Go Back  PPRuNe Forums > Other Aircrew Forums > Cabin Crew
Reload this Page >

Interesting CHIRP Question!!

Wikiposts
Search
Cabin Crew Where professional flight attendants discuss matters that affect our jobs & lives.

Interesting CHIRP Question!!

Thread Tools
 
Search this Thread
 
Old 8th Nov 2009, 15:10
  #21 (permalink)  
 
Join Date: May 2009
Location: A whole new world now!!
Posts: 227
Likes: 0
Received 0 Likes on 0 Posts
FOK or indeed any pilot can I just ask a question as this thread is actually giving me a much better insight into ice awareness as an SCCM because the F/D are posting.

Assuming that what is photographed was not evident on take off (the Chirp poster says it was) if I came to you prior to landing with my concerns as photographed what could the Pilots do to sort out the performance issues you state? Would we be in danger on descent/landing with ice on the wing?

Sorry if I look stupid to the F/D here but as far as I know and am taught ice on the wing is not good and needs to be flagged up. If we have got as far as the situation photographed in flight what implications could this have on landing?
lowcostdolly is offline  
Old 8th Nov 2009, 18:53
  #22 (permalink)  
 
Join Date: Sep 2007
Location: UK
Posts: 441
Likes: 0
Received 0 Likes on 0 Posts
lowcostdolly

I would never consider a question from the cabin crew to be 'stupid' - in fact most pilots appreciate interest being shown. Particularly important in respect of safety issues.

I don't know the history of the photograph, but that amount of ice on the wings would pose serious issues if present on the approach and landing.

The amount I have come across has been no more than a frost-like covering on landing.

My advice would be to report ANYTHING you're not happy with to the flight deck - which is the basis of all good CRM in any event.

That crash of a B737 into the Potomac River a few years ago (mentioned above) was caused, amongst other things, by snow on the wings at take-off - and at least one member of the cabin crew had seen it (sorry if you know that already as it's a common example used during SEP training, as you're no doubt aware). I'll never forget the first time I saw the video of that man diving in to rescue the stewardess - brings tears to your eyes!

Better safe than sorry!

What you would do in that situation is a very good question. It would be difficult to dislodge quickly as only the leading edges of the wings having a de-/anti-icing capability. The fuel can get very cold at cruising altitude, particularly over a period of time, and this causes the ice to form if the aircraft flys through cloud. I've never come across anything like this forming in flight where it wasn't present on the ground (others in colder climes may have?). It would be a serious issue and if the destination was cold. Although the speed of the aircraft through the air causes some heating, it is unlikely to be removed if present during the descent. All that would be available would be either to hold (if in warm air and subject to fuel available) or to increase the approach speed (and therefore the lift available), but there are no tables available to the pilot to calculate the performance reduction/performance required in the QRH (the book the pilot uses to manually calculate performance).

All this proves one thing - ice or snow on the wings, particularly at departure, is a BAD THING!

KR

FOK
FlyingOfficerKite is offline  
Old 8th Nov 2009, 18:57
  #23 (permalink)  
Dit
 
Join Date: Apr 2006
Location: Europe
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Basically I would fly the approach at a higher speed so the wing was further from the stall speed, which may now be higher than it should be due to the snow on the wing. I don't know of any Boeing advice or performance figures for this situation (for my a/c or any other) so personally I would add the maximum allowable increase to the speed, double check the landing distance required at the increased speed and the amount available, then fly a normal approach.
Dit is offline  
Old 8th Nov 2009, 19:20
  #24 (permalink)  
 
Join Date: Jan 2000
Location: Long Beach
Posts: 349
Likes: 0
Received 2 Likes on 2 Posts
For those who want to read the full available story behind this, it is in CHIRP Air Transport Feedback No. 92, in PDF format, here

CHIRP

Starts on page 11 under 'Cabin Crew Reports'.
deeceethree is offline  
Old 8th Nov 2009, 21:01
  #25 (permalink)  
 
Join Date: Feb 2005
Location: Correr es mi destino por no llevar papel
Posts: 1,422
Received 1 Like on 1 Post
Originally Posted by A3575
Colleague of mine often flies into China and on countless occasions has seen local big jets taking off with ample snow on top of the wings yet they don't crash. This suggests that snow on the wings is not always fatal. I presume it depends on a complicated combination of type of wing design, amount and texture of the contamination, airspeed at VR and maybe other factors.

