awthompson From United Kingdom, joined May 2005, 355 posts, RR: 0 Posted (5 months 1 week 3 days 9 hours ago) and read 5076 times:
As a Private Pilot I am aware of the importance of keeping aerodynamic surfaces clear of ice/snow/frost however I would genuinely be interested in comments on the following:
Last night I took BA1426, G-MIDT, from LHR to BHD. Senior First Officer, after doing outside inspection came down cabin and visually sighted wings from passenger windows. He concluded that wings and tailplane had some frost and called for de-icing before departure. I noted that really there was very little frost at all. There is nothing wrong with that, excellent airmanship in fact and what I would expect from BAW. Captain also informed passengers exactly what was going on which was great.
In contrast, however, a couple of weeks ago I was on a diverted flight into RIX, also an Airbus A320 but with a different major airline. During a lengthy late night stop before departing again, the upper wing surface developed a fairly thick layer of frost. I took a photograph of same. No-one looked at upper wing surface, either from the outside or the inside, except me of course! I was a little perturbed when we taxied out without any de-icing and proceeded to take off. I may say that the take off was quite spritely and the frost covering made little noticeable difference to the rate of climb. Albeit we had a relatively light load.
FlyDeltaJets From United States of America, joined Feb 2006, 1625 posts, RR: 3 Reply 1, posted (5 months 1 week 3 days ago) and read 4660 times:
There is definatly a varience with even different crews in the same airline. There have been times that in the middle of May we would have to crank the de-icing trucks to de-ice CX because of frost on the wings from the wings being cold from the long flight to JFK. There have also been times that during heavy snowfall certain SU crews will advise "Negative de-icing ready for taxi."
Tristarsteve From Sweden, joined Nov 2005, 3693 posts, RR: 34 Reply 3, posted (5 months 1 week 2 days 21 hours ago) and read 4582 times:
Quoting FlyDeltaJets (Reply 1): There have also been times that during heavy snowfall certain SU crews will advise "Negative de-icing ready for taxi."
We had a really bad day at ARN last week., heavy snow, very windy, icy runway low braking action..
From 0800 to about 1400 only about 10 aircraft departed, 6 of them to Russia.
It is the attitude to risk that is important. The rules are the same. Wings must be clean (with a few exceptions, like above the MLG, and smooth under the wing). A major airline will abide by this. Others do not. They are saving money. They will usually get away with it, be happy, and do it again. On a A320 on a long runway with a light load, even frost on the wings will be no problem. But, who decides how much is OK? So we say non at all, just to be on the safe side. Because next time the frost will be uneven, the runway will be short, and the plane will be at MTOW, and it will not be OK.
Read the accident report about the Air Florida B737-200 that went into the Potomac.
It says that the aircraft would have cleared the bridge if the engines had been at take off power, even without deicing.
B777LRF From Luxembourg, joined Nov 2008, 1006 posts, RR: 3 Reply 4, posted (5 months 1 week 2 days 13 hours ago) and read 4458 times:
Airlines should operate to the "clean wing concept", which precludes the presence of any snow, ice or frost (except for a very thin layer of hoar frost) on any aerodynamic surface. Some airlines take it a bit further by not even allowing a thin layer of hoar frost, and as a safety manager that's the approach I advocate.
The airlines that don't follow the clean wing concept, well, they are probably the same ones who'll have you believe that "safety is our no. 1 priority", while failing to add "unless we find it's too expensive".
History is littered with examples of what might happen if you have a relaxed attitude towards anti-icing.
From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 5, posted (5 months 1 week 2 days 10 hours ago) and read 4376 times:
Quoting B777LRF (Reply 4): Airlines should operate to the "clean wing concept", which precludes the presence of any snow, ice or frost (except for a very thin layer of hoar frost) on any aerodynamic surface.
There is usually an exception to that for frost condensed out by cold fuel...without atmospheric precipitation, condensation frost like that is no threat and almost impossible to get rid of for any long period without heating the fuel.
awthompson From United Kingdom, joined May 2005, 355 posts, RR: 0 Reply 6, posted (5 months 1 week 2 days 9 hours ago) and read 4351 times:
Here is my photo. Can someone who is familiar with the position of wing fuel tanks on an A320 confirm if this is fuel tank surface frost, many thanks for comments thus far.
longhauler From Canada, joined Mar 2004, 4281 posts, RR: 36 Reply 7, posted (5 months 1 week 2 days 8 hours ago) and read 4319 times:
Quoting tdscanuck (Reply 5): There is usually an exception to that for frost condensed out by cold fuel...without atmospheric precipitation, condensation frost like that is no threat and almost impossible to get rid of for any long period without heating the fuel.
