Le chemin de croix du T900 continue ...
toujours des "Details", bien sùur !
Une inspection à faire, tous les 10 vols ...
Heureusement les détecteurs de vibrations donnent l'alerte !
On ne s'était pas trompé quand il y a plus de 2ans , on a souligné que les BAR et la rigidité d'ensemble du côté turbine des moteurs T900, étaient préoccupants, ben ça continue ??
------------ De AviationWeek, l'article de Guy Norris, du 23/10 ----------------
http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_10_23_2012_p0-510006.xml
Toujours ces satanées vibrations qui continuent à faire lâcher des pièces du T900, cette foi , des joints du disk de turbine !
On comprend les inquiètudes de l'EASA
Va pour un AD annoncé, des défauts possibles au niveau de la LPT !
On espère vraiment un TXWB qui ait résolu ces PB de vibrations récurrents et qui fatiguent les moteurs !
Et quid des T1000 de la même génération, version C "Allongée au centre ??" maintenant ??
Operators of Rolls-Royce Trent 900-powered Airbus A380s have been
instructed to
inspect, and if necessary replace, parts of seals around
the low pressure turbine (LPT) following damage to an engine caused by
vibration.An airworthiness directive issued by the European
Aviation Safety Agency (EASA) says that the condition, if not corrected,
could lead to cracking developing in the engine’s LPT second stage,
“possibly resulting in an uncontained engine failure and subsequent
damage to the aircraft.” The issue, which is not related to the
oil-system problems that led to the uncontained failure of a Trent 900
on a Qantas Airways A380 in Singapore in 2010, was uncovered when debris
was found in the tailpipe of an engine that had experienced increased
vibration during a revenue flight.
The inspection revealed
the
turbine disc had lost material from part of the interstage seal, sending
parts into the downstream LPT stages.
Preliminary findings indicate
that fins on the interstage seal had “rubbed into the stage 2 honeycomb
seal, which overheated and cracked, finally resulting in releasing a
portion of the ISS (interstage seal) area of the disc.” The AD,
which is effective as of Nov. 5, says inspections must be conducted
within 10 flights if an engine health monitoring system picks up
vibration levels that exceed the preset alert limits.
In August,
EASA issued an AD calling for inspections and replacement if needed of
the Trent 900 LPT shaft and bearing housing end cover. The action
followed an in-flight turn back which resulted from the seizing up of
the low pressure system in one of the A380’s engines.
The fault was
traced to oil starvation of the bearings caused by a fracture in an oil
transfer tube. It had fractured because a support piece was missing.Et ...
http://www.casa.gov.au/wcmswr/_assets/main/lib100158/2012-0220.pdf
JPRS