Originally Posted by moosp
Boeing have done a lot of studies recently sticking expanded polystyrene blocks onto the upper surface of a wing to simulate snow build up. They had observed that certain operators of Boeing aircraft around the world have survived for years after taking off with snow on the upper surfaces of the wing, which we thought, as pilots anyway, would lead to disaster.
I really have to borrow the phrase from EK Gann's masterpiece. I'll just rephrase it a bit:

The trouble with most pilots is that you are spoiled. And lazy. You have never taken the trouble to learn aerodynamics and statistics properly.

Ideally, minimum take-off safety speed (V2) clean wing at take off gives you 20% stall speed margin which roughly equates to taking off with 69.4% of theoretical maximum possible lift. More realistic figures are 13% and 78.3%, respectively (that's where Vs1g comes from). Now if you take-off with ice or snow contaminated wing, not a single person in the world has a vaguest notion of how much did you degrade those margins - "complicated combination of type of wing design, amount and texture of the contamination, airspeed at VR and maybe other factors" notwithstanding. As long as you have 0.1% of lift to spare, you live - most likely fat, dumb and happy. If you get short by 0.1%, your survival is far from being guaranteed.

Taking off with ice on the wings does not necessarily kill you, it merely reduces your chances of having mishap at T/O down to unacceptable level, from one in a billion to one in a... well it's impossible to calculate for each specific take-off but it can easily get into one in a ten. Most of the safety related items work the same way; they don't kill you outright, they merely increase your chance of getting killed. As a pilot, you can make successful ( defined as being completed without major incident or accident) flight while being drunk, while having hangover, while flying fatigued, by making ILs approach with CAT1 aeroplane, on CAT2 ILS, down to CAT 3 minimum, yet your chances of getting killed would be so severely increased that given time, there will be a day on which lady Luck looks the other way and there's smoking hole and a few funerals to be arranged.

Learn statistics and learn them well - it's good vaccine against acquiring invulnerability attitude through repeatedly breaking the rules.

Boeing recommendation is at odds with many a local aviation authority rulings. No aeroplane registered in my country is allowed to take off with any ice or snow on the upper wing surface, no matter what messieurs Boeing, Airbus, Tupolev, Cessna, Bombardier, Cirrus or whoever say. Wing's upper surface is the stupidest place in known universe to save few bucks on glycol.

Chances are that Air Florida crew would have got away with holdover expired but EPR probe unobstructed. Or within holdover time but with reduced thrust as a consequence of EPR probe frozen over. Now we all know that "God! Look at that thing!" callout is reason enough for rejected take-off.

Originally Posted by Flying officer kite
Judging by the altitude of the aircraft it is more likely this icing has been caused by the aeroplane passing through moist air with cold soaked fuel tanks.
No way. Once you're past 100 kt, nothing can freeze behind maximum curvature of the wing. No cloud, no fog, no snow, no freezing rain, nothing. Supercooled large droplets can occasionally refreeze way beyond leading edge, but even they can't move past first quarter of the aerofoil. Any and every contamination behind quarter of the wing chord is ground acquired.

Clandestino, latent flight attendant.
Compliant with the last point.
Clandestino is offline  
Old 8th Nov 2009, 22:45
  #26 (permalink)  
 
Join Date: Feb 2002
Location: UK
Age: 58
Posts: 3,505
Received 174 Likes on 95 Posts
I Quote....

"Takeoff with light coatings of cold-soaked fuel frost on upper wing
surfaces is allowable, provided the following conditions are met:
• the frost on the upper surface is less than 1/16 inch (1.5 mm)
in thickness
• the extent of the frost is similar on both wings
• the frost is on or between the black lines defining the
allowable cold-soaked fuel frost area (see figure) with no ice
or frost on the leading edges or control surfaces
• the ambient air temperature is above freezing (0°C, 32°F)
• there is no precipitation or visible moisture (rain, snow, drizzle
or fog with less than 1 mile visibility, etc.)"

from a Boeing Manual.
Don't give a monkeys what Boeing say.