That is only allowed on the underside of the wing.
If it does occur on the top of the wing, and under some conditions it can, then it must be removed using de-icing methods. It is not normally an issue in humid climates where often it is also warm enough to melt quickly, but I have seen it where the temp is around 15C and we had to de-ice.
Regardless of the cause ... fuel included ... that would not be allowed in Canada. The only frost allowed on the upper surface of the wing is on the spoiler panels, and even still, under certain conditions.
Never gonna grow up, never gonna slow down .... Barefoot Blue Jean Night
YYZatcboy From Canada, joined Apr 2005, 809 posts, RR: 0 Reply 8, posted (5 months 1 week 2 days 6 hours ago) and read 4285 times:
Quoting longhauler (Reply 7): If it does occur on the top of the wing, and under some conditions it can, then it must be removed using de-icing methods.
Not so. The 737NG has an exemption for fuel frost on the top of the wing. The area is outlined in black on the top of the wing.
I was quoting right out of the A320 AOM, the aircraft on which the OP flew.
"A coating of frost up to 1/8" thick is permitted on wing lower surfaces ONLY (their capitalization, not mine ), in the area cold soaked by fuel, between forward and aft spars".
I understand that other aircraft types allow different levels of wing icing. Looking at the picture posted, it does appear to be caused by cold fuel, as the frost is not on the slats, nor aft of the rear spar. Had this occurred in Canada it would likely have been deiced.
Never gonna grow up, never gonna slow down .... Barefoot Blue Jean Night
YYZatcboy From Canada, joined Apr 2005, 809 posts, RR: 0 Reply 10, posted (5 months 1 week 2 days 5 hours ago) and read 4234 times:
Yes my mistake. I read that as saying that fuel frost on the top of the wings on any aircraft was not allowed in Canada, as opposed to specificaly the airbus. Apologies.
longhauler From Canada, joined Mar 2004, 4281 posts, RR: 36 Reply 11, posted (5 months 1 week 2 days 3 hours ago) and read 4198 times:
Quoting YYZatcboy (Reply 10): Yes my mistake. I read that as saying that fuel frost on the top of the wings on any aircraft was not allowed in Canada, as opposed to specificaly the airbus. Apologies.
You did raise an interesting point though. Under some icing conditions the B737NG is less restricted than narrow-body Airbuses. Not a lot of people are aware of that.
I have had passengers ask me why there are so many more Air Canada aircraft in the de-icing bay than Westjet. One has to be very careful of the response, as to be derogatory brings down the whole industry! But if they ask me, I can imagine the same thing happens with them ... but worse ... passengers are asking them why Air Canada is de-icing but they are not!
Never gonna grow up, never gonna slow down .... Barefoot Blue Jean Night
YYZatcboy From Canada, joined Apr 2005, 809 posts, RR: 0 Reply 12, posted (5 months 1 week 2 days 3 hours ago) and read 4183 times:
Out of my own curiousity, are the widebody Boeing or Airbus Widebodies more or less restrictive than the narrobodies. For example are there upper wing fuel frost restrictions on the Airbus widebodies but not the narrow bodies and conversely is there a restriction on the boeing widebodies as opposed to the 737? My only experience has been with NG's so I'd be interested in finding out about the widebodies.
B777LRF From Luxembourg, joined Nov 2008, 1006 posts, RR: 3 Reply 14, posted (5 months 1 week 1 day 19 hours ago) and read 4083 times:
Well, if the Boeing books allow frost on the upper surface of B737NG that's their position. It does not necessarily follow that any airline buying the product should not not impose more strict procedures. Keep in mind that manuals are quite often listing minimum requirements; it's up the owner to gauge whether they're fine with that, or if more stringent measures are called for.
Besides, it's my experience with both Boeing and Airbus that they're good, very good, at building aeroplanes. Operating them though is a different kettle of fish, and I'm not always convinced they've got their heads on right when it comes to the operational side of things.
From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
CosmicCruiser From United States of America, joined Feb 2005, 2212 posts, RR: 16 Reply 15, posted (5 months 1 week 1 day 15 hours ago) and read 4023 times:
Quoting longhauler (Reply 9): "A coating of frost up to 1/8" thick is permitted on wing lower surfaces ONLY (their capitalization, not mine ), in the area cold soaked by fuel, between forward and aft spars".
