ndhair37
Topic Author
Posts: 149
Joined: Sun Apr 28, 2013 9:06 pm

UA 738 Off Runway

Tue Jan 05, 2016 3:42 pm

According to media, a United Airlines B738 has slid off the end of an extremely icy runway at Spokane.

The aircraft is N38268 on flight UA812.

Runway seemingly now blocked.
 
User avatar
LAXintl
Posts: 24005
Joined: Wed May 24, 2000 12:12 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 3:48 pm

From the desert to the sea, to all of Southern California
 
777X
Posts: 854
Joined: Fri Dec 19, 2014 12:44 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 3:56 pm

Not a good week for UA 737s...
 
toltommy
Posts: 2723
Joined: Tue Dec 09, 2003 9:04 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 3:57 pm

Extremely icy? Gotta love the media. Wonder what the reported braking action was before landing.
A300/A310/A319/A320/A321/A332/A333/707/712/727/732/733/734/735/738/739/752/753/762/763/764/772/789/DC8/DC9-10/30/40/50/MD81/83/87/88/90/L1011-/250/500/CRJ200/440/700/900/EMB135/140/145/170/175/190/328Jet/F70/SF3/BE1/J31
 
jetskipper
Posts: 500
Joined: Tue Jun 12, 2001 1:50 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:13 pm

Quoting toltommy (Reply 3):

Flight 812 was taxing out for departure. It's unclear whether the excursion was on a taxiway or the runway. It's not common for Air Traffic Control to report taxiway braking action.
 
User avatar
redzeppelin
Posts: 1146
Joined: Wed Feb 08, 2012 4:30 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:18 pm

http://www.krem.com/story/news/local...unway-at-spokane-airport/78297952/

Quote:
Director of Marketing and Public Affairs for Spokane Airport, Todd Woodward, confirmed the slide in an e-mail.

"At approximately, 6:00 A.M. Pacific Time, a United Airlines 737 aircraft slid-off the southern end of the holding area of Taxiway A.. No injuries have been reported. The Airport is assisting United with off-loading the passengers and getting the aircraft back on the hard surface. This situation is developing."

KREM 2 Meteorologist Katie Boer posted a video that shows freezing rain landing directly over the Airport.
 
Sooner787
Posts: 2635
Joined: Thu Jul 18, 2013 1:44 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:20 pm

Que the Patroni jokes in 3...2...1.. 
 
iahcsr
Posts: 4777
Joined: Fri Jun 04, 1999 2:59 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:31 pm

The UA App still shows ' taxiing to the runway ' ..
Working Hard, Flying Right Friendly....
 
Desh
Posts: 204
Joined: Wed Aug 24, 2005 10:52 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:36 pm

Here is another one from the twitters

https://twitter.com/caseylundkxly/status/684408810618802176
"History is merely a list of surprises. It can only prepare us to be surprised yet again." - Kurt Vonnegut
 
Brick
Posts: 1677
Joined: Wed Aug 04, 1999 11:08 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 4:59 pm

Wow, it slid sideways. Icy indeed...
A noble spirit embiggens the smallest man...
 
User avatar
GEG
Posts: 308
Joined: Wed Oct 20, 2004 11:45 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:33 pm

Quoting toltommy (Reply 3):
Extremely icy? Gotta love the media.

With the freezing rain we had overnight all of Spokane was a skating rink this morning, out by the airport it was horrible.

[Edited 2016-01-05 09:36:47]
I have no idea what I'm doing...
 
User avatar
tlecam
Posts: 1474
Joined: Tue Jul 23, 2013 1:38 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:36 pm

Glad to hear that there were no injuries. I'll also remember this the next time I'm grumbling about weather delays.
BOS-LGA-JFK | A:319/20/21, 332/3, 346 || B:717, 735, 737, 738, 739, 752, 753, 762, 763, 764, 787, 772, 744 || MD80, MD90
 
Flaps
Posts: 1591
Joined: Sat Feb 05, 2000 1:11 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:45 pm

Quoting iahcsr (Reply 7):
The UA App still shows ' taxiing to the runway ' ..

Which, "technically speaking" is 100% correct. Departed the gate and has yet to arrive at either the runway or return to the gate.

