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-   -   Air France severe turbulence, mayday call (https://www.pprune.org/rumours-news/397440-air-france-severe-turbulence-mayday-call.html)

aa73 30th Nov 2009 17:07

Air France severe turbulence, mayday call
 
http://avherald.com/h?article=42380873&opt=0

captplaystation 30th Nov 2009 17:23

Sure someone is going to accuse them of being a bit jumpy, but if they possibly had to descend to a lower level NOW to maintain buffer margin, making a Mayday call was undoubtedly the best option to keep everyone flying anywhere near them in the loop.
Some new Pierre Cardin slips needed methinks :eek:

daikilo 30th Nov 2009 18:34

Facts
 
Not saying this did not happen, but plane was late departing. It seems actual arrival at CDG was a few minutes early compared to ETA predicted after take-off.

B777FD 30th Nov 2009 20:53

"An Air France Airbus A330-200, registration F-GZCK performing flight AF-445 from Rio de Janeiro Galeao,RJ (Brazil) to Paris Charles de Gaulle (France), was enroute at FL380 overhead the Atlantic on airway UN741 just before waypoint DEKON about 680nm northeast of Fortaleza,CE (Brazil) and 750nm southwest of Praia (Cape Verde), when the crew called Mayday on the international emergency frequency indicating, they encountered severe turbulence and were descending to a lower altitude. The airplane was seen enroute at FL280 overhead France and landed safely at Paris Charles de Gaulle 6:40 hours after the emergency call."

This implies the aircraft descended to FL280 for the remainder of the flight. :confused:

Dash-7 lover 30th Nov 2009 23:15

Looking at the weather graphics it looks eerily similar to previous events. Glad they made it back ok.

Remember mayday situation is one in which a vessel, aircraft, vehicle, or person is in grave and imminent danger and requires immediate assistance. I wonder how far they were from the nearest diversion point? Obviously the crew reassessed the situation and felt ok to continue to CDG. Probably pretty frightening all the same.

daikilo 30th Nov 2009 23:27

Facts
 
These words in quotes "..." are from Aviation Herald, which does not make them facts.

Again, I do not say it did not happen, but I would like to see more proof, pls.

golfyankeesierra 1st Dec 2009 06:57


Remember mayday situation is one in which a vessel, aircraft, vehicle, or person is in grave and imminent danger and requires immediate assistance.
Well, also remember that it is not easy to get a reclearance in oceanic airspace for situations of i.e. weather deviation or unability to maintain altitude.
When reclearance cannot immediatly be obtained, there are procedures in force that include use of pilot's annex 2 "emergency authority".
Captplaystation's explanation seems much more rational then the "panic in the cockpit" one.

no sig 1st Dec 2009 07:58

The following from the ICAO North Atlantic MNPS Manual, presume the same procedures apply on the southern oceanic routes,

Chapter 11: Special Procedures for In-Flight Contingencies

11.1 INTRODUCTION

11.1.1 The following procedures are intended for guidance only. Although all possible contingencies cannot be covered, they provide for such cases as:

• inability to maintain assigned level due to weather (for example severe turbulence);

• aircraft performance problems; or

• pressurisation failure.

11.1.2 They are applicable primarily when rapid descent, turn-back, or diversion to an alternate aerodrome is required. The pilot's judgement will determine the specific sequence of actions taken, having regard to the prevailing circumstances.

11.2 GENERAL PROCEDURES

11.2.1 If an aircraft is unable to continue its flight in accordance with its ATC clearance, a revised clearance should be obtained whenever possible, prior to initiating any action, using the radio telephony distress (MAYDAY) signal or urgency (PAN PAN) signal as appropriate.

Whippersnapper 1st Dec 2009 10:33

I have heard other aircraft make Mayday calls for exactly this reason, including a BA 747. I have also witnessed an ATR refuse to use it and accept holding in severe icing after being denied a request to descend. So, which is correct and which was plain stupid?

