Tech Log The very best in practical technical discussion on the web

AF447

Old 6th Jun 2009, 22:08
  #381 (permalink)  
 
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 81
Posts: 1,330
Received 0 Likes on 0 Posts
0214z Position?

I noticed when searching the Brazilian Air Force website that they are using an 0214z position of 3 16 28N 30 22 28W which is at variance with the position that has previously been reported (3 34 40N 30 22 28W).

The Brazilian position is on track and 18NM south of the other, and they have stated that the recovered bodies etc. were found 69.5km (35NM) north-west of their 0214z position.

mm43
mm43 is offline  
Old 6th Jun 2009, 22:08
  #382 (permalink)  
CR2

Top Dog
 
Join Date: May 2000
Location: Close to FACT
Age: 55
Posts: 2,098
Likes: 0
Received 0 Likes on 0 Posts
Tan, moderators are unpaid members of this site. We have lives and do not sit here watching every post "live". Sitting in many different time zones too. It's midnight in central europe right now, believe it or not the odd mod might just be asleep.

Perhaps (and I am NOT going to check), said post has been posted and deleted 5 times already - repetition.

I suggest everyone re-reads Danny's last post to close the previous AF thread. Give the R&N mods a break, ok? I don't mod here, just passing on a thought for you all.


EDIT: AHH. PPT, you got there first. Delete this if you wish.
CR2 is offline  
Old 6th Jun 2009, 22:12
  #383 (permalink)  
 
Join Date: Jul 2005
Location: エリア88
Posts: 1,031
Likes: 0
Received 0 Likes on 0 Posts
Air France
Press release N 12

Update on anemometric sensors

Paris, 06 June 2009 - 23:09 local time

Following the many questions which have appeared in the media on the issue of the Pitot probes in its fleet (the Pitot probe is an instrument which measures the air speed of the aircraft), Air France wishes to make the following clarifications:

1) Malfunctions in the Pitot probes on the A 320 led the manufacturer to issue a recommendation in September 2007 to change the probes. This recommendation also applies to long-haul aircraft using the same probes and on which a very few incidents of a similar nature had occurred.
It should be noted that a recommendation from the manufacturer gives the operator total freedom to apply the corresponding guidelines fully, partially or not at all. Should flight safety be concerned, the manufacturer, together with the authorities, issues a mandatory service bulletin followed by an airworthiness directive (AD).

The recommendation to change the probes was implemented by Air France on its A320 fleet where this type of incident involving water ingress had been observed. It was not implemented on the A340/330s as no such incidents had been noted.

2) Starting in May 2008 Air France experienced incidents involving a loss of airspeed data in flight, in cruise phase on A340s and A330s. These incidents were analysed with Airbus as resulting from pitot probe icing for a few minutes, after which the phenomenon disappeared. Discussions subsequently took place with the manufacturer. Air France asked for a solution which would reduce or eliminate the occurrence of these incidents. In response to these requests, the manufacturer indicated that the probe model recommended for the A320 was not designed to prevent such incidents which took place at cruise levels, and reiterated the operational procedures well-known to the crews.

In the first quarter of 2009 laboratory tests suggested, however, that the new probe could represent a valuable improvement to reduce the incidence of high altitude airspeed discrepancy resulting from pitot probe icing, and an in service evaluation in real flight conditions was proposed by Airbus. Without waiting for the in service evaluation, Air France decided to replace all its probes and the programme was launched on 27 April 2009.

Without making any assumptions as to a possible link with the causes of the accident, Air France speeded up this programme and reminded its pilots of the current instructions issued by the manufacturer to cope with the loss of airspeed data.
Mercenary Pilot is offline  
Old 6th Jun 2009, 22:15
  #384 (permalink)  
 
Join Date: Jun 2009
Location: US
Posts: 497
Likes: 0
Received 0 Likes on 0 Posts
WNC, Something must have distracted them from deviating. If they had been monitoring their radars and they were working properly they would have deviated. It is unlikely all the failures started before the turbulence of penetrating the cells because it is unlikely all the bad luck came at once. More than likely the turbulence caused the failures because of icing and power interuptions. Now that they have found some wreckage and passengers so maybe they can find the black boxes. I think Air France is hoping they are never found.
p51guy is offline  
Old 6th Jun 2009, 22:25
  #385 (permalink)  
BarbiesBoyfriend
Guest
 
Posts: n/a
There is wx that will break ANY aircraft.

