A E R O H A B I T A T Centro Studi

Incidenti aerei

Fiumicino, ancora un atterraggio Airbus 320 con semicarrello

Interrogativi sull'impianto carrello Airbus 320. Se all'Airbus 320 della Wizz Air dello scorso 8 giugno il semicarrello bloccato up era stato quello sinistro nel caso dell'atterraggio di emergenza avvenuto intorno alle 21.00 di domenica 29 settembre - sulla stessa pista 16 sinistra di Fiumicino, al volo Airbus 320 Alitalia 063, è stato il semicarrello destro.

La nota informativa ANSV, tuttavia, sostiene "di aver aperto un’inchiesta di sicurezza sull’evento occorso intorno alle 21.00 locali di domenica 29 settembre, sull’aeroporto di Roma Fiumicino, all’A320 marche EI-EIB, che, proveniente da Madrid, è atterrato senza carrello". Senza carrello. La questione verrà sicuramente verificata e sarà chiarito questo primo aspetto sulla causa e portata dell'avaria tecnica.

In entrambi i casi la procedura di preparazione all'atterraggio di emergenza è avvenuta - si deduce - dopo aver espletato le rituali fasi di verifica dell'avaria all'apparato dei carrelli: in estensione automatica e, successivamente con la tecnica manuale.

Tra i 151 passeggeri a bordo, probabilmente, qualche panico, ma solo una decina di contusi. Il velivolo è stato rimosso dalla posizione finale con una gru speciale nella nottata del lunedì mattina.

Commenti e considerazioni di Aerohabitat saranno riportati nelle prossime giornate. Al momento è opportuno segnalare uno stralcio di quanto riportato dal sito www.avherald.com relativo all'incidente della Wizz air e i riscontri riportati dall'EASA e dall'ANSV sul sistema carrello di questa tipologia di flotta..

"On Jun 25th 2013 EASA (European Aviation Safety Agency) released an Emergency Airworthiness Directive requiring operators of A318/A319/A320/A321 aircraft to determine the configuration of their aircraft and identify part numbers of the left hand and right hand Landing Gear Control Interface Unit as well as the part numbers of the gear door actuators within the first 800 flight cycles of the aircraft or within 14 days (whichever is later). If those part numbers are found listed in the EAD although with all current airworthiness directives applied the door opening sequence is to be examined within 8 days or 5 flight cycles (whichever is later). If a discrepancy is found, the gear door actuator is to be replaced. EASA reasoned: "Some operators reported slow operation of the main landing gear (MLG) door opening/closing sequence, leading to the generation of Centralized Fault Display System (CFDS) messages/ECAM warnings during the landing gear retraction or extension sequence. Investigations showed that the damping ring and associated retaining ring of the MLG door actuator deteriorate. The resultant debris increases the friction inside the actuator which can be sufficiently high to restrict opening of the MLG door by gravity, during operation of the landing gear alternate (free-fall) extension system. This condition, if not detected and corrected, could prevent the full extension and/or down-locking of the MLG, possibly resulting in MLG collapse during landing and consequent damage to the aeroplane and injury to occupants". EASA reported, that following a "recent occurrence with a gear extension problem" Airbus detected in additional analysis that a number of expected specific messages may not be generated in a combination of specific parts which renders repetitive checks mandated by an earlier airworthiness directive not effective.On Jul 30th 2013 Italy's ANSV released a number of safety recommendations to Airbus and EASA arguing, that the EAD released by EASA on Jun 25th 2013 was insufficient to address the issue at hand. The ANSV pointed out, that the accidents of HA-LWM and N816UA, see Accident: United Airlines A319 at Newark on Jan 10th 2010, right main gear did not deploy are "fully coherent". The ANSV reported that the left main gear entangled with the gear door which prevented any corrective action to get the gear extended. Debris was found in the dampening housing, presumable from a retaining ring, a damping ring and spiralox. This condition led to the gear door actuator not moving until the pressure had increased to about 300psi, then jolted but did not fully extend, several more small jolts followed, however the actuator never fully extended until the test was aborted at 1000psi. The actuator had accumulated 5386 flight hours in 2560 cycles and had been installed as new on Feb 20th 2012. The ANSV also reported that following the second re-cycle of the normal landing gear (select gear up, then down again) the crew waited 52 seconds with the landing gear lever remaining in the down position before the gravity extension sequence was initiated, the manual however requires a minimum time of 2 minutes." 30 settembre 2013

data inserimento: Lunedì 30 Settembre 2013

Segnala su: