Bonsoir !
Une histoire de "Multi Bird Strike" à Orlando !
Pour Virgin Atlantic, un A333 T700 !
Vu sur le AvHerald !
Bon, pas de vide vite (En option, sic!) des réservoirs, sur un aussi grosnavion ... hum !
Noté cette info du AAIB, apportée en commentaire !
Comme quoi, le manque de pression d'huile a provoqué le shut down du moteur 1, assertion avérée fausse, c'est le niveau de vibrations qui a occasionné cette indication de pression d'huile en cascade !
Bon, vu qu'ils ont pris un canard dans chaque moteur ... on pouvait éventuellement retrouver des "fausses" pressions d'huile à zéro des 2 côtés si le 2 avait vibré autant que le 1 après l'impact ...
Alors, il fallait éteindre les 2 suivant cette logique ??
Des indications "Biaisées" pas du tout dans le sens de la sécurité sur les T700, surtout dans ce type d'accident ! Une copie à revoir qq part, et sans attendre qu' Airbus s'y intéresse ...
(On attend toujours des modifs pour pallier aux cirque instrumental / Calculateurs / Alarmes / Resets, qui a conduit AF 447 au plongeon fatal )
Du AV Herald !
http://avherald.com/h?article=45c7d5a1&opt=0
By Simon Hradecky, created Friday, Sep 13th 2013 16:33Z, last updated Friday, Sep 13th 2013 16:33Z
The British AAIB released their [url=http://www.aaib.gov.uk/cms_resources.cfm?file=/Airbus A330-343, G-VKSS 09-13.pdf]Bulletin[/url] reporting the aircraft was climbing through 530 feet AGL out of Orlando's runway 35L when multiple birds impacted the aircraft, one hitting the nose causing an extremely loud noise causing alarm to the crew. The left hand engine's oil pressure indication dropped to zero prompting the shut down of the engine. In addition the radome and the right hand engine received damage. The aircraft returned to runway 36R for a safe single engine landing.
The flight data recorder revealed that immediately following bird impact at about 530 feet AGL the left hand engine's N1 vibrations rose from 0.4 to 10 (maximum) units, the right hand engine's N1 vibrations increased from 0.2 to 1.8 units.
The AAIB complained that although the operator had procedures in place to secure the cockpit voice recorder the same procedure did not apply to the flight data recorder which permitted the FDR to operate for 20 more hours before download resulting in most of the incident flight being overwritten.
The investigation determined there was nothing wrong with the left hand engine's oil system, the oil pressure was overwritten with a zero value and the engine's electronic control locked at overwriting the correct engine oil pressure values if the oil pump's failure detect logic detects negative differential pressure between 10 and 30 psi at both transducers within 3 seconds. The EEC lock would be lifted only after engine shut down thus appearing the engine oil pressure at 0 even after the oil pump recovered.The engine manufacturer detected a condition in which increased engine vibrations could trigger the engine oil pump failure detection and thus cause a zero engine oil pressure indication persisting to engine shut down.
The AAIB reported debris recovered from the engines was analyzed and it was determined the birds were probably
ring necked ducks of about 1.5 to 2 lbs in weight, each engine had ingested one bird.The damaged fan blades as well as the left engine's nose cowl were replaced, the aircraft subsequently ferried to Great Britain where the left hand engine was replaced. Analysis of the engine after removal confirmed that the pressure transducer oil supply lines
were secured and routed correctly.
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par Beochien Lun 2 Sep 2013 - 18:25