Wx like this existed that night and this aircraft was in it.

All this analysis of messages from the aircraft seems to be a matter of great interest to ppruners, but to what purpose?

I'm usually the last to agree with the 'lets wait for the investigation results' posters, but on this occasion I am with them 100%.

It was the weather that did it.

I hope they find the FDR and CVR because then we might find out why they flew into that awful wx.

Personally, I avoid it.

Edit to add: The main reason I am so keen to avoid is that one day I flew into a big 'ol Cb (probably 10% of the AF447 one) and got shaken ****less, but survived. Not pretty.

Last edited by BarbiesBoyfriend; 6th Jun 2009 at 22:35.
 
Old 6th Jun 2009, 22:25
  #386 (permalink)  
 
Join Date: Sep 2008
Location: MI
Posts: 570
Likes: 0
Received 0 Likes on 0 Posts
Dani -
So it's pretty likely that they first entered into a storm system, then they experienced all the problems.
Not sure there's enough information to conclude that.

We should therefore concentrate on arguing about why the crew should have entered a thunderstorm system.
The list of weather related aircraft accidents is way too long. There are still pilots who do not respect weather unfortunately. Guidlines are posted in all Flight Operations Manuals (or at least they should be !) on weather avoidance. When you are able to answer your question, "Why?", we will have made progress. Many pilots are "afraid" to carry extra fuel to avoid weather along their planned route because of fuel monitoring programs in place at some airlines. Others are 'management' pilots who think they're doing their company right by saving the fuel. Deviation fuel is cheap insurance.
DC-ATE is offline  
Old 6th Jun 2009, 22:29
  #387 (permalink)  
 
Join Date: Sep 2002
Location: La Belle Province
Posts: 2,181
Likes: 0
Received 0 Likes on 0 Posts
An interesting piece of info on the pitot probes indeed. My attention was caught by one particular sentence:

Should flight safety be concerned, the manufacturer, together with the authorities, issues a mandatory service bulletin followed by an airworthiness directive (AD).
That's not strictly true. It is the case that all Mandatory SBs (and ADs) arise from safety concerns. But I do not believe it to be the case that all flight safety issues automatically result in a mandatory SB or AD.

The Canadian Aviation Regulations, for example, state:

593.02 Unless the Minister considers that an alternative action to an airworthiness directive will ensure an equivalent level of safety, the Minister shall issue, in the form and manner set out in Chapter 593 of the Airworthiness Manual, an airworthiness directive in respect of an aeronautical product for which a type certificate has been issued, or accepted, by the Minister where

(a) an unsafe condition exists in the aeronautical product and the condition is likely to exist or develop in other aeronautical products;

(b) it has been found, subsequent to the issuance of the type certificate, that the aeronautical product does not conform to the requirements of the basis of certification for the type design of the aeronautical product;

(c) it is necessary to modify or cancel the requirements of an airworthiness directive issued by a civil aviation authority having jurisdiction over the type design of the aeronautical product because the Minister considers the airworthiness directive inappropriate for reasons related to the environment, safety, the delayed receipt of an instruction issued by a foreign civil aviation authority or reliance on foreign legislation; or

(d) it is necessary to modify or cancel a Canadian airworthiness directive that is in force, because a condition referred to in any of paragraphs (a) to (c) has changed or ceased to exist.
(my emphasis).

So if the OEM proposes a recommended SB, and believes (and convinces their authority) that the normal replacement cycle, or economic incentive to upgrade, or whatever, will get the parts changed out in time, then no AD is required.

