aviationfreak
Posts: 1069
Joined: Sun Nov 09, 2003 9:01 am

Configured For De-icing

Mon Dec 20, 2010 8:36 pm

I work for a handling agent and a few days ago I asked the flight crew of the a/c I've been loading during talkout to configure the a/c for de-icing.
The a/c in question was a 319 and during de-icing I noticed the ailerons were down. I asked the flight crew to retract a few times and configure for de-icing properly. They didn't. A discussion whether this was normal wasn't possible because their english was terrible. At the same time Í was wondering if this could be a normal de-icing configuration for this type. Nobody in my company couldn't say anything sensible about it. I think I should know and they should give me the proper training for this.

Anyways. Can anyone tell me when an a/c exactly is configured for de-icing?
I know all valves and inlets have to be closed and all flaps have to be retracted (which is usually the case during ground-ops) but is there anything I'm missing here.
Can anyone also say anything about that aileron thing.

Thanx in advance.
I love both Airbus and Boeing as much as I love aviation!
 
fr8mech
Posts: 6635
Joined: Mon Sep 26, 2005 9:00 am

RE: Configured For De-icing

Mon Dec 20, 2010 10:27 pm

Ailerons are not 'retracted', they are faired. If both ailerons were down, it is an indication that hydraulics were off the aircraft (likely) or that the weight of the snow and ice on the ailerons was too much for the actuators (unlikely).

Now, I know squat about the A319. They could have a deflected aileron system where the aileron will deflect down a feww degrees when flaps are extended. But normal de-ice configuration (if there is a normal) would typically be flaps up, unless the flaps a contaminated. In which case they would be de-iced, then retracted to de-ice the rest of the aircraft.
When seconds count...the police are minutes away.
 
PGNCS
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Joined: Sun Apr 15, 2007 5:07 am

RE: Configured For De-icing

Mon Dec 20, 2010 11:29 pm

Quoting Aviationfreak (Thread starter):
Anyways. Can anyone tell me when an a/c exactly is configured for de-icing?
I know all valves and inlets have to be closed and all flaps have to be retracted (which is usually the case during ground-ops) but is there anything I'm missing here.
Can anyone also say anything about that aileron thing.

The aircraft is configured for deicing when the flight crew says it is. Some airlines configure with flaps/slats retracted, some do it with the flaps/slats extended to the expected takeoff position. There are other considerations per specific operators and aircraft types (stabilizer setting, etc.) that vary widely.

Quoting fr8mech (Reply 1):
Ailerons are not 'retracted', they are faired. If both ailerons were down, it is an indication that hydraulics were off the aircraft (likely) or that the weight of the snow and ice on the ailerons was too much for the actuators (unlikely).

Now, I know squat about the A319. They could have a deflected aileron system where the aileron will deflect down a feww degrees when flaps are extended. But normal de-ice configuration (if there is a normal) would typically be flaps up, unless the flaps a contaminated. In which case they would be de-iced, then retracted to de-ice the rest of the aircraft.

The A-319 ailerons both droop for additional lift when flaps are extended; it is completely normal.
 
wingscrubber
Posts: 806
Joined: Fri Sep 07, 2001 1:38 am

RE: Configured For De-icing

Tue Dec 21, 2010 1:47 am

Aileron position shouldn't matter, the engine inlets, leading edge and upper wing surface are the most important areas to de-ice. In the cockpit all that's required is to switch the bleed air anti ice on, then they're good to go.

If those ailerons are still drooping when the aircraft lines up for take-off though, that is something to worry about! Except on some older airplanes with trimtabs instead of hydraulics.

Were the engines running at the time? If so, you could have just reminded them to 'power up hydraulics', if the engines weren't running then those ailerons will stay put until startup. You were right to question it though Avfreak, never stay quiet if you think something is amiss on an aircraft!
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PGNCS
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Joined: Sun Apr 15, 2007 5:07 am

RE: Configured For De-icing

Tue Dec 21, 2010 1:52 am

Quoting Wingscrubber (Reply 3):
If those ailerons are still drooping when the aircraft lines up for take-off though, that is something to worry about!

Sorry, no...

Quoting PGNCS (Reply 2):
The A-319 ailerons both droop for additional lift when flaps are extended; it is completely normal.
 
pilotpip
Posts: 2820
Joined: Fri Sep 19, 2003 3:26 pm

RE: Configured For De-icing

Tue Dec 21, 2010 4:21 am

Configuration will also vary by airline.

In addition to the bleed set up as mentioned, the other important items are trim settings and flap settings. At my airline we turn the bleeds off, flaps are up and the stabilizer trim is full nose-down. The APU and engines can be running in any set up. I will advise the deice crew of what engines are running so they know.
DMI
 
cvg2lga
Posts: 426
Joined: Fri Feb 25, 2005 11:48 am

RE: Configured For De-icing

Wed Dec 22, 2010 2:52 am

Just be careful not to drown out the APU. Crews get pretty upset about that sometimes. Most times they don't and sometimes it isn't even the sprayer's fault, can really depend on the wind. Good luck, keep a sharp eye out and a safe distance and like somebody said above, don't hold back if you think it could affect the safety of those onboard.

