Thread: AF447
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Old 22nd Jun 2009, 14:02   #2154 (permalink)
Join Date: Jan 2001
Location: France
Posts: 111
Internal AF document 18-06

This is the English traduction of an Air France internal document addressed to Cockpit Crew dated 18/06/09 that you can find here : (may be elsewhere I don't know)

Les dossiers noirs du transport aérien

Scroll down to 21.06.2009
or direct link :


It's an automated translation plus some personal adjustments.

Roissy, On June 18, 2009

On June 15, a point on the inquiry was made by the Management of the safety of the company in front of executives PN of the Air Operations. This "N°5" information" recapitulates all the points approached at the time of this presentation.

The accident of AF447 took place in the international water; this is thus the State where the aircraft is registered that leads the technical inquiry. Four working groups were made to this end by the Bureau d'Enquêtes et d'Analyses. Air France contributes to this investigation in bringing its expertise to work with these groups of which each members is engaged to respect the confidentiality of information.
Only the BEA is authorized to communicate on the progress of the inquiry. It will publish a preliminary report before the the 30th of June.
In parallel to the technical inquiry and in accordance with the French Right, a judicial enquiry is carried out by the GTA (Gendarmerie du Transport Aérien) under control of an instruction judge of the Court of Paris.
The rules specific to the company envisages in addition the installation of an internal inquiry. For this reason the Head office designated 5 permanent members including two flight crew staff representatives.
Finally 2 other investigations will be led at the initiative of the CHSCT PNT and PNC.


At the time of the accident the plane was leaving a zone of convection related to intertropical convergence. The satellite photos diffused to date show clouds spreading out at high-altitude, but these photographies do not indicate directly the position of the stormy cells that the crews of different companies flying on this road met. A complementary work of analyses is in progress.
The main informations that we have about the plane result from automatic maintenance messages.
These messages are embodied in the information transmitted by the plane without intervention of the crew to alow maintenance teams to prepare the interventions upon the arrival of the plane. These messages are not easily exploitable for an investigation and cannot replace data from CVR (Cockpit Voice Recorder) and DFDR (Digital Flight Dated Recorder).
More particularly, the format of the messages and logics of transmission do not allow to reconstitute with certainty the chronology of appearance of the anomalies in the cockpit.

The majority of these messages are the consequence of the anomalies and the inconsistencies of aerodynamic speeds; they were detected by the flight control calculators and the automatic pilot. Among these one can be quoted:
The loss of characteristic speeds
The passage in secondary law of flight (Alternate Law)
These associated anomalies and their consequences are tested during the certification of the plane; this allows to guarantee that the plane remains controllable in this situation.
All of these messages and their significance will be very certaily published in the preliminary report of the BEA.
At this stage, nothing in these messages allows to establish:
- A loss of power supply,
- A loss of the screens of piloting (PFD and Stand-by horizon),
- A faulty operation of the ADIRU which could have involved an incident of the type of which Qantas company knew recently.

Only one certainty: the sequence of the messages does not allow to explain the accident by itself.


Many erroneous assertions were advanced in connection with the anemometric probes equipping the Airbus fleet. We present to you in chronological order a summary of the reports and especially of the actions carried out by the company since 2001.

August 2001:

Following fluctuations and/or losses of the indications of the aerodynamic speed on A330 and A340 reported by certain companies, the DGAC publishes an “Airworthiness Directive” (AD) by plane type, to impose the replacement of the probes of Pitot ROSEMOUNT P/N 0851GR, either by probes GOODRICH P/N 0851HL, or by SEXTANT (THALÈS) P/N C16195-AA; this operation having to be finished before the 31 December 2003.
Indeed, the official services allot these events to the presence of crystals of ice and/or of quantities of water which exceeds the specifications of the probes Pitot ROSEMOUNT P/N 0851GR. In accordance with the “Airworthiness Directive”, the model SEXTANT (THALÈS) P/N C16195-AA is installed on the Air France A340 fleet ; as from December 2001, Air France receives its first A330 which is origin-equipped of the probes SEXTANT (THALÈS) P/N C16195-AA. No event of this type will be reported on Air France A330 and A340 until May 2008.

September 2007:

Airbus emits technical notes (Service bulletins or SB) which recommend, without being mandatory and outside all context affecting the navigability of the planes, the replacement of the probes THALÈS P/N C16195-AA installed on fleets A320/A330/A340 by new model probes THALÈS P/N C16195-BA.
It is indicated that this model improves the behaviour of the probe by limiting the consequences of water ingestion by strong rains and by reducing the risk of icing. After analysis, the Air France technical teams decide to launch this modification on the A320 fleet which has incidents with losses of speed indications at low altitude in case of strong rains. They decide to replace probes on A330/A340 by the new models only in the event of failure, the A330/A340 fleet having then no incidents with loss of speed informations.