That's pretty much our policy regardless of aircraft type. (and we do Airbus)
"§ 91.527 Operating in icing conditions. (a) No pilot may take off an airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface; to a powerplant installation; or to an airspeed, altimeter, rate of climb, or flight attitude instrument system or wing, except that takeoffs may be made with frost under the wing in the area of the fuel tanks if authorized by the FAA.
(b) No pilot may fly under IFR into known or forecast light or moderate icing conditions, or under VFR into known light or moderate icing conditions, unless—
(1) The aircraft has functioning deicing or anti-icing equipment protecting each rotor blade, propeller, windshield, wing, stabilizing or control surface, and each airspeed, altimeter, rate of climb, or flight attitude instrument system;
(2) The airplane has ice protection provisions that meet section 34 of Special Federal Aviation Regulation No. 23; or
(3) The airplane meets transport category airplane type certification provisions, including the requirements for certification for flight in icing conditions.
(c) Except for an airplane that has ice protection provisions that meet the requirements in section 34 of Special Federal Aviation Regulation No. 23, or those for transport category airplane type certification, no pilot may fly an airplane into known or forecast severe icing conditions.
(d) If current weather reports and briefing information relied upon by the pilot in command indicate that the forecast icing conditions that would otherwise prohibit the flight will not be encountered during the flight because of changed weather conditions since the forecast, the restrictions in paragraphs (b) and (c) of this section based on forecast conditions do not apply.
[Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as amended by Amdt. 91-310, 74 FR 62696, Dec. 1, 2009]"
MD11Engineer From Germany, joined Oct 2003, 13337 posts, RR: 64 Reply 17, posted (5 months 1 week 1 day 14 hours ago) and read 3999 times:
Quoting YYZatcboy (Reply 8): Quoting longhauler (Reply 7):
If it does occur on the top of the wing, and under some conditions it can, then it must be removed using de-icing methods.
Not so. The 737NG has an exemption for fuel frost on the top of the wing. The area is outlined in black on the top of the wing.
That depends on the relevant aviation authority. E.g. the Irish Aviation Authority does not allow any ice on top of the wing, so their interpretation is stricter than the Boeing one and the respective chapter, which permits frost in certain areas on top of the wing, in the Boeing maintenance manual has to be disregarded for Irish registered B737NG.
longhauler From Canada, joined Mar 2004, 4281 posts, RR: 36 Reply 18, posted (5 months 1 week 1 day 13 hours ago) and read 3981 times:
Quoting YYZatcboy (Reply 8): Not so. The 737NG has an exemption for fuel frost on the top of the wing.
Back to this again.
I just read through the CARs section on ground icing, and I can find no exemption for any aircraft type. It states the same thing as our Flight Ops Manual, in that the only exception to the requirement for a clean wing is frost on the underside of the wing in the area of fuel storage.
I think what a lot of people on here are posting may be correct in Canada as well. While the manufacturer may deem it safe, it is overruled by the governing country's air regs.
But it does answer a question of mine. In line for take-off in ground icing conditions, all of AC's aircraft have green wings (Type IV) and WS aircraft have orange wings (Type I). That would satisfy the CARs requirement. (When passengers ask why the difference in colour, I just tell them its to match our superior paint scheme ... )
Never gonna grow up, never gonna slow down .... Barefoot Blue Jean Night
yeelep From United States of America, joined Apr 2011, 526 posts, RR: 0 Reply 20, posted (5 months 1 week 1 day 11 hours ago) and read 3936 times:
No, that is the CSFF (cold soaked fuel frost) boundary outline that was applied by Boeing SB737-11-1125. "Black lines are being added to the wing upper surface that defines the permissible area for CSFF. These lines were incorporated in production on airplane line number 1538 as a standard feature. This airplane was delivered in July 2004."
flyingturtle From Switzerland, joined Oct 2011, 1283 posts, RR: 2 Reply 21, posted (5 months 1 week 1 day 11 hours ago) and read 3928 times:
Quoting CALTECH (Reply 16): "§ 91.527 Operating in icing conditions.
(a) No pilot may take off an airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface;
Adhering? This means, as long as the snow isn't frozen to the surface, the A/C is good to go?
David
Even a letdown, if it is thoroughly and final, is a step forward.