If you believe the aircraft or occupants are in jeopardy and need to change course or level contrary to ATC clearance, you use Mayday. Simple.

clear to land 1st Dec 2009 11:02

By definition 'severe turbulence' means that the aircraft is uncontrollable, therefore a Mayday call should be almost an automatic response: after all, the pilots no longer have contol!

barstow 2nd Dec 2009 04:26

Indeed, the non-aviation community does not understand the need for mayday in this context.

The unauthorized departure from assigned altitude is in fact a mayday, even if the aircraft is not spiralling into the sea. The mayday is issued because the immediate threat to life is any other aircraft already in the FL descended to, in the area, and the people on board the transmitting aircraft.

Completely normal, and completely logical.

No need for alarm here, folks...

RoyHudd 2nd Dec 2009 09:22

Just do it.
 
It is often not possible to get an immediate clearance from Dakar. (They hardly qualify as Air Traffic "CONTROL" in any event. Same applies to most African airspace, in truth).

Best to announce one's manoeuvres on 121.5 and 123.45, preceded by PAN, and just take avoiding action from CB's or severe turbulence. Radio plus the use of TCAS allows one to stay clear of dangerous weather, with far less risk to all than that provided by severe wx in the ITCZ.

Mr Optimistic 2nd Dec 2009 11:53

any substance to this ?
 
The Avherald site has this comment from a user

'The 4th incident during the last 2 weeks on this route I think...'

any substance to it ?

keltic 2nd Dec 2009 15:25

Can I ask something?. Do extreme weather occur throughout the whole year in the ITCZ?. In which season are storms more likely to happen?.

fhegner 2nd Dec 2009 16:12

hey Keltic

Wiki is your friend:

Intertropical Convergence Zone - Wikipedia, the free encyclopedia


"The ITCZ appears as a band of clouds, usually thunderstorms, that circle the globe near the equator. In the Northern Hemisphere, the trade winds move in a southwesterly direction, while in the Southern Hemisphere, they move northwesterly. The point at which the trade winds converge forces the air up into the atmosphere, forming the ITCZ.[2]

The tendency for thunderstorms in the tropics is to be short in their duration, but can produce intense rainfall. It is estimated that 40 percent of all tropical rainfall rates exceed 25 mm per hour (one inch per hour). Greatest rainfall typically occurs when the midday Sun is overhead. On the equator this occurs twice a year in March and September, and consequently there are two wet and two dry seasons. Further away from the equator, the two rainy seasons merge into one, with one wet season and one dry season. In the Northern Hemisphere, the wet season occurs from May to July, in the Southern Hemisphere from November to February.[2]

The location of the intertropical convergence zone varies over time. Over land, it moves back and forth across the equator following the sun's zenith point. Over the oceans, where the convergence zone is better defined, the seasonal cycle is more subtle, as the convection is constrained by the distribution of ocean temperatures.

Sometimes, a double ITCZ forms, with one located north and another south of the equator. When this occurs, a narrow ridge of high pressure forms between the two convergence zones, one of which is usually stronger than the other."


Microburst2002 2nd Dec 2009 16:51

Hi keltic
The ITCZ can be considered as the thermal ecuator.
Depending on the season and also monsoon effects, the ITCZ shifts north or south, but if you are in the ITCZ it doesn't matter what is the season. You are in it, and that's what matters.
If you have to fly from A to B and the ITCZ is in the middle, you have to cross it whether you like it or not. That's the problem. From South America to Europe, that is the case.

TopBunk 2nd Dec 2009 18:00

one of the problems is that the powers that be (in Frankfurt or London or wherever) decided that the ITCZ should be removed from the SigWx charts:mad:.

You now have to rely on knowledge, or look at the forecast winds on your Plog to see where they shift, or look at the CB forecasts to, at best, guess where the ITCZ may lie on a given day.

