Soxfan
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Preventing Icy Runways

Sat Dec 13, 2008 11:57 pm

Are runways at airports in colder climates built with different material to prevent ice from forming? I know there are snowplows, but what measures are taken to prevent a lot of ice from forming on the runways? Planes are really heavy, but I'm assuming they could still skid on the ice, would could present problems when taking off or landing.

Thanks!

Soxfan  Smile
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kcrwflyer
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RE: Preventing Icy Runways

Sun Dec 14, 2008 12:52 am



Quoting Soxfan (Thread starter):
I know there are snowplows, but what measures are taken to prevent a lot of ice from forming on the runways?

prayer....

I'm pretty sure ice and snow stick to asphalt the same as they would concrete or any other surface.
 
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tb727
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RE: Preventing Icy Runways

Sun Dec 14, 2008 1:06 am



Quoting Soxfan (Thread starter):
Planes are really heavy, but I'm assuming they could still skid on the ice, would could present problems when taking off or landing.

Yeah snow and ice do cause problems and you can slide around a bit. There are operational considerations that are different for each aircraft type such as different landing distance requirements for different types of contamination.

A key is to keep the snow off. If it's a dry snow it's a lot easier, but once it starts to melt and then refreeze you get problems. Grooved runways are always better in wet conditions in my opinion. Some airports even use chemicals to keep the runway surfaces from freezing over, however I have seen this backfire. I operate off of a long military runway on a regular basis that isn't grooved. Whenever they use chemicals to keep the water from freezing we always find ourselves sliding on the ends of the runway where all the rubber deposits are and it isn't a good feeling!
Too lazy to work, too scared to steal!
 
Soxfan
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RE: Preventing Icy Runways

Sun Dec 14, 2008 3:18 am

I guess people thought that heated runways were too expensive  Sad  Wink
Pilot: "Request push, which way should we face?" JFK Ground: "You better face the front, sir, or you'll scare the pax!"
 
pilotpip
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RE: Preventing Icy Runways

Sun Dec 14, 2008 4:08 am

Most airports use a liquid ice melt product.
DMI
 
roseflyer
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RE: Preventing Icy Runways

Sun Dec 14, 2008 4:56 am

Potassium based runway deicers are very common in the world. They lower the temperature that ice forms to prevent snow, ice and slush from forming on the runway. These are basically salts that will melt ice. They pose a huge hazard though to aircraft as they can cause corrosion. Just as on your car, runway deicers can corrode aluminum and other metal components on aircraft. I know how bad it is since I have to design parts to be able to handle the conditions of all airports in the world.
If you have never designed an airplane part before, let the real designers do the work!
 
unattendedbag
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RE: Preventing Icy Runways

Sun Dec 14, 2008 5:43 am



Quoting Soxfan (Thread starter):
but what measures are taken to prevent a lot of ice from forming on the runways?

take a look at this website:
http://www.cryotech.com/products/E36/index.php

e36 is used as a pre-treater for runways.

next, read this:
http://tinyurl.com/6dwdd2

Quoting RoseFlyer (Reply 5):
These are basically salts that will melt ice. They pose a huge hazard though to aircraft as they can cause corrosion.

I don't think so... Anything used on an aircraft or aircraft operating surface must NOT be corrosive to aircraft. While "potassium acetate and formate are salts, they must contain corrosian inhibitor packages to comply with SAE specifications" to be approved for airside applications.
Slower traffic, keep right
 
tdscanuck
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RE: Preventing Icy Runways

Sun Dec 14, 2008 7:32 am



Quoting UnattendedBag (Reply 6):
Quoting RoseFlyer (Reply 5):
These are basically salts that will melt ice. They pose a huge hazard though to aircraft as they can cause corrosion.

I don't think so... Anything used on an aircraft or aircraft operating surface must NOT be corrosive to aircraft. While "potassium acetate and formate are salts, they must contain corrosian inhibitor packages to comply with SAE specifications" to be approved for airside applications.

Although it makes a lot of sense to add corrosion inhibitors to deicing fluids, they absolutely *are* corrosive to aircraft. Potassium formate, especially, is mostly responsible for having to cadmium plate every connector in the wheel wells.