To answer your question, it depends on the individual airlines de-ice program. At my airline the answer is yes, within very narrow guidelines/conditions:
Under the following conditions, contamination on critical surfaces can be determined to be
“Non-Adhering”:
• Ambient temperatures generally below -10 to -15°C or colder
• Snowfall/Ice Crystals are dry and light
• Any contamination that will blow about on clean, dry, cold aircraft surfaces under light
wind conditions or while taxiing
• Verify the surface under the snow is cold, clean, and dry
Under these conditions, dry snow will swirl as it blows across the wings, making it evident
the snow is not adhering. But if snow has accumulated on the surface of the wings, it has to
be removed prior to takeoff. It cannot be assumed that accumulation of snow will blow off
during takeoff.
NOTE: Refueling with fuel warmer than the wing skin temperature may create a
condition that previously non-adhering contaminants may adhere to the wing
surfaces
B777LRF From Luxembourg, joined Nov 2008, 1006 posts, RR: 3 Reply 24, posted (5 months 1 week 1 day 8 hours ago) and read 3864 times:
Quoting CALTECH (Reply 16): No pilot may take off an airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface; to a powerplant installation; or to an airspeed, altimeter, rate of climb, or flight attitude instrument system or wing, except that takeoffs may be made with frost under the wing in the area of the fuel tanks if authorized by the FAA.
That's the exact wording in our manual, if you delete the words after "fuel tanks", and we're not a FAA regulated carrier. The last time this point was raised at a safety meeting was around 5 years ago, when someone - correctly it must be added - mentioned that the wording we used was derived from the FAA, and questioned why we, as a Belgium CAA regulated airline, were following those rules. I don't recall the exact answer, but it was something along the lines of "it's the best wording we know of and satisfies our requirement for safety first".
There's very good saying in safety circles: If you think safety is expensive, try an accident.
From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
25 KBGRbillT: Does anyone recall of an airliner crashing and the determination was that frost on the upper wing skin or control surfaces was the sole cause for this
26 Starlionblue: SK 751. http://en.wikipedia.org/wiki/Scandinavian_Airlines_Flight_751
27 Fabo: Kind of. Actuall reason would be dual engine flameout would it not? AFAIK the airplane would have flown on if it had thrust. I would much sooner cite
28 Starlionblue: Agreed. Then again it does illustrate that icing can be insidious in many ways.
29 faro: On the -hopefully very distant- day that an operator does not get away with it, what is the airport authority's responsibility? If at present airport
30 Starlionblue: My theory is that the airport authority typically will not know enough about aircraft operations to make these kinds of decisions. Knowing what each
31 Fabo: They defintely do around here. When the snowfall is intensive and it is impossible to maintain clean runway for even couple movements, the airport wi
32 tdscanuck: No. The PIC is responsible for safe operation of the aircraft, including de-icing. Because the airport is completely unqualified (relative to the fli
33 airbuster: [quote=awthompson,reply=6][/] So, You are now in the same situation but know that that frost should be removed. What do you do. You're pushed back tax
34 KBGRbillT: Both of these crashes were due to ICE on the wings. My post asked if any crash could be attributed to FROST only on the wings. I've never heard of an
35 Tristarsteve: Yes in the SK accident the plane flew OK until the engines stopped producing thrust due to ice ingestion. I do not think you will find an airliner ac
36 CALTECH: Well, was talking about the A-320 photo posted, not a 737. Does the A-320 have a CSFF line painted on it ?
37 intsim: I was the Certified Deice Instructor at our remote station when I worked at NWA. I would add that in our case the ramp crew was also responsible and
38 yeelep: I'm sorry for the confusion, but you were replying to post eight which linked and commented on a westjet 737.
39 CALTECH: Yes you're right. I meant the A-320 in reply 6. Sorry about that, my fault.
40 faro: As a Certified Deice Instructor do you report to the airline or to the airport authority? Faro
41 CALTECH: Some further info, at United the 737s do not have a CSFF line. They just have the 'No Step' boundary line, which the CSFF line seems to follow. The t
43 CALTECH: Is part of the CSFF line that lighter gray line running chordwise in the photo on the right ? Just in front of the outbd flap fairing ? I must have l
45 intsim: The airline. This was all part of the NWA training and record keeping. We had a log that contained the detailed information, temp, types of fluid use
46 CALTECH: That is a good view. Looks to be part of the 'No Step' boundary, just smaller, which is also the outline of most of the wing tank too, just not quite
47 yeelep: It may be that when the planes are repainted the CSFF lines are being deleted. They aren't a FAA required marking and since the FAA doesn't allow CSF
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