Pre-takeoff Contamination Check

[ricfly744]

Hello all,

In my book, this check must be done from outside the aircraft (in very special cases, may be from inside), when HOT expired or WX conditions worsening limiting expected HOT.
My question: Have you ever seen specific personnel placed near RWY holding points, able to make this check and report findings to pilots?
In case I need to request a check like this, just before TO, I cannot imagine in practice how it will work. Who will come or already be strategically placed and equipped to attend, inspect and communicate the result.

About the Pre-takeoff Contamination Check:
Has it been requested by you?
How did it go?

Happy Winter Ops!

[JeroenC]

Our book says from inside cabin. If unhappy with result or unable to determine: back to base.

[Skyjob]

Ricfly744 - AMS has actually got several deicing aprons located strategically throughout the airport. Subject to the operational requirements of crew they can get deiced right near the threshold of several runways.

The crew operating the equipment near the runway after deicing will give you the information over VHF and could facilitate this check. Realistically though, there is little to no logistical option to have someone visually inspect from outside, so the only option you have is to look out the window, an overwing one would be best placed.

JeroenC is right though, don't like it (the HOT), don't fly it. It's not worth becoming a statistic.

[nitpicker330]

Read the Transport Canada guide page 11.1.7

TP 14052 - Guidelines for Aircraft Ground - Icing Operations - Transport Canada (http://www.tc.gc.ca/eng/civilaviation/publications/tp14052-menu-314.htm)

My mob follow them with good reason!! ( they ARE the experts )

Inspection Immediately Prior to Takeoff

General An inspection is not required until the lower (more limiting) HOT has been exceeded, provided conditions do not exceed those represented by the table. When making this assessment, the impact of other factors (e.g. jet blast) shall be taken into account. If there is doubt surrounding the conditions associated with using the lowest time as the decision making criteria, an inspection prior to takeoff would be prudent.

Pre Takeoff Contamination Inspection A Pre-takeoff Contamination Inspection shall be completed if the elapsed time is within the range of time given in the HOT table for the conditions present. The check will consist of a visual inspection performed from the aircraft cabin of the upper wing surfaces within 5 minutes prior to the commencement of takeoff. If evidence of ice, snow or frost accretion is observed, or any doubt exists over the condition of the critical surfaces, the aircraft should return for additional de/anti-icing.

Pre Takeoff Contamination Check Should the higher (less limiting) time in the HOT table be exceeded, the only option available to permit takeoff is a Pre Takeoff Contamination Check, which shall be completed externally by authorized ground staff. If it is not possible to conduct this check, or it is not possible to takeoff within 5 minutes of conducting the check, the aircraft must return for de/anti-icing

[Field In Sight]

20kts before V1 ask the cabin crew what they can see on the wing.

deicing the russian way.flv - YouTube

[ricfly744]

Good one Field, thanks for the post.
I have seen this tube in the past and wanted to find it again.....very interesting, and we can say that the Russians are one of the most experienced winter operators in the market, and they are not crazy. They must know by experience that in cases of only dry snow, like this case, using an improved climb type v speeds is safe. I certainly respect their experience, but if sitting in that flight, I would call CC not to allow TO before I heard from the PIC what he would do with speeds and his considerations. I once, as PAX in an Air China B767 flight, out of PVG saw significant frost over wings and noted that they would go like that. I called the CC and asked her to inform the PIC, she did, he sent the FO to check, and they de-iced.

[nitpicker330]

You are kidding.........right?

[ricfly744]

Watching the clip a few more times, we can see that even after airborne, a significant amount of contamination remained. Not safe. Let's say, wing temperatures soon become different if there is shadow in one and sun exposure on other, it may get worse.
As I mentioned before, they are experienced, but now I agree that they may be crazy.

How about the Pre takeoff Contamination Check, From outside the cabin?

Have you ever requested it just prior to GO?
Was there anybody to respond and perform it?
Do some airports have special vehicles with platform to inspect the wings and people ready to attend?

The point is: all books mention this procedure, but in reality, does it ever happen?

Why write and instruct crews to conduct a procedure that is unrealistic, and if requested, may make a fool out of the captain, that would be only following his book.

- Tower, can you send some one here to check my wings? Or
- Ice man can you perform the PTCC here in taxiway X?

Joke or just following procedures?

[nitpicker330]

Nope I've never had to have one done, if I did it would have to be performed by a qualified person.

As far as I know there isn't anyone positioned to the threshold to do this anyway.

So if the longer HOT time expires and precipitation ( snow etc ) is falling then it's back to the de-icing we go.........( or to the hotel !! )

[mototopo]

..And don't forget, even with no precipitation after HOT expired the fluid is likely to freeze, so it becomes a contaminant itself.. After an unsuccesful check, no way we go back..