Tom.
 
roseflyer
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RE: Preventing Icy Runways

Sun Dec 14, 2008 4:41 pm



Quoting UnattendedBag (Reply 6):

I don't think so... Anything used on an aircraft or aircraft operating surface must NOT be corrosive to aircraft. While "potassium acetate and formate are salts, they must contain corrosian inhibitor packages to comply with SAE specifications" to be approved for airside applications.

When you are outside of the United States and certain areas with strict regulations, you do find a lot of very corrosive materials used on runways. Potassium Formate is one of the worst chemicals used as it will destroy unprotected aluminum overtime.
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MissedApproach
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RE: Preventing Icy Runways

Sun Dec 14, 2008 5:30 pm



Quoting Soxfan (Thread starter):
Are runways at airports in colder climates built with different material to prevent ice from forming?

No, standard building materials.

Quoting Soxfan (Thread starter):
what measures are taken to prevent a lot of ice from forming on the runways?

Snowplows & snowblowers are the first line of prevention for ice & snow build up.
Next, many airports use a runway sweeper, a rotory brush with steel bristles that removes snow & ice by abrasion- http://www.atifirst.com/sweeper.html
Airports also use a specially equipped truck to give braking indexes for the runways. When braking from a standard speed, a decelerometer generates a report that the controllers then pass to landing aircraft. Planes that have already landed will also report braking action to the controllers, though this is a bit subjective (ie. "poor", "fair", etc).

Salt is not used on the runways due to corrosion problems, & sand isn't used either since it will erode turbine blades, rotors & props. I have seen urea used in the ramp area.
http://www.meltsnow.com/products-airport-specialty-deicers.htm
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arffdude
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RE: Preventing Icy Runways

Mon Dec 15, 2008 1:48 am

We use potassium acetate at our airport. Same principle as sand, but much less corrosive.

Also with the new AC, a single braking action report of Nil closes the runway. The runway is also closed, if I'm not mistaken, by two consecutive poor reports.
 
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Starlionblue
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RE: Preventing Icy Runways

Mon Dec 15, 2008 6:24 am



Quoting MissedApproach (Reply 9):

Quoting Soxfan (Thread starter):
Are runways at airports in colder climates built with different material to prevent ice from forming?

No, standard building materials.

Quite. I imagine the concrete/asphalt mixes are a bit different to inhibit crack formation from repeated heating/cooling and ice formation.

The more days of snow/slush per year, the more well equipped an airport is to handle it. A day of snow in London equals absolute chaos, but since it doesn't happen that often it is not worth getting all the equipment. A day of snow in Helsinki is business as usual.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
meister808
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RE: Preventing Icy Runways

Mon Dec 15, 2008 5:34 pm

A nice layer of black paint on the runway does wonders to get ice to go away, even when its -40 outside.

-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
 
metroliner
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RE: Preventing Icy Runways

Mon Dec 15, 2008 7:37 pm

I thought the runway at OSL was heated - or is that just the road to OSL??  Smile
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boeing767mech
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RE: Preventing Icy Runways

Tue Dec 16, 2008 12:27 am



Quoting RoseFlyer (Reply 8):
When you are outside of the United States and certain areas with strict regulations, you do find a lot of very corrosive materials used on runways. Potassium Formate is one of the worst chemicals used as it will destroy unprotected aluminum overtime.

If we have an airplane that has taken off from an airport that used anything besides sand on the runway, it is taken out of service to a belly and gear well wash at it's next overnight in wamr weather.

David
Never under-estimate the predictably of stupidty
 
pilotpip
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RE: Preventing Icy Runways

Tue Dec 16, 2008 12:46 am



Quoting MissedApproach (Reply 9):
Snowplows & snowblowers are the first line of prevention for ice & snow build up.
Next, many airports use a runway sweeper, a rotory brush with steel bristles that removes snow & ice by abrasion- http://www.atifirst.com/sweeper.html
Airports also use a specially equipped truck to give braking indexes for the runways. When braking from a standard speed, a decelerometer generates a report that the controllers then pass to landing aircraft. Planes that have already landed will also report braking action to the controllers, though this is a bit subjective (ie. "poor", "fair", etc).