CAA/FAA say otherwise as does my employers de-icing manual.

Ice on upper surface = nogo. De-ice. End of.
TURIN is offline  
Old 9th Nov 2009, 01:00
  #27 (permalink)  
 
Join Date: Apr 2005
Location: the balmy beautiful south
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
FAKE

The picture looks like a photoshopped fake to me
DHC6tropics is offline  
Old 9th Nov 2009, 02:36
  #28 (permalink)  
 
Join Date: Feb 2006
Location: Essex
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Definately not formed in flight. They got airborne with that for sure. Easily done id say too. Walk around done in the dark, under wing ice hard to spot, forgets to look at top of wing. Leading edges all clear. Launch.

There but for the grace of god go I.
I Just Drive is offline  
Old 9th Nov 2009, 09:31
  #29 (permalink)  
 
Join Date: Jun 2001
Location: UK.
Posts: 4,390
Likes: 0
Received 1 Like on 1 Post
Turin is correct.
NO ICE OR SNOW OR FROST AT ALL on UPPER surface of wing whether caused by precipitation or cold fuel.
The UNDERSIDE of the tailplane/stabiliser should be clean.

That photograph, if genuine, is absolutely outrageous!

Since I usually fly BA, it's unlikely that I'll ever have to take 'direct action' however I did, some years ago, notice some frozen water droplets on another operator's wing. I was sure they were going to de-ice off stand - they weren't

Last edited by Basil; 9th Nov 2009 at 09:49.
Basil is offline  
Old 9th Nov 2009, 09:43
  #30 (permalink)  

Still Trampin' the Ramp
 
Join Date: Nov 2000
Location: Right in the middle of UK
Age: 76
Posts: 282
Likes: 0
Received 0 Likes on 0 Posts
EASA state -
Quote;
A pilot shall not take off in an aircraft that has:
frost, snow, slush or ice on any propeller, windshield or power plant installation or on airspeed,
altimeter, rate of climb or flight altitude instrument systems;
snow, slush or ice on the wings or stabilisers or control surfaces, in gaps between the airframe and
control surfaces, or in gaps between control surfaces and control tabs, or any frost on the upper
surfaces of wings or stabilisers or control surfaces. For this reason a contamination check of the
aircraft surfaces shall be performed prior to departure.
Unquote.

There doesn't seem much room for argument there!

RT
RampTramp is offline  
Old 9th Nov 2009, 11:18
  #31 (permalink)  
 
Join Date: Jan 2000
Location: U K
Posts: 469
Likes: 0
Received 0 Likes on 0 Posts
Shame on CHIRP and shame on the individual that has started this with a complete work of fiction.
If you look at this photograph closely you can see it is a complete fake!.
CHIRP should have looked at this more carefully before taking it up.
All involved should get a grip, and I hope CHIRP have another look at this and take the appropriate action against the individual who thinks it was a good idea.
BALLSOUT is offline  
Old 9th Nov 2009, 11:50
  #32 (permalink)  
Moderator
 
Join Date: Feb 1998
Location: Europe
Posts: 3,051
Likes: 0
Received 0 Likes on 0 Posts
Hi BALLSOUT,
I see from your profile that youŽre a 737 Capt. So no doubt you have more knowledge about this matter than most of us here on the CC forum.
Contamination is something we do get training in, in fact itŽs one of the spearpoints of this yearŽs SEP recurrent at my mob. We reviewed the Potomac accident already mentioned on this thread.

But even after having spent 5 years on the 737 in the past and regular training on contamination, I canŽt say IŽd be confident to make a definitive statement about wing contamination one way or anther.
See ice/snow on wing => alert pilots
If youŽd care to explain a bit more about why you believe this pic is a fake, IŽd be grateful.
flapsforty is offline  
Old 9th Nov 2009, 12:37
  #33 (permalink)  
 