[JammedStab]

Have heard of it being done in Anchorage. I would assume that there must be some sort setup between ATC and a particular company to do this or some sort of general procedure for certain companies to get a vehicle out to a taxiway near a runway.

That being said, having flown in cold areas for many years in the past and reading accident reports, I have had a bit of experience with frost. For aircraft such as the old DC-9, F-28 and CRJ-200 types with no slats, it is best to be very paranoid about wing contamination. These appear to be unforgiving small amounts of it.

One has to conclude that over the years many jet takeoffs have been done with contaminated wings of varying degrees yet virtually all the accidents have been with the so-called hard wing aircraft with no slats.

So what to do if you discover that the little bit of frost that you had on the wings prior to departure is still there because you forgot to de-ice and you remember this just as you passed V1. Reject perhaps?

You are the PIC and that is why you get paid the big bucks but I would suggest considering a deliberately higher speed be used for rotation and that it be done at a slower rate to a lower pitch attitude.

Also be careful when it is just above freezing and you have the drops of water on the wings. It is quite possible that they have frozen as the temperature dropped so de-icing liquid water might be a good idea in some cases.

[BARKINGMAD]

Do I get the awful suspicion that post 9/11 we pilots are afraid of going back into the cabin to assess the condition of the 'frame at any time we so consider necessary?

I appreciate the OP referred to an external inspection by (hopefully qualified) observers, but ultimately the operating captain is responsible etc etc.

After 3 winters operating from KEF as a base, alas I would trust NOBODY outside the aircraft to assure me of a lack of contamination!

Sad, but true, so stuff Al Quaeda and the rest, get outa yer seat and get back there at the o'wings and LOOK!

That's what we're paid to do, innit?!

[KBPsen]

Do I get the awful suspicion... I don't know. Do you?

I appreciate the OP referred to an external inspection by (hopefully qualified) observersWhat makes you more qualified? What training have you received that makes you qualified to determine whether deicing or a new application of deicing is required? Or is it just assumed that you know? How does your possible training compare to the person the ground?

[TURIN]

Well, in the company I work for its the same. No guarantee that away from base you will get inspected by a colleague though.

[main_dog]

I appreciate the OP referred to an external inspection by (hopefully qualified) observers, but ultimately the operating captain is responsible etc etc.

True, but especially if you operate a widebody such as a 747, it is very hard to properly see the state of the wing from inside the aircraft, especially at night. Clear ice that may have formed will be all but invisible, indeed during the pre-flight walk-around if I have any doubts at all I get an engineer to request a "cherry-picker" (high-lift truck) and physically touch the wing, the only way to really make sure what you are seeing is water and not clear ice. So a quick glance at the wing from the inside by a crewmember on a dark snowy night does not guarantee much.

In my company's procedures if you can take off prior to the shorter holdover, then off you go. If you're between the two holdover times, you can depart after a pre-flight inspection (ie one of us goes down to evaluate the wing from the inside, for whatever it's worth). If the longer holdover time is exceeded, then an (exterior) pre-flight check is required, and realistically (especially on a big a/c like a B747 or 380) that quite simply is not going to happen. In practical terms, it means back to the de-icing pad, or back to the pub!

[nitpicker330]

BARKINGMAD----The outside check is a REQUIREMENT under our operating manual using the Transport Canada guidelines if the longer HOT has expired :ok:


It's nothing to do with being scared of bad people down the back :D

[BARKINGMAD]

"What makes you more qualified? What training have you received that makes you qualified to determine whether deicing or a new application of deicing is required? Or is it just assumed that you know? How does your possible training compare to the person the ground?"

Maybe 16 years military plus 26 years civilian flying, including 747s, qualifies me for making a some sort of a safe assessment.

But doubtless some EASA gnome will insist I go on a 4 hour training course to prove that I can recognise aerofoil contamination when I see it?

I'm NOT querying ignoring national rules requiring an external operator.

My main point was that the de-icing crews operating in 60N were surprisingly unaware that their de-icing operation was inadequate and needed repeating at great cost of fluid and time.

I have to presume their training was inadequate as de-icing operators and hope that the Canadian "assessors" are better prepared?

[777-X]

A long time ago I was told that a visual check can confirm that there is contamination, but it can not confirm that there is no contamination.

Consequently, as positive confirmation of the absence of contamination is required, a visual check is not valid.

Only a tactile check will confirm the absence of contamination. The logic of this is missed even in the most detailed and latest references.

It follows that a check from the cabin or flight deck is invalid, except to confirm that there is contamination and that you need to de-ice, but it can not confirm that it is safe to go.


- A visual check is not valid -

[flyboyike]

It was my understanding that at my previous airline long before I was hired there, on serious ice days, one of the assistant chief pilots would sit in a pickup truck not far from the hold line and inspect airplanes taxiing up. I, however, never witnessed any such thing myself.