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AF 447 SIGNIFICANT EVENTS. « The crews can inherit latent conditions created by people far removed in time and space from the event. ». ICAO. October 1993 : A330 certification with Rosemount Pitot probe.
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AF 447 SIGNIFICANT EVENTS AF447-significant-events
« The crews can inherit latent conditions created by people far removed in time and space from the event. » AF447-significant-events
ICAO AF447-significant-events
October 1993: A330 certification with Rosemount Pitot probe AF447-significant-events
Décember 1995 : TFU 34.13.00.005. Airbus reports Rosemount probe defects due to inadequate certification and starts Goodrich probe development. Extracts : AF447-significant-events
“STRONG CUMULO-NIMBUS (Cb) CONTAINING A HIGH DENSITY OF ICE CRYSTALS • CAN BEEN COUNTERED, PARTICULARLY IN THE INTERTROPICAL CONVERGENCE • ZONE (ITCZ). IN SUCH AN ICY AND TURBULENT ATMOSPHERE, THE A/C AIR DATA • PARAMETERS (PRESSURE DEPENDANT) MAY BE SEVERELY DEGRADED, EVEN • THOUGH THE PROBE HEATERS WORK PROPERLY. • IT HAS APPEARED THAT THE CHARACTERISTICS OF SUCH AN ENVIRONMENT COULD • EXCEED THE WEATHER SPECIFICATIONS FOR WHICH THE PITOT PROBES ARE • CURRENTLY CERTIFIED. • THE WEATHER SPECIFICATIONS (ICING/LIQUID WATER CONTENT/GUTLET SIZE) • TO WHICH THE PITOT PROBES SHALL RESIST HAVE THEREFORE BEEN UPDATED • WITH MORE STRINGENT REQUIREMENTS ON THE BASE OF THE FIELD EXPERIENCE • AND RECENT EXTENSIVE FLIGHT TESTS. • AIRBUS HAS LAUNCHED THE DEVELOPMENT OF THE FOLLOWIN MODIFICIATIONS: • DEVELOPMENT OF A NEW PITOT PROBE ABLE TO MATCH THE NEW REQUIREMENTS. • ALL FLIGHT TESTS AND WIND TUNNEL TESTS ARE NOW COMPLETED AND • SUCCESSFULL : THE CERTIFICATION OF A NEW PITOT PROBE HAS BEEN OBTAINED EARLY IN NOVEMBER 1996 (NEW PITOT PROBE : P/N 851HL MOD 44836).” AF447-significant-events
« Keep in mind that the specification references are TSO C16 and AS 393 AF447-significant-events
November 1996 : Rosemount probe replaced by Goodrich probe (Airbus mandatory) AF447-significant-events
November 1998: Rosemount probe replaced also by Sextant (Thalès) AA probe… AF447-significant-events
August 2001 : French DGAC says these 2 replacements are mandatory with AD 2001-354(B) : AF447-significant-events
“ On november 25 2002, FAA said : “The DGAC advises that operators have reported several cases of loss or fluctuation of indicated airspeed when flying through heavy precipitation or freezing weather conditions. The probable cause has been attributed to the presence of ice crystals and/or water exceeding the weather limits for which the pitot probes are currently certified. Loss or fluctuation of indicated airspeed, if not corrected, could result in inadvertent excursions outside the normal flight envelope.” « This Directive requires the installation of Pitot probes meeting more stringent qualification requirements, but... » AF447-significant-events
« …the specification references stay TSO C16 and AS 393 ! How was the Thales AA probe certified by french DGAC, taking into account Rosemount experiment ? !» AF447-significant-events
Jully 2002 : OIT SE 999.0068/02/VHR. Airbus reports Thales AA defects. Extracts : AF447-significant-events
“ THE AIM OF THIS OIT IS TO INFORM THE OPERATORS THAT SEVERAL SINGLE AISLE OPERATORS HAVE REPORTED AIRSPEED DISCREPANCY ON AIRCRAFT FITTED WITH THALES PITOT PROBES PN C16195AA.” INVESTIGATIONS CARRIED OUT SHOW THAT BURRS CAN REMAIN INTHE PITOT PROBE AFTER DRILLING OF THE DRAIN HOLES. AS A CONSEQUENCE THE BURRS COULD ASSIST THE ACCUMULATION OFEXTERNAL POLLUTION AND CONSEQUENTLY COULD BLOCK THE DRAIN HOLES.” THE CONSEQUENCE IS AN INCORRECT TOTAL PRESSURE MEASUREMENT LEADING TO AN INCORRECT AIRSPEED COMPUTATION.” AF447-significant-events
