Aereo passeggeri si schianta in Nigeria con 150 persone a bordo

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In letteratura ci sono parecchia casi, a memoria mi viene in mente un 747 BA che si è trovato tutti e 4 i motori spenti per ingestione di cenere, il 320 della USAirways che ha avuto un un birdstrike multiplo ed è ammarato sull'hudson o il 777 di BA rimasto senza motori in finale a causa di formazione di ghiaccio nei condotti.

Aggiungo anche il 767 Air Canada che rimase senza i due motori a causa dell'esaurimento del combustibile.
 
Aggiungo anche il 767 Air Canada che rimase senza i due motori a causa dell'esaurimento del combustibile.

Tra gli aerei che rimasero senza carburante ci sono anche l'A330 di Air Transat che fece un atterraggio di emergenza alle Azzorre, l'A310 di Hapag Lloyd che atterro' corto a Vienna e il B707 di Avianca a New York.
 
veramente una piantata in finale non ė cosi critica. questo perchė i motori sono al minimo o,quasi.

Scusa ma non mi risulta sia così. In finale l'aereo è di solito configurato con i flap al massimo quindi i motori non sono assolutamente al minimo anzi...devono spingere per compensare l'effetto dei flap. Se ti vengono a mancare i motori in una situazione del genere vai giù subito. Ricordo che nell'incidente del 777 BAW a Heathrow (ove nessuno fortunatamente morì) fu proprio la pronta azione del comandante che, una volta venuti meno i motori, retrasse i flap di una tacca (o forse due, ora non ricordo bene) per permettere all'aereo di planare giusto per i metri necessari a non atterrare sulla strada antencendente al sedime aeroportuale: fu proprio quell'azione a salvare la vita dei passeggeri e, con ogni probabilità, anche di alcune persone a terra.
 
Why Nigeria Plane Lost Power Before Crash Still Mystery


Nigeria
’s chief aviation regulator, recommended for suspension after the nation’s deadliest accident in almost 40 years, defended his record as several safety advocates said he may become a scapegoat.
“Would you please wait for the accident investigation to complete, to have seen the black boxes, before we start judging?” Harold Demuren, director general of the Nigerian Civil Aviation Authority, asked in a phone interview yesterday.
Demuren appealed for patience during the investigation into the Dana Airlines Ltd. crash on June 3. All 153 people on board and an unknown number on the ground were killed when the Boeing Co. (BA) MD-83 jetliner crashed and burst into flames in a Lagos suburb while approaching the airport on a domestic flight.
Nigeria’s aviation industry had one of the world’s worst safety records in 2006, a year after Demuren took his job. Four years later, the U.S. Federal Aviation Administration gave Africa’s largest oil producer a Category 1 rating, which allowed its domestic carriers to fly to the U.S.
“We have become one of the safest places in Africa,” Demuren said, speaking from Nigeria.
Nigeria’s Senate voted June 5 to recommend that Demuren be suspended. The minister of aviation, Princess Stella Adaeze Oduah, will convene a panel June 11 to review the nation’s aviation oversight system, according to an e-mailed press release.

Chaotic System

Demuren has come under criticism for an aviation system that he said can be chaotic at times, with flights postponed and carriers not always adhering to schedules. Part of the reason for delays, he said, was that his authority has imposed stricter safety standards that prohibit departures in bad weather.
The Flight Safety Foundation, a U.S. non-profit advocacy group, issued a statement this week calling on Nigeria’s leaders to “not compound this tragedy” by targeting Demuren.
“You can’t let a leader go down in Africa if you want to make any change,” Bill Voss, president of the Alexandria, Virginia-based foundation, said in an interview June 6.
Tony Tyler, director general and CEO of the International Air Transport Association, a Geneva-based trade group, also backed Demuren.
“Safety is a constant challenge everywhere in the world,” Tyler said in a statement. “In Nigeria, as elsewhere, this important work must continue without political interference.”

Safety Improvements


In 2005 and 2006, airlines in Nigeria had three fatal crashes and three others serious enough to destroy the aircraft, according to the AviationSafetyNetwork, a Netherlands-based website that tracks aviation safety statistics. Those accidents killed a total of 322.
From that stretch until the Dana Air crash, there was one accident that claimed three lives, according to the group’s data.
A plane operated by a Nigerian cargo airline, Allied Air, skidded off a runway in Accra-Kotoka Airport in Ghana on June 2, striking a van on an adjacent road, according to the safety network’s website. The collision killed 12 people in the van.
The Dana flight crew’s final radio broadcasts included “Mayday. Losing two engines” and “Throttle not responding. Not responding,” Demuren said in the interview, emphasizing he was speaking from memory.
The pilot didn’t mention hitting birds, which has caused simultaneous loss of power in two engines in other incidents, or any other reason for the failures, he said.
The crash-proof recorders on the jetliner, known as black boxes, have been found and will be flown to the U.S. for analysis by the Washington-based National Transportation Safety Board, which is assisting in the investigation, Demuren said.

