B767 American at Chicago - ground fire (Thread Tecnico)

[sigmet]

http://www.airlive.net/breaking-plane-i ... ago-ohare/

[JT8D]

Ieri era apparsa la notizia che l'evento poteva essere stato causato da un FOD in pista, le ultime evidenze parlano di Uncontained Engine Failure di origine ancora sconosciuta.

"On Oct 28th 2016 The FAA reported the aircraft blew a tyre prompting the crew to reject takeoff.

The airline reported an engine malfunction prompted the crew to reject takeoff. Seven passengers and one flight attendant received minor injuries and were taken to hospitals.

On Oct 28th 2016 The NTSB reported a tyre blew out resulting in a fire. Investigators have been dispatched on site, an investigation has been opened.

Gossip from Chicago suggested, a number of right hand main tyres burst after the aircraft hit a foreign object on the runway, debris penetrated the right hand inner fuel tank causing a substantial fuel leak and resulting fire.

On Oct 29th 2016 the NTSB reported that an examination of the right hand engine revealed the #2 stage high pressure turbine disk had failed, ejecting parts of the disk, which landed in an UPS warehouse about 2920 feet from the aircraft. So far about 90% of the disk have been recovered including another piece that was found 0.3nm from the accident site. The damage to the fuselage was limited to windows and cosmetic interior, there was no fire inside the cabin. The cause of the engine failure is not yet known. There were 20 minor injuries as result of the evacuation."

(http://avherald.com/h?article=49ffa115&opt=0)

Paolo

[sigmet]

Non e' la prima volta per un 767

Incidente molto simile ad un altro accaduto esattamente un anno fa:
http://www.ntsb.gov/_layouts/ntsb.aviat ... 4249&key=1


da ricordare inoltre quello dell US Aiways durante un run up:
http://aviation-safety.net/database/rec ... -0&lang=en

[JT8D]

Interessante. In particolare riferendosi al secondo esempio che hai portato, il problema si è verificato sempre ad un disco della HPT, provocando un uncontained failure, quindi le avarie sono molto simili tra loro e interessano lo stesso componente, pur se in stadi diversi. La motorizzazione è la stessa (CF6-80C2B2 nel caso dell'US Airways, CF6-80C2B6 nel caso dell'American l'altro giorno).

Riguardo il Dynamic International Airways, con motori diversi (P&W JT9D) sembrerebbe che il problema sia stato il distacco di un accoppiamento nella main fuel supply line tra ala e motore.

Sempre il 28 ottobre si è verificato anche questo caso a Barcellona:

http://avherald.com/h?article=4a002aab&opt=0

sempre con CF6-80C2, di cui per ora non si sa molto.

Attendiamo di conoscere maggiori info sull'evento, ma entrambi gli esempi che hai portato sono interessanti da considerare.

Paolo

[JT8D]

"On Nov 4th 2016 the NTSB reported the aircraft entered runway 28R at taxiway N5 and was accelerating for takeoff through 128 KIAS 6,550 feet past the runway 28R threshold with the engines at takeoff power, when the right hand engine failed, two seconds later the power levers were retarded at 134 KIAS and brake pressures began to increase as autobrakes activated and speedbrakes automatically extended. The aircraft came to a full stop about 25 seconds later 9,225 feet past the runway 28R threshold with a pool fire below its right hand wing fed by a fuel leak. The right hand engine's stage 2 high pressure turbine disk had fractured into at least 4 pieces, one piece went through the right hand wing, over the fuselage and into a UPS warehouse. The majority of the disk was collected and sent to Washington for lab examination, results so far show one of the fractures showed indications of fatigue cracking initiated at an internal inclusion near the forward side of the hub's inner bore.

The NTSB continued the disk at accumulated 10,984 cycles with a limit of 15,000 life cycles."

(http://avherald.com/h?article=49ffa115&opt=0)

Paolo

[Ayrton]

qui mi piacerebbe riallacciarmi ad un thread passato in cui si discuteva della V1 e della chiamata della stessa...
Qui a 128k il motore scoppia, due secondi dopo le leve vengono messe in battuta e inizia la manovra di RTO a 134k...poniamo il caso astratto che la V1 fosse stata 130k...caso limite si, ma?
Mi scuso per l'ot, mi sembrava una cosa interessante a considerare

[JT8D]

Aperto il Public Docket sull'evento da NTSB:

https://dms.ntsb.gov/pubdms/search/hitl ... etID=60058

Paolo

[JT8D]

"An internal defect in a commercial airliner engine caused an uncontained engine failure resulting in a fire and the emergency evacuation of all aboard, the National Transportation Safety Board said Tuesday.

American Airlines flight 383, a Boeing 767 bound for Miami, was on its takeoff roll at Chicago O’Hare International Airport Oct. 28, 2016, when a turbine disk in the right engine failed, sending metal fragments through a fuel tank and wing structure. The flight crew rejected the takeoff just as the jetliner approached takeoff speed and stopped the airplane on the runway. All 161 passengers and 9 crewmembers evacuated as emergency responders battled the fuel-fed fire. The airplane was damaged beyond repair. One passenger was seriously injured.

The failed turbine disk was recovered in four pieces, one of which weighed 57 pounds and was found more than a half mile from the airplane. Through extensive examination of the disk fragments at the NTSB lab in Washington investigators determined there was a subsurface defect in the disk at the time of manufacture. Because of the nature of the defect and the limits of inspection methods, the NTSB concluded the defect was likely undetectable when the disk was produced in 1997"

https://www.ntsb.gov/news/press-release ... 0130b.aspx

Paolo

[JT8D]

NTSB ha rilasciato il Final Report relativo a questo evento:

https://www.ntsb.gov/investigations/Acc ... AR1801.pdf

Riassunto anche qui:

http://avherald.com/h?article=49ffa115/0003&opt=0

Paolo