May - August 2008:

A first incident of icing of the probes occurs on a Air France A340 with temporary loss of speed indications; followed by a second incident in July 2008 and then of 3 incidents in August 2008, all on A340. Airbus is immediately questioned on the origin of these incidents and to the measures allowing to cure it.

September and October 2008:

Many exchanges with the Airbus technical teams take place. An exploitation incident is recorded in September and one in October 2008. In six months, 7 incidents were thus recorded, when no incident of this kind had been reported before.
Airbus answers that:
o The supposed origin of these incidents is a icing by crystal formation in the probes of velocity measurement,
o The new model THALÈS P/N C16195-BA was not conceived to answer the problem of icing and thus should not bring significant improvement with this problem,
o The probes installed are in conformity and even exceed the lawful requirements in term of airworthiness and of safety of the flights.

November 2008:

Following various follow-up from Air France technical services, Airbus corrects its September 2007 technical notes in a dated November 12, 2008 edition that withdraws any mention of a contribution of the probe THALÈS P/N C16195-BA improved resistance to icing.
On 24 November2008 a meeting between the technical directions of Air France and Airbus discusses lengthly of the incidents with loss of speed informations. Air France requires that a technical solution be quickly brought to solve these incidents. Airbus confirms again that the origin of these incidents is an icing of the probes, that the last model THALÈS P/N C16195-BA does not treat of the subject and that the probes installed are in conformity with the airworthiness requirements and safety of the flights.

February 2009:

Facing our insistence to find a solution, wind-tunnel tests are undertaken by Thalès and Airbus on the behavior of the probe THALÈS P/N C16195-BA.

March 2009:

At the end of March 2009, two new incidents of exploitation are recorded of which a first on A330. That brings the total number of incident to 9, including 8 on A340 and one on A330.
Airbus, again requested on several occasions, answers by confirming the presumption of icing of probes and refers to a procedure of maintenance and checking of the probes.

April 2009:

In a letter of April 15, 2009, Airbus informs of a new element: the probe THALÈS P/N C16195-BA does not have vocation to answer the problem of icing of the probes, but the tests carried out by Thalès show a behavior definitely better than that of the former model. Taking into account the limitations of the wind tunnel tests, Airbus suggests an experimentation on Air France planes to check if an improvement is confirmed in real situation. Without awaiting this experimentation, Air France decides to immediately extend this measure to its entire long-distance Airbus A330/A340 fleet and to replace the totality of the probes speed. One internal technical document launching the modification is established dated April 27, 2009. The beginning of the planes modification is planned as of reception of the parts, at a rate of several planes per week, from June 1.

May 2009:

Air France requires THALÈS to accelerate the delivery schedule of the probes. Those are delivered starting May 26, 2009 at a rate of 12 tubes of Pitot per week. The program thus could be accelerated.

Since the accident:

Without prejudging of a link between the anemometric probes and the inconsistencies in the indications of speeds presented to the pilots, Air France has decided to accelerate its plan of replacement of the probes THALÈS P/N C16195-AA on the fleet Airbus. Since last June 12, all A320,A330,A340 Airbus, in exploitation within Air France are equipped with the probes of last generation THALÈS P/N C16195-BA.
Nevertheless in an information bulletin published on June 8, Airbus confirms that the Airbus world fleet can be exploited with one of the 3 types of anemometric probes which equips world fleet, namely THALÈS P/N C16195-AA, THALÈS P/N C16195-BA and GOODRICH P/N 0851HL.


We intend to recall that any step of prevention imposes three requirements;
- a requirement for transparency,
- a requirement for reactivity,
- and a requirement of pro-activity.

Whatever the circumstances, it is advisable to proceed in this way.
This is why, we have decided to keep you regularly informed of the state of advance of the inquiry and this, in an agreement with the BEA that remains the only one in charge of the communication of the factual elements.

In addition, we named two staff representatives within the Internal Commission
- Mrs L G for Commercial flight crew
- Mr O R for the Technical Flight crew.
This commission reserves the right to raise recommendations constantly if it feels it need.

2 names deleted.
PNT : Personnel Navigant Technique (Cockpit Crew)
PNC : Personnel Navigant de Cabine (Cabin Crew)
DGAC: Direction de l'Aviation Civile
CHSCT Comité d'Hygiène, de Sécurié et des Conditions de Travail
The members of the CHSCT are elected Unions members. CHSCT is competent for all matters related to the security, hygiene and work conditions of the employees in a given society.

My own comments if you allow:
This document is an internal one but the fact that some terms such as CVR or DFDR are translated in "plain" language (or even the GTA acronym) indicates 1/ That the AF PNT is really stupid or 2/ May be this document is intended for the PNT but also for the entire world. And written knowing that it might leak out. In this case who is the Charming and who is the Villain?
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