If anyone anywhere does not believe that the ITCZ is 'significant weather' they need flying through repeatedly it until they submit as a screaming crying wreck, the numpties.

keltic 2nd Dec 2009 18:36

Thanks for the replays. I have flown many times to Argentina and Brazil usually in end of march, beginning of April, and I have to admit that I have never found any significant problem. Even sometimes no many clouds in the area. Some turbulences, but nothing drammatical.

Sorry for the offtopic, but not being a pilot, this kind of dark area, was something completely new for me. Weather is such an amazing issue in aviation, which I think we have lots to learn about it.

Cloud1 2nd Dec 2009 19:06

I would not take too much notice of the Aviation Herald as it is a website full of crap - they even make a big deal over a birdstrike which is followed by a completely normal landing or a passenger requiring medical assistance on landing - they go way over the top and offer a whole new insight in to **** journalism.

cardhappyaf 3rd Dec 2009 12:10

i fly this route a lot using air france.

for me there is always turbulance at the point this happened. i dont think i have taken a flight where it hasnt happened.

i dont know what would be described as servere turbulance but certainly had some moments where i have sweated a few times....

keltic 4th Dec 2009 09:36

I have been reading Avherald, which I have to admit I hadn´t heard about it before. A bit alarming?. Overeaction?. There are some interesting comments, specially about an Iberia FA who tells that crossing the area, she never found any serious turbulence, or at least to stop the service. And someone from TAP, who says they cross continiously without major incidence.

RoyHudd 4th Dec 2009 18:59

Passenger rubbish.
 
Passengers know nothing about such things. They are blissfully unaware if a crew have adroitly steered the aircraft through a complex rash of Cb's, painting a multitude of hues of red on their skillfully utilised radar systems.

And of course, they can see nothing ahead out of their windows. Or much from the sides.

There is much nonsense written on this thread by non-pro pilots.

Nothing unusual there.

Solar 4th Dec 2009 23:12

Way to go Roy, that'l garner a lot of support from the paying customers.

iceman50 5th Dec 2009 07:32

Solar


that'l garner a lot of support from the paying customers.
That's the problem these days WE do NOT need their support. We are paid and checked to be professional enough to do our job, without people who have little knowledge of it saying "they have a right to pass judgement and comment".:ugh:

Before anyone says it, NO you do NOT pay my salary, my company does. You buy a product / service from my company. Otherwise I could say I pay the salary of whoever comments by the goods and services I purchase.

Lord Lucan 5th Dec 2009 08:31


I would not take too much notice of the Aviation Herald as it is a website full of crap - they even make a big deal over a birdstrike which is followed by a completely normal landing or a passenger requiring medical assistance on landing - they go way over the top and offer a whole new insight in to **** journalism.

I have just had a first time look at this site, and in my opinion you have it absolutely wrong. This site is not "**** journalism" it is a list of accidents and incidents, and thus of interest to professional pilots. Just because an incident does not result in a crash does not mean it is not interesting! I was impressed by the level of aviation related detail which is included in their reports. It looks like a pretty good site to me, and now have it bookmarked.

If you just want to salivate over crashes, there are plenty of places on the net to satisfy your tastes, I think.

doyll 5th Dec 2009 10:26

I joined this site to get accurate aviation information and have. The info here is more accurate then media news of same. Thanks to all who contribute to this great forum.:ok:

Razoray 6th Dec 2009 01:28

maybe pax should be able to see straight ahead........

pax can at least see what you just went through!

:sad:

Ten West 6th Dec 2009 02:57

Speaking as a non-pilot pax (Okay, I work in Flight Operations, but I'm still pax) I trust the pilots 100%. What other option do passengers have anyway once they're on board?

I can't understand these people who know nothing about aviation, pay to get on an aeroplane and then sit there quietly worrying about every little wobble or shake or bit of cloud they can see on the horizon.