  
 
IADCA
Posts: 2034
Joined: Mon Feb 26, 2007 12:24 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:50 pm

Quoting toltommy (Reply 3):

Extremely icy? Gotta love the media. Wonder what the reported braking action was before landing.

If the flight listed in the OP is right and the photo in reply 1 is right, it looks pretty doubtful that there was much braking at all, and none before landing as the flight hadn't departed yet.
 
b747400erf
Posts: 3135
Joined: Wed Jun 19, 2013 4:33 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:53 pm

Quoting g500 (Reply 8):

Qantas doesn't have to land on ice-snow covered runways like this one.

You think it doesn't snow in the southern hemisphere?
 
toltommy
Posts: 2723
Joined: Tue Dec 09, 2003 9:04 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:55 pm

Quoting jetskipper (Reply 4):
It's not common for Air Traffic Control to report taxiway braking action.

Perhaps not, but I always included it in my FICON. A quick call to the tower usually gets a report. If the van ride was interesting, I know I'd be asking before I started taxi.
A300/A310/A319/A320/A321/A332/A333/707/712/727/732/733/734/735/738/739/752/753/762/763/764/772/789/DC8/DC9-10/30/40/50/MD81/83/87/88/90/L1011-/250/500/CRJ200/440/700/900/EMB135/140/145/170/175/190/328Jet/F70/SF3/BE1/J31
 
Cubsrule
Posts: 14175
Joined: Sat May 15, 2004 12:13 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 5:59 pm

Quoting B747400ERF (Reply 15):
You think it doesn't snow in the southern hemisphere?

Does any big city in Australia get snow? It would appear that Perth (proper) never has. I can't find record of snow in the past 100 years in Sydney, or Brisbane, and Wikipedia says it last snowed in Melbourne in 1951. Some media reports suggest that Canberra gets snow every decade or so, but that's all I can find.
I can't decide whether I miss the tulip or the bowling shoe more
 
DualQual
Posts: 709
Joined: Sun Mar 05, 2006 6:10 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 6:29 pm

Quoting Cubsrule (Reply 17):

I'll wager it has snowed on QANTAS at least once at JFK   but your point does stand that their exposure to such conditions is likely more limited than a lot of world wide carriers.

[Edited 2016-01-05 10:30:16]
There's no known cure for stupid
 
FlyHossD
Posts: 1974
Joined: Mon Nov 02, 2009 3:45 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 6:59 pm

Quoting desh (Reply 9):
Here is another one from the twitters

https://twitter.com/caseylundkxly/status/684408810618802176
Quoting Brick (Reply 10):
Wow, it slid sideways. Icy indeed...

Yes, slid sideways. Considering that it wasn't terribly windy, the conditions on the taxiway must have been exceptionally poor. I wonder what the airport was doing about the conditions?
My statements do not represent my former employer or my current employer and are my opinions only.
 
User avatar
FredrikHAD
Posts: 448
Joined: Thu Aug 06, 2015 9:44 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:01 pm

Looks about as slippery as one winter morning at KRF (don't be embarrassed if you don't know where that is, nobody does) when I idled the fire engine out of the garage, immediately started braking on the apron (3 km/h?), just stopping on the edge to the grass field to make the morning test of the water cannon. On the way back (on idle only), I had a really nice drifting turn in the slight "uphill" slope to the garage.

I can well imagine that it was very slippery on the taxiways. No anti-skid is going to save you from sliding off the tarmac sideways!

Look at the angle it slid out of the tarmac at. Looks like it rotated 120 degrees before the MLG went off!

/Fredrik

[Edited 2016-01-05 11:03:13]
 
flightsimer
Posts: 1052
Joined: Mon Aug 17, 2009 5:34 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:18 pm

Quoting Flaps (Reply 13):
Which, "technically speaking" is 100% correct. Departed the gate and has yet to arrive at either the runway or return to the gate.

I was going to say the same exact thing lol.
Commercial / Airline Pilot
 
IADCA
Posts: 2034
Joined: Mon Feb 26, 2007 12:24 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:31 pm

Quoting Cubsrule (Reply 17):

Does any big city in Australia get snow? It would appear that Perth (proper) never has. I can't find record of snow in the past 100 years in Sydney, or Brisbane, and Wikipedia says it last snowed in Melbourne in 1951. Some media reports suggest that Canberra gets snow every decade or so, but that's all I can find.
QF doesn't only fly to big cities in Australia, though. They fly 737s to ZQN, where it does snow, in addition to a handful of longhaul destinations where it snows. There's sure a lot less than for UA (and indeed, no comparable hubs to EWR, ORD, or even IAD), but it's not a totally foreign concept.