Fueling, Maintenance


The jet took on what Demuren characterized as a routine fuel load before departing Abuja, the capital. The crew added 12,125 pounds (5,500 kilos) of jet fuel before the fatal flight, he said.
Other aircraft had refueled in Abuja without reports of engine failure, which suggests the fuel wasn’t contaminated, he said.
Nigeria imposes maintenance requirements similar to those in the U.S. and Europe. Dana had performed maintenance in a facility in Istanbul, he said.
Investigators combing the charred wreckage, which was partially lodged in an apartment building, have found all major pieces of the plane, he said. It remained pointed toward the airport when it struck the ground a few miles short of the runway, he said.

Engine Failures


Accident investigators can tell from the pattern of damage in engines whether they were under power when they struck the ground. No determination has been made on the Dana engines, Demuren said.
Today’s jet engines are so reliable that it’s very unlikely two would fail at once, John Cox, a former airline pilot who is a consultant at Washington-based Safety Operating Systems, said in an interview.
Pilots have inadvertently closed fuel switches or shut engines down, mechanics have botched repairs on multiple engines, and engines have quit during extreme maneuvers, according to files at the U.S. NTSB and the AviationSafetyNetwork.

fonte: http://www.bloomberg.com/news/2012-...ne-lost-power-before-crash-still-mystery.html
 
Resti di uccelli in uno dei motori...Intanto licenza sospesa

Des débris d’un ou plusieurs oiseaux ont été retrouvés dans un des moteurs du McDonnell-Douglas MD-83 de la compagnie Dana Air, qui s’est crashé le 2 juin dernier dans la banlieue de Lagos au Nigeria, a révélé l’un des dirigeants de Dana Air. L’enquête continue.

«*Je ne sais pas ce qui a pu provoqué l’accident, a affirmé ce dimanche 10 juin à la télévision nigériane un haut responsable de la compagnie, le capitaine Oscar Wason, mais ce matin nous avons trouvé les restes d’oiseaux dans un des moteurs,*» en ajoutant que les oiseaux sont légion dans la région et que leur passage sur la trajectoire de l’avion aurait pu être la cause de « la perte de puissance*» des moteurs.

Seule chose certaine, les pilotes ont signalé un problème de réacteur à une quinzaine de kilomètres de l’aéroport de Lagos et ils ont envoyé un SOS pour un atterrissage d’urgence, mais sans parvenir à destination. L’appareil s’écrasera à 2 km de la piste dans un quartier très peuplée, détruisant un immeuble de deux étages. Les 154 occupants plus un grand nombre de personnes au sol sont décédés. Le président du Nigeriaa décrété trois jours de deuil national pour ce crash majeur dans l’histoire du pays.

L’explication d’un choc aviaire est plausible car les oiseaux sont en effet un fléau pour l’aviation. On se rappellera qu’un Airbus A320 de la compagnie US Airways, s’était posé en catastrophe sans faire aucune victime en janvier 2009 sur le fleuve Hudson à New York après qu’une collision avec des oiseaux au décollage avaient endommagé ses réacteurs. Mais dans le cas de Dana Air, l’enquête continue alors qu’une suspicion s’est fait jour sur la maintenance McDonnell-Douglas MD-83, âgé de 22 ans. En attendant les résultats de l’enquête, la licence de la compagnie aérienne Dana Air a été suspendue.
 
Nigeria's Accident Investigation Bureau (NAIB) have released their preliminary report reporting the aircraft was on its 4th leg of the day on round trips between Lagos and Abuja.

Dana Air's MD-83 5N-RAM was on final approach to Lagos' runway 18R when the crew reported total loss of power.

The cockpit voice recorder, containing 31 minutes of recordings, revealed the crew was in a discussion about a non-normal condition regarding throttle lever position and engine EPR indications, although the crew was not concerned at that point 31 minutes prior to the accident, that the safe continuation of the flight would be affected by this condition. The crew monitored this condition and became increasingly concerned during the descent towards Lagos.