I think:

The Captain is smarter than me.
The Captain gets paid an awful lot more money than me.
The Captain has been through an awful lot of training.
The Captain has worked very hard to get to sit in the pointy end.

He also has all the information at his disposal. If he's happy to operate then I'm more than happy to sit behind him and read my book.
:ok:

misd-agin 6th Dec 2009 03:30

The Captain wants to get home as much as anyone else on the airplane.

ATC Watcher 6th Dec 2009 08:03


The Captain is smarter than me.
The Captain gets paid an awful lot more money than me.
The Captain has been through an awful lot of training.
The Captain has worked very hard to get to sit in the pointy end.
This reminds me of the boards one can buy in the USA tourist shops , starting with " my wife is always right because ..."

Unfortunately, in this particular AF445 case some of the statements above did not seem to apply. Leaks and unverified rumors from another AF forum would indicate that once more someone decided to climb quite high that night despite the forecast and the history of that particular flight .
( FL380 with 196 Tons is rumored )

mm43 12th Dec 2009 03:11

ATC Watcher

Unfortunately, in this particular AF445 case some of the statements above did not seem to apply. Leaks and unverified rumors from another AF forum would indicate that once more someone decided to climb quite high that night despite the forecast and the history of that particular flight .
( FL380 with 196 Tons is rumored )
AF Corporate has minimized the incident, while various journalists have spewed forth all sorts of unsubstantiated "facts". We've had reports that the a/c was on UN873, UN741 and UN866. One report stated that the a/c was on UN741 and near waypoint DEKON! No such w/p on that airway. Another, that the a/c was 10NM from the supposed location [estimate 3° 00'N 31° 05'W] of the AF447 accident!

After a deal of study, I came to the conclusion that the a/c was on UN866 and the last squawk was received around 0238z when 254NM from MSS (Mossoro), or 18NM past MAGNO [255NM to DEKON]. Indications are that the incident occurred 12mins later at 0250z near 0° 53'S 35° 59'W. A mere 231.6°T x 375NM from the AF447 estimate mentioned above. Not 10NM as claimed by one journalist!

AF445 was out of SBGL/CIG gate at 2312z, off 2332z, vectored:-
-PCX- ~ SVD = 643NM 1H 31M [425KTS] 0103z UZ10
-SVD- ~ MSS = 466NM 1H 02M [450KTS] 0205z UW50
MSS ~ MAGNO = 236NM 0H 31M [460KTS] 0236z UN866
MAGNO ~ SSR = 018NM 0H 02M [460KTS] 0238z (last squawk)
SSR ~ ..LOC = 090NM 0H 12M [460KTS] 0250z Incident?


FL380 has been quoted, and my understanding is that UN866 is a unidirectional northbound only airway with "even" and "odd" FL's allocatible. However, there is 80 percent less traffic on UN866 compared with UN873 and it follows that FL deviations would result in 80 percent less chance of conflict, plus the advantage of all traffic moving in the same direction. UN741 adjacent to the west, is the unidirectional southbound airway. The three parallel airways mentioned are each separated by 90NM. There could have been more traffic that night on UN866 than UN873, due to the forecast ITCZ activity to the east.

Subject to a valid copy of the flight plan surfacing, I rest my case.

mm43

VH-UFO 12th Dec 2009 21:26


Speaking as a non-pilot pax (Okay, I work in Flight Operations, but I'm still pax) I trust the pilots 100%. What other option do passengers have anyway once they're on board?

I can't understand these people who know nothing about aviation, pay to get on an aeroplane and then sit there quietly worrying about every little wobble or shake or bit of cloud they can see on the horizon.

I think:

The Captain is smarter than me.
The Captain gets paid an awful lot more money than me.
The Captain has been through an awful lot of training.
The Captain has worked very hard to get to sit in the pointy end.

He also has all the information at his disposal. If he's happy to operate then I'm more than happy to sit behind him and read my book.
So you wouldnt mind flying Garuda with Mr Kohar then?