January 2005 : Thalès develops « ADELINE » research project. Extracts : AF447-significant-events
The objective of ADELINE is to develop new architectures and technologies of air data systems for implementation in new aircraft on the horizon of 2010. Actual air data equipment is composed of a large number of individual probes and pressure sensors. This equipment delivers vital parameters for the safety of the aircraft’s flight such as air speed, angle of attack and altitude. The loss of these data can cause aircraft crashes especially in case of probe icing. AF447-significant-events
August 2006 : Airbus SIL 34-084. Flushing interval is reduced from 2C to C check AF447-significant-events
« 21 months between 2 C checks ! Why did Airbus not reduce this interval any more ? » AF447-significant-events
Septembre 2007 : EASA reports Pitot probe certification ETSO C16 is obsolete. AF447-significant-events
AS393 1947 ! AF447-significant-events
« EASA says ETSO C16 is obsolete and need to be updated but they do nothing. Why ? » AF447-significant-events
« Obsolete… » AF447-significant-events
« Equipments must function properly in the full normal operating envelope of the aeroplane » AF447-significant-events
« Hazardous means a large reduction in safety margins, excessive workload for the crew, serious or fatal injuries » AF447-significant-events
September 2007 : Airbus recommends replacement of the Thales AA probe by the Thales BA probe, not mandatory. AF447-significant-events
« But one year later… » AF447-significant-events
September 2008: Airbus reports « the Thalès BA is not intended to support severe icing conditions » … AF447-significant-events
(Air France Info PNT n°5 extract) « Air France and Airbus are discussing…» AF447-significant-events
« Air France does not replace AA probes by BA probes » AF447-significant-events
Air France reports 9 precursor serious incidents between june 2008 and march 2009 (AA probes). AF447-significant-events
« One crew had reported MAYDAY on the frequency » « NO investigation by french BEA » « NO safety information by french DGAC » « Air France is still discussing with Airbus… » AF447-significant-events
A few days before AF 447 accident, Air France starts replacement of Thales AA probes by Thales BA probes. AF447-significant-events
june 1st 2009 : AF 447 accident F-GZCP (Thales AA probes equipped) AF447-significant-events
« According to french BEA, the A330 was flying at FL 350 through the ITCZ (ice cristals) . Airspeed discrepancy was reported by ACARS. » « According to EASA, inconsistent measured airspeed could be attributed to Thales AA Pitot probes faults in icing condition. » « Hum… from our point of view, you may read can beattributed… » AF447-significant-events
« The consequence should be an inadvertent excursion of the A330 outside the normal flight envelope » AF447-significant-events
«In 2002, the excursion outside the normal flight envelope was identified by french DGAC as a consequence of the loss or the fluctuation of indicated airspeed » AF447-significant-events
. 225 kts Maxi 1,7g 275 kts . 15 kts Turbulence 1,5g ISA+15 Turn * Speed in turbulence 260 kts 1G As you can see, the flight envelope is very limited * avoiding weather AF447-significant-events
« AF 447 crew had not been warned of any problem with the weather » (weather chart used by the crew) AF447-significant-events
AF447 flight plan « easy to avoid » TASIL AF447-significant-events
« He could have been warned by the CCO Air France 2 hours before reaching TASIL with that satellite view… » AF447-significant-events
(alternative routes) AF447-significant-events