It “how it might feel on your skin opinion”, nothing more.. If your bundled up, you won’t know. The best is on the planes themselfs. We have a TAT gauge . Total air tempature . It is warmer than the Static Air tempature guage while flying. At cruise, the wind heats up the airframe. Yup. The Concorde grew the faster you flew because of the heat from the friction while it was -70F outside. Some planes have tempature limits not an actual VNE. So much for wind chill....

Just some Plane facts to share...

Cheers


Wind chill is based on the ability of the wind to carry away body heat and it's affect on core temperature. Wind during cold weather does not have a ram rise or friction effect on people which warms them. While we do look at both TAT and SAT in flight for different purposes, wind chill is far more relevant to someone standing in the cold. It's the equivalent temperature to the effect on the person, animal, etc, in still air. A person standing in a 32F temperature with a 20 degree windshill will be affected the same as if they were in 12 degrees in still air.

Quite obviously, wind chill does not alter the physics of water nor cause water to freeze if the temperature is above freezing, but it will certainly increase the onset of hypothermia, or worse, and can rapidly increase exposure, rapidly lower core temperature, and decrease survivability when exposed.



Absolutly correct. I did winter survival and live in DTW. Well versed. It doesn’t alter the physics of water however many don’t know that. They thing wind chill is actual temp. It is not as wa stated. You explained it better as I tend to be basic, thanks... If you bundle up, no chill.

Your awesome! Good post. Bundle up..

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 1:11 am
by jayunited
I waited to post this until it was officially announced. But starting yesterday UA enacted a plan that greatly reduces ORD's schedule on tomorrow January 30th and Thursday January 31st. For tomorrow January 30th UA will only have at most 11 flights departing per hour, these flights will be primarily hub-hub flights and our entire international schedule with a couple line stations thrown in. Most UAX flights have been canceled and UA has reduce the number of aircraft both mainline and express that will RON at ORD. Any aircraft that does RON will be parked in a heated hangar, aircraft remaining out in the elements will have the APU running. Starting with tonight all red eye flights have been delayed a few hours to limit the amount of time these aircraft spend on the ground at ORD UA has also delay some international arrivals into ORD (delays averaging about 2 hours). This will result in most narrow body aircraft spending about an hour on the ground and most widebodies a hour and a half maybe up to 2 hours. UA has also flown in extra ramp and C.S. crews from other hubs including LAX and IAH although I'm not sure why anyone from LAX or IAH would volunteer (no one was forced to come to ORD) to come work in -55 wind chill degree weather but they did. The extra crews are so ramp personnel can be rotated out quickly, the crews that works the inbound flights will not be the same crew that works the outbound flight. All cargo on narrow body aircraft has been embargoed, however UA is still accepting cargo on widebody international flights all of these measure should mean that ramp personnel should not be outside in these dangerous temperatures for more than 15 or 20 minutes at a time.

This plan here is a vast improvement over 2014 when UA had no plan at all and attempted to operate our full schedule and we ended up stranding passengers at ORD for over 2 days.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 2:06 am
by 747Whale
reltney wrote:
Absolutly correct. I did winter survival and live in DTW.


I taught survival.

Where it really gets interesting for those out in the cold is when clothing gets wet. It can go downhill fast.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 4:07 am
by TW870
jayunited wrote:
I waited to post this until it was officially announced. But starting yesterday UA enacted a plan that greatly reduces ORD's schedule on tomorrow January 30th and Thursday January 31st. For tomorrow January 30th UA will only have at most 11 flights departing per hour, these flights will be primarily hub-hub flights and our entire international schedule with a couple line stations thrown in. Most UAX flights have been canceled and UA has reduce the number of aircraft both mainline and express that will RON at ORD. Any aircraft that does RON will be parked in a heated hangar, aircraft remaining out in the elements will have the APU running. Starting with tonight all red eye flights have been delayed a few hours to limit the amount of time these aircraft spend on the ground at ORD UA has also delay some international arrivals into ORD (delays averaging about 2 hours). This will result in most narrow body aircraft spending about an hour on the ground and most widebodies a hour and a half maybe up to 2 hours. UA has also flown in extra ramp and C.S. crews from other hubs including LAX and IAH although I'm not sure why anyone from LAX or IAH would volunteer (no one was forced to come to ORD) to come work in -55 wind chill degree weather but they did. The extra crews are so ramp personnel can be rotated out quickly, the crews that works the inbound flights will not be the same crew that works the outbound flight. All cargo on narrow body aircraft has been embargoed, however UA is still accepting cargo on widebody international flights all of these measure should mean that ramp personnel should not be outside in these dangerous temperatures for more than 15 or 20 minutes at a time.