It should be noted in that context that AF was sufficiently concerned to start the replacement of the pitots without needing an AD. Summary: the pitots may well have been a threat to flight safety, just people thought it was of low enough risk to carry the problem and address it without AD-level action.

edit to add that I have no reason to believe EASA are any different to TCCA in this regard, nor the FAA. I know of issues in fact where TCCA have issued an AD for their OEM, but EASA haven't required one for theirs. And I'm sure there are examples in fact of every combination possible)
Mad (Flt) Scientist is offline  
Old 6th Jun 2009, 22:34
  #388 (permalink)  
 
Join Date: Sep 2004
Location: Sandpit
Posts: 361
Likes: 0
Received 0 Likes on 0 Posts
Fuel savings

The pencil pushers in their offices are part of this problem, every flight is different, the decision how much fuel is required is the discretion of the Captain. I don't think fuel was a problem on this flight, however there is a tendency in these Airbus planes to fly too high in the coffin corner.
I always try to prevent the FO's to request higher level too soon. They always push to get a higher level.
FlyingCroc is offline  
Old 6th Jun 2009, 22:41
  #389 (permalink)  
BarbiesBoyfriend
Guest
 
Posts: n/a
The ever more rigorous application of strictly enforced SOPs, while in normal ops is a GOOD THING, can lead to trouble in abnormal ops.

It encourages new pilots to think that they are 'bulletproof' as long as the stick to the SOP.

Flying is a dangerous thing, made safe with much work.

There is NO substitute for experience and a great respect for ones own limitations, the aircrafts limitations and the weathers complete lack of limitations.

Be wary.
 
Old 6th Jun 2009, 22:42
  #390 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
Likes: 0
Received 0 Likes on 0 Posts
flyingcroc

you have great wisdom!

I've found 4000' below flightplan alt gives a nice buffet margin width...and not too much more fuel burn.
protectthehornet is offline  
Old 6th Jun 2009, 22:45
  #391 (permalink)  
 
Join Date: Jun 2009
Location: California
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
DC-ATE wrote:
Many pilots are "afraid" to carry extra fuel to avoid weather along their planned route because of fuel monitoring programs in place at some airlines. Others are 'management' pilots who think they're doing their company right by saving the fuel. Deviation fuel is cheap insurance.
The reasons that pilots might or might not request extra fuel are speculative, so let's put that part aside for now.

If the crew had taken on extra fuel, it would be to AF's advantage to reveal that fact to illustrate that safety was paramount from the start of the flight. Yet unless all of us here missed it, AF has not said whether the crew requested and got deviation fuel. Therefore it appears to me more likely than not that the crew did not have extra fuel for deviation.

I really want to be proven wrong on this: I have several AF flights booked for this summer.
WNcommuter is offline  
Old 6th Jun 2009, 22:50
  #392 (permalink)  
 
Join Date: Sep 2008
Location: MI
Posts: 570
Likes: 0
Received 0 Likes on 0 Posts
As a Co-Pilot, I was fortunate most of the time to fly with Captains who were not worried about carrying extra fuel if they felt they needed it. They were the most comfortable to fly with. Some others I was able to convince to add fuel for various reasons. Some simply would not. Those I avoided. When I elected to fly Captain, naturally, I had all the fuel I wanted. Did I get called in the 'office' occasionally? Yes. I never changed my philosophy.

Whether or not fuel was an issue on this flight we do not know. The fuel load had not been made available yet I do not believe. It would be interesting to know how much 'extra' fuel was aboard. There again, flying too high might have been because of fuel issues. However, if you're too heavy, you're going to burn more than you save just trying to get up and maintain the higher altitude. Maybe it's time to institute a 'fuel surcharge' and divide the cost of an extra thirty minutes fuel among the passengers. I'm sure they wouldn't mind.
DC-ATE is offline  
Old 6th Jun 2009, 22:53
  #393 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 4,569
Likes: 0
Received 1 Like on 1 Post
I've got to admit that I'm confused about the strong opinions being expressed about the crews decision to fly into a thunderstorm.

I have to ask myself what did the crew know and when did they know it?

And just how do the posters decribe and define a thunderstorm relative to a 3 dimensional module?