Incidentally, mentioning Brisbane and snow reminded me of being on a hike in Fiordland in New Zealand a few years back and running into some rather petrified Aussies from Brisbane who were having their first experience ever of snow on an exposed mountain saddle with 100-foot drops on either side. Good times.

[Edited 2016-01-05 11:32:11]
 
User avatar
kgaiflyer
Posts: 2741
Joined: Sat Jul 19, 2008 3:22 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:33 pm

From Spokane's Channel 2 news

"United officials confirmed 166 passengers were on board and seven crew members. Flight operations brought out a ladder to get them off of the rear of the plane shortly after 7:00 a.m.

Passengers described the process of getting off the plane as slow, but said everyone remained calm there was not any panic among the passengers or flight crew.

Officials took passengers off the plane in groups of 10, placed them on a shuttle bus and brought them back to the terminal."
 
User avatar
litz
Posts: 2350
Joined: Wed Dec 24, 2003 6:01 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:53 pm

The way that slid kinda reminds me of some infamous video from Atlanta back in either the '86 or '93 ice storm, where one of the local TV reporters was reporting from the shoulder of the main interstate through the city (a 6-8 lane monstrosity called the Downtown Connector), and behind him you could see ... almost like it was in slow motion ... a MARTA transit bus slowly spinning a full 360, and ending up neatly parallel parked on the edge of the road.

With the reporter totally oblivious to what was going on behind him.

Moral is simple : large massive object + ice + momentum = very bad news.
 
Cubsrule
Posts: 14175
Joined: Sat May 15, 2004 12:13 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 7:59 pm

Quoting IADCA (Reply 22):
They fly 737s to ZQN, where it does snow, in addition to a handful of longhaul destinations where it snows. There's sure a lot less than for UA (and indeed, no comparable hubs to EWR, ORD, or even IAD), but it's not a totally foreign concept.

I didn't mean to suggest that it was foreign, but I was surprised that anyone would dispute that QF has a lot less experience with snow than most US carriers.
I can't decide whether I miss the tulip or the bowling shoe more
 
birdbrainz
Posts: 505
Joined: Fri May 27, 2005 6:57 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 8:03 pm

Quoting g500 (Reply 8):
Qantas doesn't have to land on ice-snow covered runways like this one.

Point taken, but nor do the SE Asia budget carriers have to deal with ice, either, and as a group, they've bent their share of metal.

QANTAS is a great airline, but has had its share of incidents, and been fortunate not to have paid dearly for them.
A good landing is one you can walk away from. A great landing is if the aircraft can be flown again.
 
seat1a
Posts: 527
Joined: Mon Jan 11, 2010 7:52 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 8:09 pm

What happens to the UA 737 next? Will UA fly maintenance to GEG for evaluation and repairs there or will they ferry to SFO or DEN? Curious what's involved with this process. Thanks!
 
INFINITI329
Posts: 2489
Joined: Mon Jul 02, 2012 12:53 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 8:45 pm

Quoting Flaps (Reply 13):
Which, "technically speaking" is 100% correct. Departed the gate and has yet to arrive at either the runway or return to the gate.

This made my day lol
 
User avatar
Boeing778X
Posts: 3268
Joined: Sun Nov 17, 2013 7:55 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 8:48 pm

Dammit    Not good at all.

Hopefully the damage wasn't severe.
United Airlines: $#!ttin' On Everyone Since 1931
 
AzoresLover
Posts: 756
Joined: Sun Jun 27, 2004 4:43 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 9:17 pm

This incident makes me wonder...apparently some level of winds, heavy ice rain directly over the airport, plane sliding sideways off the holding area at the end of a taxiway...

Not that this had any effect on what happened, just curious...was the plane deiced prior to its taxi? How long would it take in a freezing rain for the buildup of ice on the plane becomes too dangerous to fly? I know that a deiced plane can go a fairly long period of time in snow and still be safe. But ice rain?????