Salt is not used on the runways due to corrosion problems, & sand isn't used either since it will erode turbine blades, rotors & props. I have seen urea used in the ramp area.
http://www.meltsnow.com/products-air...s.htm

Snowblowers work great when it's cold enough for the snow to be dry. Here in STL we're not so lucky. They have to use a lot of liquid deicer.

Grooved runways also help.
DMI
 
MissedApproach
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RE: Preventing Icy Runways

Tue Dec 16, 2008 4:31 am



Quoting Pilotpip (Reply 15):
They have to use a lot of liquid deicer.

Do you mean glycol, or a brine solution?
Can you hear me now?
 
Soxfan
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RE: Preventing Icy Runways

Tue Dec 16, 2008 5:03 am

Thanks for all the responses! There's a lot of great detail and I appreciate it.  Smile

Another thing to consider is the use of snowplows, as they could potential dent up the runway from the sharp blades. Is this likely to have a significant effect over time, or are the runways repaved/is something done every so often to limit the effect of snowplow blades? Or, could the blades have no effect at all?
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Starlionblue
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RE: Preventing Icy Runways

Tue Dec 16, 2008 5:29 am



Quoting Soxfan (Reply 17):
Another thing to consider is the use of snowplows, as they could potential dent up the runway from the sharp blades. Is this likely to have a significant effect over time, or are the runways repaved/is something done every so often to limit the effect of snowplow blades? Or, could the blades have no effect at all?


Plows are used all the time in cold climates. Practically a must with heavy snowfall. I have never heard of the denting problem on runways but I guess it is possible.

It's quite a sight to see 5 plows driving in formation down a runway!
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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BreninTW
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RE: Preventing Icy Runways

Tue Dec 16, 2008 7:26 am



Quoting Soxfan (Reply 17):
Another thing to consider is the use of snowplows, as they could potential dent up the runway from the sharp blades. Is this likely to have a significant effect over time, or are the runways repaved/is something done every so often to limit the effect of snowplow blades? Or, could the blades have no effect at all?

Plow blades generally have a foot or wheel that keeps the blade at a constant height. They are fitted on the plow frame very close to the blade itself and they ensure that the blade does not bounce on the surface (as you would get when a blade is allowed to run freely on the surface -- it will "dig in" and then cause damage to the surface).
 
A333TS
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RE: Preventing Icy Runways

Tue Dec 16, 2008 2:42 pm

This might be a stupid comment, but I was under impression that runways had warm or hot water pipes under the concrete to reduce ice formation on the runway. I don’t have any evidence that this is actually happening nor have I read this anywhere; this is just something I thought would make sense. I know that this method is probably very expensive investment but over 50 years in the northern countries around the world it might pay off. May be this wasn’t done because of the thermal shock to the pavement.

In my underground parking garage we use this system for the ramp that leads in and out of the garage, but that stretch is only 25ft and runways are 10000ft.


A333TS
 
tdscanuck
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RE: Preventing Icy Runways

Tue Dec 16, 2008 5:24 pm



Quoting A333TS (Reply 20):
This might be a stupid comment, but I was under impression that runways had warm or hot water pipes under the concrete to reduce ice formation on the runway.

Technically it would work just fine, as your parking garage ramp and lots of private driveways demonstrate. However, I suspect the energy costs are crippling...the thermal mass of an entire runway is huge.

Tom.
 
A333TS
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RE: Preventing Icy Runways

Wed Dec 17, 2008 3:34 am



Quoting Tdscanuck (Reply 21):

If there is a nuclear power plant near the airport that requires a lot of cooling to cool off the reactors, it might work, and then there will be no concerns for the energy use. But I don’t know any nuclear power plants that are build in close vicinity to the airport.  alert 

There might be some safety regulations about building a nuclear reactor at the airport, but I’m not 100% sure.  Silly

A333TS
 
Soxfan
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RE: Preventing Icy Runways

Wed Dec 17, 2008 3:51 am

Would the weight of the plane have any effect on the pavement between the wheels and the hot-water pipes? I doubt there is, but too much pressure and wearing down the pavement could have an effect on the pipes if they're not deep enough. Please correct me if I'm wrong (as I probably am).