Oh and I hope you're lucky enough not to get stuck tactiling if your pads perform that position. It was always the shortest straw to me lol.

Tchau

DA-
They don't call em' emergencies anymore. They call em' Patronies.
 
Tristarsteve
Posts: 3364
Joined: Tue Nov 22, 2005 11:04 pm

RE: Configured For De-icing

Wed Dec 22, 2010 5:17 am

Depends on the aircraft.
On a A319, and other Airbusses, to configure for deicing you push in the Ditching button. This closes the bleed valves and the outflow valves and other valves in the air system. The ailerons will usually be down as the hydraulics are off. The flaps will usually be up and the stab neutral.
On a B737 you close the APU bleed valve, and position the stab fully nose up. This is to stop deicing fluid filling up the balance area on the elevators.

It is normal to deice with flaps up, but if the crew leave them down on arrival for inspection, and it is snowing, then sometimes they must be left where they are. This increases the deicing time considerably.
When the aircraft is deiced with the flaps up, it is normal to leave them up until you enter the runway.

But all airlines have their own procedures. Just ask the crew if they are ready for deicing. I have a lot of discussions with crews from warm countries who don't deice very often, and are not familiar with the procedure. Biggest problem is when they insist on slowly following their procedure manual after deicing, and then complaining that they are running out of hold over time.
 
Barnesy2006
Posts: 46
Joined: Sun Feb 04, 2007 7:27 am

RE: Configured For De-icing

Wed Dec 22, 2010 10:19 pm

Quoting Tristarsteve (Reply 7):

The stabs should be positioned fuelled nose down on a 737.
 
wingscrubber
Posts: 806
Joined: Fri Sep 07, 2001 1:38 am

RE: Configured For De-icing

Sun Dec 26, 2010 3:19 am

Quoting PGNCS (Reply 4):
Sorry, no...

Fair enough, I stand corrected... I had thought that aileron droop on the A320 family was an indication that hydraulics were powered down. If they are synced with the flaps then seeing them down on takeoff would be normal too I suppose.

Quoting Tristarsteve (Reply 7):

Depends on the aircraft.
On a A319, and other Airbusses, to configure for deicing you push in the Ditching button.

Cool, did not know that!
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Tristarsteve
Posts: 3364
Joined: Tue Nov 22, 2005 11:04 pm

RE: Configured For De-icing

Sun Dec 26, 2010 11:20 am

Quoting Barnesy2006 (Reply 8):
The stabs should be positioned fuelled nose down on a 737.

No, the stab is positioned STAB Nose UP. (Or aircraft nose down if you prefer).

The B737 has aerodynamic balance panels in the elevator system. If you don't do this deice fluid fills them up.
 
sandrozrh
Posts: 2420
Joined: Sun Feb 04, 2007 12:19 am

RE: Configured For De-icing

Sun Dec 26, 2010 2:56 pm

Quoting Tristarsteve (Reply 7):
On a A319, and other Airbusses, to configure for deicing you push in the Ditching button. This closes the bleed valves and the outflow valves and other valves in the air system

Correct, Ditching on and engine bleed 1&2 off.

Quoting Tristarsteve (Reply 7):
The ailerons will usually be down as the hydraulics are off. The flaps will usually be up and the stab neutral.

Correct. However horizontal stab trim is never neutral, usually it will be what it was whenever the aircraft was parked up from the previous flight and it will be set to the applicable ZFW CG for the next flight during the after engine start checklist. Vertical stab trim will be set to zero during the after engine start checklist.

Don't worry though, I'm nitpicking here  
 
Tristarsteve
Posts: 3364
Joined: Tue Nov 22, 2005 11:04 pm

RE: Configured For De-icing

Sun Dec 26, 2010 5:56 pm

Quoting sandroZRH (Reply 11):
However horizontal stab trim is never neutral, usually it will be what it was whenever the aircraft was parked up from the previous flight

But if you are nit picking, the stab trim retrims to zero all by itself after landing.
If you see stab trim not at zero on the ground, something is wrong.
 
sandrozrh
Posts: 2420
Joined: Sun Feb 04, 2007 12:19 am

RE: Configured For De-icing

Mon Dec 27, 2010 12:05 am

Quoting Tristarsteve (Reply 12):
But if you are nit picking, the stab trim retrims to zero all by itself after landing.
If you see stab trim not at zero on the ground, something is wrong.


Yes, you're right. I was talking about somethign entirely different, it all started when i misread the OP's post in the first place.

That's what happens when you're posting on airliners before having the first cup of coffee of the day  

Consider my post as irrelevant.

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