Can someone here address the issue of ice rain on aircraft?

Thanks.
Those who want to do something will find a way; those who don't will find an excuse.
 
User avatar
litz
Posts: 2350
Joined: Wed Dec 24, 2003 6:01 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 9:20 pm

the picture linked in reply 1 looks dire, but the one in reply 9 seems much better. It's just a sideways slide into the snow covered grass, per that pic. It's still upright, on its gear, no engines scooping up snow/dirt, etc.

In theory, they should be able to just tow it back onto the concrete, wash the gear off, do an inspection, etc.

(of course, that's "in theory" ...)

Mind you, they gotta find something to tow it with that can manage traction in that mess ...
 
Ryanair01
Posts: 456
Joined: Fri Dec 27, 2013 9:27 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 11:35 pm

Quoting g500 (Reply 8):
Qantas doesn't have to land on ice-snow covered runways like this one.

Erm......
http://www.abc.net.au/news/2015-07-1...s-across-eastern-australia/6614200

 
User avatar
DocLightning
Posts: 21634
Joined: Wed Nov 16, 2005 8:51 am

RE: UA 738 Off Runway

Tue Jan 05, 2016 11:43 pm

Passenger said that the excursion occurred during/immediately after a turn. Looks as if they went to turn and then the aircraft decided to go skating.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
-Carl Sagan
 
coolian2
Posts: 2483
Joined: Sun Oct 22, 2006 3:34 pm

RE: UA 738 Off Runway

Tue Jan 05, 2016 11:49 pm

Not to mention Christchurch or Auckland every 50 years
Q300/ATR72-600/737-200/-300/-400/-700/-800/A320/767-200/-300/757-200/777-300ER/
747-200/-300/-400/ER/A340-300/A380-800/MD-83/-88/CRJ-700/-900
 
RickNRoll
Posts: 1836
Joined: Fri Jan 06, 2012 9:30 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 12:32 am

Quoting IADCA (Reply 22):
Incidentally, mentioning Brisbane and snow reminded me of being on a hike in Fiordland in New Zealand a few years back and running into some rather petrified Aussies from Brisbane who were having their first experience ever of snow on an exposed mountain saddle with 100-foot drops on either side. Good times.

Australians unfortunately have a reputation for getting into trouble with New Zealand weather. It's due east of Australia but a lot more mountainous.

And yes, QANTAS does not have to deal with extreme winter conditions nearly as often as other airlines do. In fact, some major airports don't even have CATIII landing set up.
 
Viscount724
Posts: 19316
Joined: Thu Oct 12, 2006 7:32 pm

RE: UA 738 Off Runway

Wed Jan 06, 2016 12:56 am

Quoting RickNRoll (Reply 35):
And yes, QANTAS does not have to deal with extreme winter conditions nearly as often as other airlines do. In fact, some major airports don't even have CATIII landing set up.

Canada, where snow is common for half the year (longer in the north), only has 4 airports with CATIII (YVR/YYC/YYZ/YYT) and one of those (YVR) rarely has much snow.

Only 5 other airports in Canada have CATII (YHM/YHZ/YMX/YUL/YWG).
 
benjjk
Posts: 370
Joined: Fri Aug 08, 2014 4:29 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 1:35 am

Not sure how this conversation got onto Qantas but it's fair to say that none of the Australian airports experience anything close to the level of snow encountered in many US ports.

Quoting birdbrainz (Reply 26):
Point taken, but nor do the SE Asia budget carriers have to deal with ice, either, and as a group, they've bent their share of metal.

Nope, just daily tropical thunderstorms and mountainous terrain. Arguably worse than snow...
 
ZBBYLW
Posts: 1623
Joined: Wed Nov 01, 2006 8:17 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 4:01 am

Quoting Viscount724 (Reply 36):

And better yet our capital airport, on one of the more frequently used runways only has an NDB or RNAV for those aircraft capable.
Keep the shinny side up!
 
rbavfan
Posts: 3431
Joined: Fri Apr 17, 2015 5:53 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 4:04 am

Quoting Ryanair01 (Reply 32):

Has to be an old story as its summer there now.
 
User avatar
DocLightning
Posts: 21634
Joined: Wed Nov 16, 2005 8:51 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 4:12 am

Quoting benjjk (Reply 37):

Nope, just daily tropical thunderstorms and mountainous terrain. Arguably worse than snow...