This plan here is a vast improvement over 2014 when UA had no plan at all and attempted to operate our full schedule and we ended up stranding passengers at ORD for over 2 days.


Thanks for the great post! This sounds like a very smart plan. I think the LAX and IAH people are coming because part of every airline worker loves logistical drama, and this is very much logistical drama. I remember when I flew for UA being on B concourse at ORD during a blinding snowstorm. A brand new AA 738 overran the one open runway, and then the whole airport closed. This is back when people used payphones, and there were huge lines for all the phones. It was totally fascinating - even though I waited in line at the crew desk for like 2 hours to get my reassignment and hotel information.

Of course DL is plowing through with full ops at MSP, but this is just because the ghost of Northwest keeps things going and this is a case that no one else can match.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 5:11 am
by seb146
Is there a difference in ops between prop and jet aircraft? Not many props are used much anymore, I am just curious.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 10:14 pm
by shamrock137
seb146 wrote:
Is there a difference in ops between prop and jet aircraft? Not many props are used much anymore, I am just curious.


Not used much for airlines but still greatly used in GA! Procedures are similar to a car. A block or oil heater might be plugged in overnight. Tanis is one of the major manufactures of these systems and they can be extremely comprehensive vs the block heater in a car. Heating elements can be placed in each cylinder, the oil sump, crankcase etc. These units are pretty powerful I was told the ones for our Cherokee 6's used about 400 watts. We used to put special cowling blankets on the engines and plugs in the cowl inlets so that the heat from the Tanis heater would stay in the engine cowling. They worked pretty well, when we took them off in the mornings the snow would usually be melted around the edges and the engines always fired right up. They also make propane or kerosene heaters that blow warm air in the engine cowl inlets but these aren't as good as an electric preheater as they don't heat evenly. The front two cylinders will get hot while the rear ones, especially in a 6 cyl and the interior parts of the engine block don't always get as warm.

Re: How does extreme cold affect flight ops?

Posted: Wed Jan 30, 2019 10:38 pm
by FlyHappy
TW870 wrote:
Of course DL is plowing through with full ops at MSP, but this is just because the ghost of Northwest keeps things going and this is a case that no one else can match.


probably not completely full ops, though pretty solid... the thing is, it isn't really a "ghost of Northwest" thing, more of just local culture accustomed to periodic severe winter days. Little things not as well ingrained in Detroit or Chicago - anticipating childcare for young kids (cuz schools are closed, after all), engine heaters, an understanding of what your body can or cannot tolerate, etc. I'd hazard to guess the "call in sick"/"can't make it in" rate in MSP is lower (though still high) than in DTW/CHI (though I fault no ramper anywhere for doing so).

I'm sure Winnipeg and Calgary also have very good operations, but are much smaller and easier to maintain continuity.
Perhaps Moscow is similarly effective, but I would not be surprised if it weren't.

Re: How does extreme cold affect flight ops?

Posted: Thu Jan 31, 2019 1:57 am
by TW870
FlyHappy wrote:
TW870 wrote:
Of course DL is plowing through with full ops at MSP, but this is just because the ghost of Northwest keeps things going and this is a case that no one else can match.


probably not completely full ops, though pretty solid... the thing is, it isn't really a "ghost of Northwest" thing, more of just local culture accustomed to periodic severe winter days. Little things not as well ingrained in Detroit or Chicago - anticipating childcare for young kids (cuz schools are closed, after all), engine heaters, an understanding of what your body can or cannot tolerate, etc. I'd hazard to guess the "call in sick"/"can't make it in" rate in MSP is lower (though still high) than in DTW/CHI (though I fault no ramper anywhere for doing so).