Join Date: Jan 2000
Location: U K
Posts: 469
Likes: 0
Received 0 Likes on 0 Posts
Hi Flapsforty, My statement is not based on my knowlege of the 737, I simply downloaed the photograph and zoomed in on it and it is clearly a fake. You can see that the wing has been cut out of another photograph and pasted into the airborne view. I am confident that this is a prank that CHIRP should have worked out before going any further with it. I expect this will leave a lot of people with egg on face.
If I were to use any of my technical knowlege or experience. I would say if the wing did in fact have this much snow on it, the aircraft would be unlikely to even get off the ground. If it did, once it had a few hundred knots of air over it, the snow would probably have come off. It would certainly have started to come off in large chunks.
Snow and ice on aircraft wings is a serious problem that has killed many people and no doubt will kill many more. I am 100% convinced however, that this is in fact just a sick prank!
For the record, If I was a passenger on an aircraft with this much snow on the wings. If the crew didn't have it removed I would stand up and insist it be done. If they were unwilling to listen to me I would remain on my feet preventing the cabin from being secure until they either offloaded me or de-iced the aircraft!
BALLSOUT is offline  
Old 9th Nov 2009, 12:59
  #34 (permalink)  
737
 
Join Date: Apr 2000
Location: 500' above Ireland
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
It was a Ryanair 737-800.
737 is offline  
Old 9th Nov 2009, 16:35
  #35 (permalink)  
 
Join Date: Sep 2007
Location: UK
Posts: 441
Likes: 0
Received 0 Likes on 0 Posts
I've just received CHIRP through the post today.

Having read the article, some of my previous comments are not applicable.

I'm not sure about the article being fake, particularly if CHIRP have contacted the operator, as stated in the article. If it is a fake it would show a lack of due diligence on the part of CHIRP and will no doubt result in an appropriate response in due course if the operator has indeed been wrongly accused. I find this hard to believe.

The pattern of snow on the wings suggests it is in the region of the fuel tanks, with the leading edge (de-iced) and wing tip not being covered.

If it is a bona fide report, then it shows the degree of contamination which a B737 will tolerate without falling out of the sky - which I trust will enable pilots to gain an insight into the issue rather than think if they depart with snow or ice on the wings all is not lost!!!

KR

FOK
FlyingOfficerKite is offline  
Old 9th Nov 2009, 21:29
  #36 (permalink)  
 
Join Date: Nov 2000
Location: Dre's mum's house
Posts: 1,432
Likes: 0
Received 0 Likes on 0 Posts
737

It was a Ryanair 737-800
Your logic being.........?
The Real Slim Shady is offline  
Old 10th Nov 2009, 13:46
  #37 (permalink)  
 
Join Date: May 2009
Location: A whole new world now!!
Posts: 227
Likes: 0
Received 0 Likes on 0 Posts
FOK thank you Will carry on as normal then.....see ice= get advice!! Our drivers will always look at anything untoward

I know I'm being boring here but can I just ask if you guys know something about CHIRP that I don't?

Reporting through CHIRP is supposed to guarentee anonimity yet we have somebody on here posting that this was an FR 737-800. How would 737 know? All the FR 737's I've seen around have huge winglets with their logo on. Do CHIRP let these things slip?

Ballsout if this is a fake I didn't see it. I did however think it was unbelievable the plane took off without incident. That was only based on my memories of Potomac and the very limited ice awareness training given to CC during CRM. I know nothing of the physics of this and the F/D posting on here have given me greater insight.

CHIRP guarentee they will destroy all personal records of the person giving the report once the investigation is concluded and their posts indicates it was. How then are they supposed to take action against anyone if this is indeed a fake? Your post indicates they can do this.

I ask because if ever, God forbid, I did have a safety concern not adressed by the F/D I would go through CHIRP because I would want my anonimity assured. My company's management make all the right noises re safety reporting but I know what happened to a friend of mine in respect of doing this openly. It would have been CHIRP for me until I saw these posts.

Clarification appreciated
lowcostdolly is offline  
Old 10th Nov 2009, 20:02
  #38 (permalink)  
 
Join Date: Sep 2007
Location: UK
Posts: 441
Likes: 0
Received 0 Likes on 0 Posts
lowcostdolly

You're welcome - I'm pleased you consider the above F/D comments have been useful.

In so far as anonymity of the CHIRP reports is concerned, I am looking at my copy as I type.