They both have issues. Thunderstorms and mountainous terrain are a risk to aircraft in flight. Snow and ice is a risk to aircraft landing and maneuvering on the ground.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
-Carl Sagan
 
roseflyer
Posts: 9602
Joined: Fri Feb 13, 2004 9:34 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 4:16 am

Are there any more pictures?

Why is this thread so off topic and talking about wants and Australia weather? US winter has been hitting UA hard.
If you have never designed an airplane part before, let the real designers do the work!
 
flightsimer
Posts: 1052
Joined: Mon Aug 17, 2009 5:34 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 6:41 am

Quoting AzoresLover (Reply 30):
Not that this had any effect on what happened, just curious...was the plane deiced prior to its taxi? How long would it take in a freezing rain for the buildup of ice on the plane becomes too dangerous to fly? I know that a deiced plane can go a fairly long period of time in snow and still be safe. But ice rain?????

I don't have the charts, but I deiced aircraft last year for a few months... Any airline pilot should be able to further answer your question.

The length of time a de/anti-icing process is good for (holdover time) depends on the temperature and precipitation that is currently falling.

If no precip is falling, Type I deicing fluid can provide a holdover time long enough for a plane to sit and wait for departure.

If frozen precip is falling, then the plane must also have,Type IV anti-icing fluid applied (the green stuff). Depending on the specific type of precip and the intensity, Type IV can last anywhere from an hour or two to just a few minutes. If the holdover time lapses before takeoff, then the plane must be de/anti-iced.

IIRC, the De/anti-icing procedure has no holdover time if freezing rain is falling at moderate or heavy rates.
Commercial / Airline Pilot
 
DualQual
Posts: 709
Joined: Sun Mar 05, 2006 6:10 pm

RE: UA 738 Off Runway

Wed Jan 06, 2016 6:55 am

Quoting flightsimer (Reply 42):

Just as a point of order Type 1 fluid does not provide any holdover time.
There's no known cure for stupid
 
doug_or
Posts: 3237
Joined: Sat Mar 18, 2000 9:55 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 8:54 am

Quoting DualQual (Reply 43):

Just as a point of order Type 1 fluid does not provide any holdover time.

Sure it does. Maybe your carriers opspecs don't allow it, but at least some airlines can go in light snow or active frozen frost.
When in doubt, one B pump off
 
AzoresLover
Posts: 756
Joined: Sun Jun 27, 2004 4:43 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 10:36 am

Thanks, flightsimer. You answered my questions; I appreciate knowing that information.
Those who want to do something will find a way; those who don't will find an excuse.
 
poolkeeper
Posts: 161
Joined: Thu Nov 21, 2013 6:29 pm

RE: UA 738 Off Runway

Wed Jan 06, 2016 10:47 am

Quoting flightsimer (Reply 42):

Thanks for the info

A few years back I had a flight from EWR in very ice conditions.
Only heavies were allowed to take off and we taxied for around 3 hours and the engines were spinning up every 15 min to remove ice.

At the end of the runway we stopped for de-icing and it was done with I think 6 trucks. Immediately after the captain took off. In the air he explained that he needed to be in the air inside 2 minutes after de-icing or it had to be done again.
 
b747400erf
Posts: 3135
Joined: Wed Jun 19, 2013 4:33 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 11:09 am

Quoting DocLightning (Reply 40):

They both have issues. Thunderstorms and mountainous terrain are a risk to aircraft in flight. Snow and ice is a risk to aircraft landing and maneuvering on the ground.

Ice is predictable when you expect it on the ground, if America had to deal with monsoon season there would be a runway excursion a day.
 
B777LRF
Posts: 2583
Joined: Sun Nov 02, 2008 4:23 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 11:58 am

Quoting g500 (Reply 8):
Qantas doesn't have to land on ice-snow covered runways like this one.
Quoting RickNRoll (Reply 35):
And yes, QANTAS does not have to deal with extreme winter conditions nearly as often as other airlines do. In fact, some major airports don't even have CATIII landing set up.