Quoting A333TS (Reply 20):
This might be a stupid comment

NO (or almost no) comment is stupid here! That's what I think the forum is for, to any questions and comments answered _related to the topic_, as your comment was.
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rwessel
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RE: Preventing Icy Runways

Wed Dec 17, 2008 9:40 am



Quoting Tdscanuck (Reply 21):
Technically it would work just fine, as your parking garage ramp and lots of private driveways demonstrate. However, I suspect the energy costs are crippling...the thermal mass of an entire runway is huge.

Coincidentally, the folks down the hall in our office building (totally different company, we have nothing to do with them) claim to have products to do just that. www.hotmesh.com

They seem to claim power consumption on the order of 150W/sq m. For a 12000ftx200ft runway (about 225k sq m), that works out to about 34MW. Which is a lot, but not unreasonable (in the sense that getting that sized feed out of your local power company is not a big deal). You probably don't have to run the whole thing at full power all the time either - melt in sections, and then heat the melted sections at a lower rate to keep them clear.
 
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Starlionblue
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RE: Preventing Icy Runways

Wed Dec 17, 2008 2:20 pm



Quoting Rwessel (Reply 24):

They seem to claim power consumption on the order of 150W/sq m. For a 12000ftx200ft runway (about 225k sq m), that works out to about 34MW. Which is a lot, but not unreasonable (in the sense that getting that sized feed out of your local power company is not a big deal). You probably don't have to run the whole thing at full power all the time either - melt in sections, and then heat the melted sections at a lower rate to keep them clear.

Interesting. But how much does that cost compared to plows and de-icing agents?
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
chrisMUC
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RE: Preventing Icy Runways

Wed Dec 17, 2008 5:47 pm



Quoting Metroliner (Reply 13):
I thought the runway at OSL was heated - or is that just the road to OSL??

unfortunately "only" the apron is heated.
In fact, OSL is the only airport where I've ever landed on a thick layer of snow.
They compact it and add some sand, BA for a B737 is almost good then.
 
rwessel
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RE: Preventing Icy Runways

Wed Dec 17, 2008 10:03 pm



Quoting Starlionblue (Reply 25):
But how much does that cost compared to plows and de-icing agents?

Well, electricity in bulk runs around $50/MW-hr, so if you ran a 34MW deicing grid for 1000 hours per year, it would cost you about $1.7M.

That's almost 42 entire days, which seems rather high. Chicago (at the ORD weather station), for example, averages measurable snow (a tenth of an inch or more) on about 27.4 days each winter, only about 9.2 days get more than an inch. Assuming the mats get turned on for an average of four hours for the under-an-inch days, and twelve hours for the inch-or-more days, you get 183 hours, or about $310K. And even that seems generous.

OTOH, the initial installation cost will need to be capitalized. And from a bit more digging around their web site, they have several different types of heating meshes, it's not entirely clear which would be applicable to a runway (although they seem to imply that the lower powered versions apply, at least in some cases), but the highest power version draws 900W/sq m (although those appear to be capable of generating surface temps up to 350F), or six times the rate I quoted from the more obvious section of the web site.

On the third hand, one runway with that kind of heating grid could probably handle the load of two or three similar runways being plowed during a snowstorm.
 
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Starlionblue
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RE: Preventing Icy Runways

Wed Dec 17, 2008 11:49 pm

That's less money than I thought it would cost. However as you say there may not be a lot of places that get that many days of actual snowfall. Winter is longer but once the snow has fallen and is plowed away that's it. Hmmm...
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
packcheer
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RE: Preventing Icy Runways

Fri Dec 19, 2008 9:15 pm

It seems as though a system like that could be better used to prevent the ice/snow from accumulating in the first place. I live in NC and quite often we get snow that doesn't stick to road ways becuase the asphalt and concrete hold temperature better. If you turned the heater on a very low setting just enough to keep the concrete slightly warmer, it would prevent formation. Energy would be extremely high to melt already existing ice
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Starlionblue
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RE: Preventing Icy Runways