I'm sure Winnipeg and Calgary also have very good operations, but are much smaller and easier to maintain continuity.
Perhaps Moscow is similarly effective, but I would not be surprised if it weren't.


I actually think they ran almost everything. There were a few minor exceptions, like the 5am BJI-MSP and GFK-MSP cancelled, and FAR and BIS not opening until 10am for outbounds (they delayed the RONs until 10am). But otherwise mainline and regionals ran near normal. I completely agree, though, that everyone in MSP has a backup plan for severe cold. This is particularly true for ground transportation. Someone in ORD or DTW doesn't necessarily have a plan for getting the car going at -20. But in MSP, everyone knows how cold it can get until their car quits, and how to find a train/bus/uber etc. to get to work if the car is no-go. On the coldest night in ORD in 50 years, there is just less know-how to deal with it.

Re: How does extreme cold affect flight ops?

Posted: Fri Feb 01, 2019 12:23 pm
by remingtonbox
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.


Have you been around an airplane as more than a passenger? Current avionics are a big smartphone, they for sure freeze up and LCD/CRT screens take quite some time to come up to temperature. Lavs freeze over, GSE won't start. While I do agree its not the end of the world, it definitely causes for concern.

When I worked the ramp, a major midwest carrier would pay ramp people to sit in the airplane and start the APU every so often through the night so the water lines et al wouldn't freeze.

Re: Will there be Disruptions due to ORD Temperature

Posted: Sat Feb 02, 2019 12:19 am
by strfyr51
OneX123 wrote:
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?

Other than Icing? I don't think it's Airplanes. It's the people who Have to work around Said airplanes. Because they're the ones that are going to DO the Freezing!!

Re: How does extreme cold affect flight ops?

Posted: Sat Feb 02, 2019 1:26 am
by 747Whale
remingtonbox wrote:
Have you been around an airplane as more than a passenger?


A little bit. Mostly just as a pilot. And a mechanic. And an inspector. And instructor. And flight engineer. But only for the past few decades.

I do ride as a passenger on occasion, though.

And no, avionics are not smart phones.

Re: How does extreme cold affect flight ops?

Posted: Sat Feb 02, 2019 10:06 pm
by FredrikHAD
If the weather is extreme or not depends on the location. Here in Sweden, -22 F/-30 C would be extreme in the southern part, but common in the northern part. If you’re used to it and prepared for it, it’s not a big deal. If you’re not, it’s down right dangerous and even lethal. An airport that experiences -30 C for weeks evey year will have the equipment and the experience to handle it. Most airports don’t, so operations will be affected. Simple things like lacking gloves or proper clothing can cause injuries or inability to perform duties. Perhaps preparing for an extreme weather occurring at a specific location every 5 years is not worth the effort. Everybody wants operations as usual, and sitting in a nice warm terminal (or cockpit ;) ) looking out at rampers that struggle with ”simple” tasks may feel frustrating and even annoying, but anyone who’s tried to work in those temperatures knows it can be a real ordeal.

/Fredrik

Re: How does extreme cold affect flight ops?

Posted: Tue Feb 05, 2019 12:38 pm
by remingtonbox
747Whale wrote:
remingtonbox wrote:
Have you been around an airplane as more than a passenger?


A little bit. Mostly just as a pilot. And a mechanic. And an inspector. And instructor. And flight engineer. But only for the past few decades.

I do ride as a passenger on occasion, though.

And no, avionics are not smart phones.


I am not actually trying to start a fight, but the 650 and 750 GPS are 90% of the way to an iphone in operation

Re: How does extreme cold affect flight ops?

Posted: Tue Feb 05, 2019 3:49 pm
by stratclub
747Whale wrote:
remingtonbox wrote:
Have you been around an airplane as more than a passenger?


A little bit. Mostly just as a pilot. And a mechanic. And an inspector. And instructor. And flight engineer. But only for the past few decades.

I do ride as a passenger on occasion, though.

And no, avionics are not smart phones.

Sounds like me. Of course anyone that has zero aircraft experience except for being a passenger has a better idea about all things aviation than me. I'm trying to remember, both ends of an aircraft are sorta pointy, so which end arrives at the scene of an accident first?