PDA

View Full Version : Decision on amount of Ice


601
1st Jul 2013, 23:53
Latest bit of legislation by Instrument
This instrument permits an aircraft with a maximum take-off weight of more than 5 700 kg that is engaged in regular public transport operations to take off with residual traces of snow, frost and ice. The exemption is subject to conditions directed by CASA in the interest of safety, including that the pilot in command must ensure that appropriate procedures have been used and be satisfied that any residual traces of snow, frost or ice will not affect the performance of the aircraft.

How does a PIC be satisfied "that any residual traces of snow, frost or ice will not affect the performance of the aircraft" on aircraft like a Dash 8?

OneDotLow
2nd Jul 2013, 00:13
I'm not sure about the Dash 8, but the B767 flight manual has guidance for the pilot :

Takeoff with light coatings of frost, up to 1/8in (3mm) in thickness on
lower wing surfaces due to cold fuel is permissible; however, all
leading edge devices, all control surfaces, and upper wing surfaces
must be free of snow or ice.
Thin hoarfrost is acceptable on the upper surface of the fuselage
provided all vents and ports are clear. Thin hoarfrost is a uniform
white deposit of fine crystalline texture, which usually occurs on
exposed surfaces on a cold and cloudless night, and which is thin
enough to distinguish surface features underneath, such as paint lines,
markings or lettering.


I imagine that the Dash 8 flit manual would have a similar statement.

waren9
2nd Jul 2013, 01:12
320 and 330 manuals specify similar.

if there is no direction from the manufacturer, and that direction has not had a tick from the regulator then dont do it.

Cessna Capt
2nd Jul 2013, 02:56
The B737 has a similar statement in its manual allowing you to operate with a thin layer of ice/frost within an outlined area marked on the wing.

However, the company policy where I'm employed and I suspect is the same at many other operators is a 'Clean Wing Policy'. No build up allowed despite being allowed to do so under the regs/manufacture's guidance.

dartman2
2nd Jul 2013, 04:08
A seemingly meaningless document. The restrictions in the AFM are what you are required to follow. The only possible use for this instrument would be for an aircraft that does not have guidance in the AFM. All Boeing and Airbus products do. If your aircraft does not have a similar statement I would follow the advice of the major manufactures as outlined in the posts above and seek clarification from CASA that this is acceptable in terms of the instrument.

Toppie
2nd Jul 2013, 06:42
The CASA reg formerly required an aircraft to be free of snow/frost/ice. Most jet operators will describe the formation of a very thin layer of ice on the underside of wings where the skin meets the fuel tanks. The cold fuel after a long cruise causes this layer of frost to form as you descend into more humid air. As correctly described above, most AFM/FCOMs permit a small layer of ice in the vicinity of the fuel tanks, to allow dispatch before the ice fully melts. The CASA change allows a more sensible approach and removes the requirement for a deice to legally dispatch the jet in the event of short turns.

Your Steak Is Ready
2nd Jul 2013, 06:52
The method for determining if there is excessive ice on a Dash 8 is to observe the ground spoilers in the deployed position. If there is discolouration of the surfaces it is dreamed that there is too much ice on the airframe.

I will have my steak medium Rudd.

Sunfish
2nd Jul 2013, 10:51
Cold fuel and ice on undersides is well known. CASA has just given permission to attempt takeoff with ice elsewhere as long as you absolve CASA. Leadership? Not.

Capt Fathom
2nd Jul 2013, 11:49
CASA have not given that permission Sunfish. Commercial operators will be bound by the directions in their Ops Manuals!

So nothing has changed in practical terms. Unless you are a gambler?

004wercras
2nd Jul 2013, 12:07
The Ops Manual for most operators won't change. If the companies OM complies with the legislation and the AFM, then what is the issue? Plus at some point the procedures contained within the OM would have been 'accepted' by the ninnies at Fort Fumble.
Perhaps I have missed something here, but generally speaking it will be business as usual? The only thing I see changing is that CAsA has massaged some of the wording to ensure accountability is placed in the operators crotch, and if something does go horribly wrong CAsA will be a considerable distance away from the blame game? "Not me officer, I wasn't there, I was out of town, in Montreal".

Happy to stand corrected if I have drifted in my understanding? Fort Fumbles golden pen men have a fine knack of changing a couple of words (sometimes a lot of words) and leaving you completely bamboozled.

Sunfish
2nd Jul 2013, 12:13
Agree with 004. What is the point Of the rule apart from insulating CASA from any risk?

How does this advance the cause of air safety?

Where is the value add?

old rope
3rd Jul 2013, 09:17
Something to do with A330 outer tank ice...?

I believe Airbus was doing some work on this in recent years

TURIN
3rd Jul 2013, 09:41
The B737 has a similar statement in its manual allowing you to operate with a thin layer of ice/frost within an outlined area marked on the wing.

737NG has the black markings. Boeing say its ok with Ice the CAA/FAA say clean wing. Unless something has changed recently.


Something to do with A330 outer tank ice...?

I believe Airbus was doing some work on this in recent years

No need, just open the fuel transfer valves before refuelling, the cold fuel drains into the main tanks and the new warm fuel fills the outer tank, defrosting the wing. As long as you remember to close the transfer valves or the fuel won't go on. :O

Assuming the fuel from the bowser is above 0 deg of course. :oh:

kaikohe76
4th Jul 2013, 09:42
Call me over cautious if you like. For me, the only safe amount of ice, is none at all! I would feel less than happy, if an aircraft on which I was a pax, began flight with ice on it.

OneDotLow
4th Jul 2013, 10:57
Kaikohe,

I'm all for being cautious, particularly where the manufacturer provides no guidance, but in this case I'm happy to proceed where the contamination is as described in the flight manual as being safe to proceed. The reality is that if you fly regularly, you will have almost certainly paxed on an aircraft with some level of acceptable wing contamination due to ice.

Greedy
4th Jul 2013, 23:12
It really does not matter what "instruments" ,FCOMS, CAR'S etc have written. It all boils down to what CA(s)A decide to do in the circumstances.
It is not so long ago that CA(s)A supported a Chief Pilot who stated in court that frost could be removed with a bucket and hot water only. Fast taxi would then blow frost off . This on an aircraft of similar size to a dash 8.

The writing does not matter. It is the corrupt application of rules and procedures by CA(s)A and other bullies to suit their own agendas or protect their own positions.

Greedy

coco-nuts
9th Jul 2013, 10:28
Something I learnt from a Canadian (they know a little about ice), if in doubt, (737 in this case) open your window and run your hand along the topside of your cockpit. If you can feel the ice, DON'T GO! Saved my bacon!

Aus380
15th Jul 2013, 11:42
Usually depends on passenger load and if there is a separate bar service. Also if the bar carts are loaded chilled we usually go through less ice than if they come on warm.

Ned Gerblansky
16th Jul 2013, 07:50
I seem to remember years ago when the company for which I worked lost a lot of young, talented pilots to Cathay - the question was asked of them all at interview "When would you attempt a take-off with ice on your wings?"

Never is the correct answer. If you're not in Cathay the answer is :
F%$CKING NEVER! I remember once at Glen Innes, 0430 and minus 11 degrees celcius. Aircraft was frosted over and cold-soaked, anti-icing hadn't been arranged yet (to save costs) and operations advised me to put a hose on it and wash the ice off.

I invited the gentleman on the other end of the 'phone to combine copulation and departure. One life - that's all you've got. Remember that - it's one of life's memory items.

Cheers,

Ned