The crew reported descending through 18,100 feet at 15:30L and descending through 7700 feet at 15:40L. Between 15:37L and 15:41L the crew was engaged in configuring the aircraft for landing deploying flaps and landing gear. At 15:41:16 the first officer queried "Both engines coming up?" and the captain replied "negative". The crew subsequently declared emergency at 15:42:10L reporting "dual engine failure ... negative response from throttle." The crew subsequently deployed flaps further while continuing the approach and discussing an alternative landing on runway 18L.

At 15:42:45L the captain reported the runway in sight and instructed the first officer to clean the flaps and retract the landing gear.

At 15:43:27 the captain told the first officer "we just lost
everything, we lost an engine. I lost both engines". During the next 25 seconds the crew attempted to relight both engines, the aircraft however crashed about 5.8nm north of the threshold of runway 18R approximately on the extended runway center line.

All 147 passengers and 6 crew on the aircraft and 10 people on the ground were killed in the crash.

The flight data recorder tape was consumed by post crash fire.

The captain (55, ATPL, 18,116 hours total experience, 7,461 hours on type) had been employed with Dana Air since Mar 14th 2012, the first officer (34, CPL, 1,143 hours total, 808 hours on type) had been hired by Dana Air in January 2011.

The left hand engine had accumulated 54,322 hours in 30,933 cycles, the right hand engine accumulated 26,025 hours in 12,466 cycles.

The aircraft had last undergone maintenance on Jun 1st 2012. There were no entries in the technical logs regarding any abnormal condition of the engines.

The aircraft had loaded 8,000 lbs of fuel in Abuja and according to logs had 26,000 lbs of fuel on board thereafter. Analysis of the fuel showed no contamination.

The investigation is on-going.

fonte: avherald.com
 
Pero' purtroppo il FDR e' andato completamente distrutto e gli investigatori non sono riusciti ad ottenere informazioni. Non sara' facile capire la causa di un double flame out, anche perche la fuel contamination e' stata esclusa. E dato che sembra che i problemi con i motori siamo iniziati circa mezz'ora prima dell'incidente, anche un bird strike e' improbabile. Mi ricordo di un paio di casi di DC9/MD80 (ad esempio quello di SAS) che hanno avuto un double flame out a causa dell'ingestione di ghiaccio, ma qui lo escluderei, così come il ghiacciamento delle linee del carburante (che causarono l'incidente del 777 di BA a LHR).

http://www.flightglobal.com/news/ar...-dana-md-83-dual-engine-failure-probe-374357/
 
E' stato pubblicato il report di un incidente avvenuto ad un CRJ-200 della Air Nostrum il 24/02/2009. Anche in questo caso l'aereo aveva subito lo spegnimento simultaneo dei due motori. Per chi conosce tecnicamente i due aerei, e' possibile un simile scenario sull'MD-83? In entrambi i casi i velivoli si preparavano all'atterraggio.

http://avherald.com/h?article=41599b79/0001&opt=0

No, sul Md80 i motori li spegni (procedura normale) portando le fuel shut off levers in posizione chiuso, devi premere un "nottolino" al centro caricato a molla in posizione di blocco e poi portare la leva giu' , proprio per evitare che la leva possa essere per errore o fortuitamente portata in posizione di shut off (ha quindi un blocco meccanico quando tu la porti su on.
Le manette non hanno una posizione che "tagli" l'alimentazione ai motori. Tra l'altro lo Md ha un dispositivo che si chiama Approach idle che in approach e in finale tiene il minimo dei motori piu' alto di quello a terra , per consentire una piu' rapida accelerazione in caso di go around.
Comunque da quello che si evince dal CVR, il crew in volo aveva chiaramente problemi di sfasamento manette e di <epr indications, una causa o sintomo dell'altra.
 
On Jun 3rd 2014 The Nigerian AIB released their second preliminary statement reporting that the investigation is ongoing, an engine tear down is being conducted with the special focus on the engines' fuel systems.

The AIB reported that while these works were under way another similiar incident happened on another Dana Air MD-83, see Incident: Dana MD83 near Port Harcourt on Oct 6th 2013, engine shut down in flight by itself.

The AIB stated: "Investigative reviews of the engine teardown especially the fuel systems are still ongoing. During this process a similar incident occurred on another MD 83 aircraft of Dana Airlines on the 6th of October, 2013. AIB is currently investigating in-depth systematic and safety issues associated with this second incident vis-à-vis, the crashed sister ship, 5N-RAM. The safety actions adopted by the operator to redress the findings are being monitored and analyzed."

The AIB reported that three interim safety recommendations have been issued and accepted as result of the investigation so far.

http://aib.gov.ng/reports/2nd INTERIM STATEMENT ON DANA AIRLINES.pdf

http://www.avherald.com/h?article=4508fb60/0003&opt=0

Fonte: avherald.com