Fri Dec 19, 2008 11:13 pm



Quoting Packcheer (Reply 29):
It seems as though a system like that could be better used to prevent the ice/snow from accumulating in the first place. I live in NC and quite often we get snow that doesn't stick to road ways becuase the asphalt and concrete hold temperature better. If you turned the heater on a very low setting just enough to keep the concrete slightly warmer, it would prevent formation. Energy would be extremely high to melt already existing ice

If you get 50cm of snow in a day, there's no way a heated roadway or runway will keep that from staying on the ground. Eventually, it will melt, but in practice you need plows.

As for asphalt and concrete holding temperature better, that's also a short term phenomenon in colder climates.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
pilotpip
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RE: Preventing Icy Runways

Sat Dec 20, 2008 12:56 am



Quoting MissedApproach (Reply 16):
Do you mean glycol, or a brine solution?

Talking to our ops guys, they use Potassium Acetate. Also told they're seriously rationing it right now because the company that makes it is on strike.

They're exploring other options. We've had three nights of sleet and freezing rain in the last week. The taxiways were a mess before the weather warmed up today.
DMI
 
rwessel
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RE: Preventing Icy Runways

Sat Dec 20, 2008 11:44 am



Quoting Starlionblue (Reply 30):
If you get 50cm of snow in a day, there's no way a heated roadway or runway will keep that from staying on the ground. Eventually, it will melt, but in practice you need plows.

Fresh snow is typically 5-15% the density of water, so 50cm of snow would be 7.5cm of water at the high end of the range. A sq m of that would be 75kg. Melting that much snow would take about 25MJ of energy for the solid/liquid phase change. Let's also assume that the snow started at -15C (5F - it’s uncommon to get a lot of snow when it’s colder than that). First heating the 75kg of snow from -15C to 0C would take an additional 4.7MJ. Let's round up and call it 30MJ. 30MJ is about 55 hours of 150W. So at the high end (15%) this isn’t going to happen. OTOH, at the low end, if most of the energy makes it to the snow, you ought to be able to keep up.
 
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Starlionblue
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RE: Preventing Icy Runways

Sat Dec 20, 2008 1:32 pm

Thanks for the math Rwessel. The question is now: Is it worth it?

In future, place nuclear power plants next to airports. They always need to cool water and the heat should be used for something.  Wink
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
qblue
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RE: Preventing Icy Runways

Sat Dec 20, 2008 10:18 pm

Snow plows use hard rubber as there blade for airport use. When they wearout they just bolt on new ones. The potash mines are back to work now so more chemicals will be available soon. It will take several week to get production up to meet demand. Some airports are sharing chemicals like YEG sending YVR some liquid chemical becase YVR blew all theirs on the first snow fall with no snow crew on stand-by.
 
Alessandro
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RE: Preventing Icy Runways

Sun Dec 21, 2008 4:13 pm

Quoting A333TS (Reply 20):
This might be a stupid comment, but I was under impression that runways had warm or hot water pipes under the concrete to reduce ice formation on the runway. I don’t have any evidence that this is actually happening nor have I read this anywhere; this is just something I thought would make sense. I know that this method is probably very expensive investment but over 50 years in the northern countries around the world it might pay off. May be this wasn’t done because of the thermal shock to the pavement.

In my underground parking garage we use this system for the ramp that leads in and out of the garage, but that stretch is only 25ft and runways are 10000ft.


A333TS

Well, when an airliner lands it´s a big punch to the ground and the pipes would most likely crack after a while so I doubt it would be such a grand idea to do so on runways, on taxiways yes,
especially in countries with surplus energy like Iceland.

[Edited 2008-12-21 08:17:44]
From New Yorqatar to Califarbia...
 
A333TS
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RE: Preventing Icy Runways

Mon Dec 22, 2008 4:24 am



Quoting Alessandro (Reply 35):

You are correct I completely forgot about the forces that are being applied by the aircraft on the runway during the landing. Taxiways might actually be a good idea.

A333TS

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