DeeJayEss 13th Dec 2009 10:51

@mm43 --> where the heck do you find that sort of information! Dude, I thought I was resourceful! Well done to you Sir, kudos, kudos.

Now, no one go and ask any journos to comment about whether the passengers of AF445 should now all be hospitalised because of the increased radiation danger from flying through the storms ...

merlinxx 13th Dec 2009 14:33

mm43
 
If verified, good call Old chap :ok:

GHOTI 13th Dec 2009 17:18

Why not Pan Pan Pan 'stead of Mayday?
 
Just wondering why Mayday is called when a Pan call would seem more suitable. Not up to speed on current SPOs on these routes, but had always considered Mayday to be in it's literal (French form) a call for help, as opposed to Pan which is a warning.
Would appreciate some enlightenment here.

mm43 13th Dec 2009 18:35

GHOTI

It's a subjective call.

MAYDAY is essentially designed to be used in "dire" situations where the craft is in imminent danger, e.g. loss of control which could ultimately lead to the loss of the craft and those on-board.

PAN is used for situations where help is urgently needed in relation to persons on-board, e.g. a medical condition requiring an urgent diversion, but the craft is not in danger.

In the case where ATC clearance is not available/obtainable and the situation is one where a deviation from your clearance is occurring or is immediately required, the use of MAYDAY is acceptable. Adherence to any known jurisdictional emergency procedures should if possible then be followed.

mm43



ChristiaanJ 13th Dec 2009 20:46

GHOTI,
Wasn't this brought up somewhere else already, with PAN not being recognised everywhere?

ATC Watcher 13th Dec 2009 22:04

Apparently from an AF source: A/C confirmed to have been at FL380, 1st level immediately above Optimum ,severe turb encountered, requested on HF to descend, no immediate reply, , crew called Mayday, (as it is planned in their company procedures) and descended to 360.

Like the AF445 and the 1996 accident (AF 747-400 above Ouagadougou) the interesting question is the Wx forecast received and the subsequent choice of route and FL .

p51guy 14th Dec 2009 00:14

PAN would not be appropriate if you were descending with no clearance because of severe turbulence through opposite direction altitudes. Mayday is for problems that need immediate vigilance even if the controllers don't hear it, other flights will. I think I would move right of course a bit if I heard that on my airway. We have demonstrated over Brazil how accurate the GPS is.

rottenray 14th Dec 2009 04:39


P51 writes:

PAN would not be appropriate if you were descending with no clearance because of severe turbulence through opposite direction altitudes. Mayday is for problems that need immediate vigilance even if the controllers don't hear it, other flights will.
Exactly. PAN is a shout for help, while MAYDAY announces to all an emergency.

Can't hold it against the crew for being more diligent in reporting.

Frankly, on that route, a few extra maydays won't be a problem - given the mystery of AF447.

Much better to have to filter through the possible "boy who cried wolf" issues and get extra data than live through another 447-style mystery.

One must look at it as a teachable moment.

We're better off if crews have a lower reporting threshold for the moment, as we'll capture more data.

Even if it does turn out that AF447 was lost due to overconfidence (not saying it was) or through a fault in the airframe/software (not saying that, either) it would be much better to have lots of reports about the conditions in the ITCZ.

Any such information can help with training, and can help with engineering.

Again, making no comment about exactly what happened to AF447 - just putting forth the idea that all reporting at this point can be helpful.

Bit of old history here... Before organized police forces, the "private" security forces (hired thugs) relied on people called town cryers.

Those folks announced the news, such as they knew it.

Personally, I think it might be worthwhile to pay a lot of attention to the data from flights through this zone. I realize it might cost a few extra bucks to download from the "quick" recorders, but perhaps that's what should be done - so that we can get metrics on "average" flights and see if there are any trends.

AF447 was clearly way outside of the expected - so we need to re-tune what we expect on these routes until we figure out what happened.
...


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