The back page, as you are aware, states amongst other things that: '1. Your personal details are required only to enable us to contact you for further details about any part of your report...'

It is totally confidential as far as I am aware - it wouldn't work otherwise. The article does, however, mention at the beginning that the report 'has also been published in the Autumn issue of Cabin Crew FEEDBACK to raise crew awareness.' I don't know what terms and conditions are attached to that publication.

All I would say is this is such a serious incident that the matter is being treated with an appropriate degree of interest by CHIRP in that 'The reporter's concern, together with photographic evidence, was forwarded to the management of the operator concerned'. However it is more likely that the incident became 'common knowledge' among the cabin crew and flight deck and this is how the story was 'leaked'.

I cannot believe that any pilot seeing that photograph would be anything other than appalled and it beggars belief if the 'facts' concerning the article are correct.

The whole point of confidential reporting is that it enables safety matters to be addressing without the input and possible consequences of management finding out and taking action against the employee.

This very fear, present in most employees, unfortunately shows that commercial and corporate concerns take precedence over safety matters in reality no matter what hype PR departments and management might 'spin' in their advertising and publications. Safety is a dirty word, it costs money and a perceived lack of it has a profound affect on the perception of the airline with the travelling public.

That statement might be seen as controversial but ask yourself the question - when was the last time airlines VOLUNTARILY incorporated a safety feature UNILATERALLY into their own aircraft to enhance safety. Never as far as I am aware.

Yes we have bullet-proof doors, oxygen masks, life-jackets and smoke hoods for the crew. Which airline was it that first introduced these items and advertised them as a selling point to their customers? No one - the airlines were driven kicking and screaming by the regulatory authorities to install them as a consequence, in many cases, of an accident. In fact the majority of safety features and SOPs in modern airliners can be traced back to a particular incident or accident. Boeing have, within the past few years, revised their Checklists for the B737 because of the problems with pilots forgetting to manage the pressurisation systems correctly. Safety learnt by experience.

No wonder then that the prospect of openly reporting such a matter to management is likely to result in a less than enthusiastic response.

Think of duty hours - do airlines accept that crews get fatigued and roster less than the maximum hours - of course not, they use CAP371 to its limit. The airline that has reportedly been involved in this incident is famous for cutting costs.

Long live CHIRP and NEVER consider holding back on a report if the matter warrants such a article. That's how we and others learn and survive.

For my part I discontinued a duty once because I felt too fatigued. I had the desired rest but was too tired. I asked for a relief crew to take my place after the first rotation. I didn't report 'fatigue' just a 'tummy bug' because I knew how management would react (as we all do). As cabin crew and pilots all know it's the management who should be on CRM and SEP courses - maybe then they'd have more idea about the consequences of their actions.

It'll never happen because MONEY rules OK.

Keep reporting. Stay professional!

KR

FOK
FlyingOfficerKite is offline  
Old 10th Nov 2009, 22:48
  #39 (permalink)  
 
Join Date: Jan 2000
Location: U K
Posts: 469
Likes: 0
Received 0 Likes on 0 Posts
lowcostdolly, I think FlyingOfficerKyte has covered all that you asked about.
I expect we will just have to wait for a while to see what comes of it. No doubt it will eventually find it's way onto PPRUNE if it was fake, who's aircraft it is, and the outcome of any enquiry.
The down side of this is, if in deed it is not a fake. People may decide it's actually ok to fly with a bit of ice on the wings after seeing the photo!
BALLSOUT is offline  
Old 11th Nov 2009, 09:54
  #40 (permalink)  
 
Join Date: Jul 2000
Location: Nirvana..HAHA..just kidding but,if you can tell me where it is!
Posts: 350
Received 0 Likes on 0 Posts
I think that the apparent (curved) loaded wing and appearence of a flash reflection from the cabin window argue against a fake. The wing does appear to be in flight, therefore contraindicating the need to cut and paste it from a different photo. If the snow on the surface has been cut and pasted from a different photo, it is a very clever fit!
The maxim here for all CC to think about..if it looks different, communicate with the pilots. Never ever seen this in flight..not even on a DC3, that fly's slow enough for sparrows to hold a tea party on the wing!
Yaw String is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.