I never thought that it was possible to set a tract that would avoid all storm fronts by 100 miles or so, but instead to set an altitude and tract to avoid the most dangerous part of the storm. So to me the mere fact that some turbulence and lightning are reported does not convince me at this time that the crew acted carelessly.
lomapaseo is offline  
Old 6th Jun 2009, 22:55
  #394 (permalink)  
 
Join Date: Aug 2007
Location: The sky
Posts: 342
Received 7 Likes on 2 Posts
Fuel would not have been an issue. Period.

No sane aviator would penetrate a CB just because they might not reach the destination with div+reserves or even reserves.

If a fuel shortfall is identified you burn as much of it as you need to to avoid weather enroute and replan a closer destination for a tech stop. On the route in question Faro or Lisbon are ideal, in extremis the Canaries are closer.
Locked door is online now  
Old 6th Jun 2009, 22:56
  #395 (permalink)  
CR2

Top Dog
 
Join Date: May 2000
Location: Close to FACT
Age: 55
Posts: 2,098
Likes: 0
Received 0 Likes on 0 Posts
DC-ATE, have you seen the price of a ticket recently (or a ton of cargo for that matter?) The fuel surcharges equal or exceed the "cost" as is..... It is how our dear industry manages to make $ from time to time.
CR2 is offline  
Old 6th Jun 2009, 22:58
  #396 (permalink)  
 
Join Date: Apr 1999
Location: UK
Posts: 1,691
Likes: 0
Received 0 Likes on 0 Posts
Where has the idea that they didn't have enough fuel, or should have loaded more, appeared from? If they took extra fuel great. If they didn't they could have deviated around the weather and dealt with the shortfall later, like any professional aircrew would. I've found myself weaving around thunderstorms in the company of Air France in another region of the world and they were many miles further off track than we were without too much concern. If that is representative of corporate practice, and I've no reason to doubt it is, then we can put the fuel concerns to bed.
Carnage Matey! is offline  
Old 6th Jun 2009, 22:59
  #397 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
Likes: 0
Received 0 Likes on 0 Posts
regarding flying into a thunderstorm

perhaps the best available information to the crew lead them to the route they followed. much has been written about the shortcomings of even the most modern of wx radar.

I think, until a CVR recorder is found, that we should assume the pilots followed a reasonable course of action based on the information they had.
protectthehornet is offline  
Old 6th Jun 2009, 23:06
  #398 (permalink)  
Just another number
 
Join Date: Jun 2001
Location: UK
Age: 76
Posts: 1,077
Likes: 0
Received 0 Likes on 0 Posts
WNcommuter

There is no such thing as 'deviation fuel'. All aircraft carry 'contingency fuel' which is intended to cover weather deviations amongst other things.

Dave
Captain Airclues is offline  
Old 6th Jun 2009, 23:10
  #399 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
Likes: 0
Received 0 Likes on 0 Posts
captainairclues

I think we all fly in different worlds of flying...in my world we have contingency fuel for the unknown

we have fuel to destination

we have fuel to alternate

we have fuel for holding

so...let us all learn from each other
protectthehornet is offline  
Old 6th Jun 2009, 23:12
  #400 (permalink)  
 
Join Date: Mar 2007
Location: sydney
Age: 64
Posts: 82
Likes: 0
Received 0 Likes on 0 Posts
For the non-pilots who have an interest in this;

It's hard to explain to the uninitiated just how differently an aircraft flies when near the top of it's operating envelope compared to just a few thousand feet lower, and what these degradations and thin margins mean. If you're near the top end of that envelope, even something as little as a unforecast, sudden rise in temperatures aloft of 5 to 10 degrees can require immediate action (descent to a lower altitude because engine thrust isn't available in excess at altitude) because the top of the envelope is lowering...crashing down if the temp rise is quick enough.
Thanks AMF. For SLF such as me , this discussion is a fascinating eye-opener regarding the rationale behind these various parameters of high altitude, temperature change, weight, thrust ,AOA etc.
aussiepax is offline  

Thread Tools
Search this Thread

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.