Cat I, II or III has got diddly to due with winter, snow and ice. It's all about visibility. Dubai, Doha, Bahrain, Abu Dhabi and Jeddah are all airports equipped with Cat III runways, and I can assure there's a literal snowballs chance in hell of having snow in any of those places. What they do have, all of them, are dust storms and very thick haze, which are both a serious hazard to visibility. Extreme cold may often be associated with CAVOK so serious, you can see to the edge of the known universe (give or take a parsec). A place with 45C ambient, proximity to an ocean of +30C and a steady sea breeze, well, you've got Cat I, II or II conditions.

Quoting flightsimer (Reply 42):
The length of time a de/anti-icing process is good for (holdover time) depends on the temperature and precipitation that is currently falling.

If no precip is falling, Type I deicing fluid can provide a holdover time long enough for a plane to sit and wait for departure.

If frozen precip is falling, then the plane must also have,Type IV anti-icing fluid applied (the green stuff). Depending on the specific type of precip and the intensity, Type IV can last anywhere from an hour or two to just a few minutes. If the holdover time lapses before takeoff, then the plane must be de/anti-iced.


Allow me please, to don my nerd hat and rabble on a bit about de-/anti-icing ....

1. There are 3 main sources of de/anti-icing procedures: FAA, TC (Transport Canada) and AEA (Association of European Airlines). All issue guidance material, and carriers around the world usually chose to follow one or the other. This makes generalisation in the area a tricky business, as there are subtle differences.

2. Type I is used by everyone, usually for de-icing (the removal of frozen deposits). Type IV is used almost exclusively in North American, most of the rest of the world are using Type II. Both II and IV are used either for anti-icing (the application of a glycol based fluid to prevent build-up of ice), or for a combination of de- and anti-icing. Type II and IV fluids are usually applied in different mixture strengths, particularly if applied in a two-step process; low-mixture for initial de-icing process and high mixture for subsequent anti-icing. HOT will depend on the second step.

3. The FAA, TC and AEA all issues HOT (hold-over time) charts, each with subtle differences. Since each manufacturer have to obtain certification for their product, and each product is slightly different from the others, it gets quite technical, as the HOT will depend on who manufactured the fluid you are using. Most airlines and operators therefore revert to generic HOTs which, although based on the lowest common denominator, make everyones life a lot easier. The FAA guidelines, as well as those from TC and AEA, all provide a HOT for Type I fluids - but only in active frost, e.g. no precipitation: (http://aea.be/component/attachments/attachments.html?id=102&task=download) page 2.

4. Active precipitation also includes frozen fog; it doesn't have to be raining or snowing. Keeping in mind fog is but a cloud hugging the ground, and clouds are 'always' colder than the surrounding air, it's not uncommon that fog in the autumn/spring is also of the frozen kind - all depending on your longitude of course; they do refer to a short few weeks as 'spring' in Dubai, but it's hardly the same concept as in, say, Vermont.

5. Conditions exists whereby the prevailing weather conditions are such, that no HOT can be provided (page 3 on previous link). This is when your airport will come to a grinding halt, and there's nothing you can do except wait for the weather to change. Freezing rain is the 'worst', as anyone who's experienced an 'ice storm' will testify to.

[Edited 2016-01-06 04:00:12]

[Edited 2016-01-06 04:01:21]
Signature. You just read one.
 
maxpower1954
Posts: 1067
Joined: Thu Sep 25, 2008 1:14 am

RE: UA 738 Off Runway

Wed Jan 06, 2016 1:23 pm

Quoting B747400ERF (Reply 47):
Ice is predictable when you expect it on the ground, if America had to deal with monsoon season there would be a runway excursion a day.

Spoken like a true A-net captain. Completely clueless when it comes to real world operations.

Having flown in both SE Asia during monsoon season and NE U.S. winter weather, I'll take the monsoons. I've been an real world captain for decades and NE US weather is the most challenging there is, especially when operating at marginal airports like La Guardia and Washington National.
 
B737900
Posts: 226
Joined: Fri Aug 20, 2010 10:44 pm

RE: UA 738 Off Runway

Wed Jan 06, 2016 3:43 pm

Quoting toltommy (Reply 3):
Extremely icy? Gotta love the media. Wonder what the reported braking action was before landing.

Gotta love these posters that jump to conclusions. Media had nothing to do with it.
Sounds like a Beaver on floats..........we're saved!!

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos