I’m now pretty sure that one of the best techniques to be used to analyse the aviation crashes is to think to the “deadly precedents”.
On Aug 23 I provided in this article Spanair 5022: a video doesn’t show any explosion. Did the MD82 stall before hitting the ground? my opinion about the Spanair 5022 crash that had occurred 3 days before. This is an excerpt of what I wrote:
“In my opinion, according to the few details already available and to what the witnesses recounted, the cause of the stall could be that slats and flaps were not properly positioned for departure. Why? Simply, because something similar happened at least twice in the history of aviation. Both Northwest 285 from Detroit on 16 Aug. 1987 and Delta 1141 taking off from Dallas Fort Worth on 31 Aug. 1988 crashed in similar accidents because the crew had not ensured that the flaps and slats were properly positioned for take-off. Even if there’s a checklist and various warnings designed to alert the crew if the flaps and slats are not correctly set before take off, it is possible that the system wasn’t working or the crew did not take care of the warnings or they were distracted by the first attempted departure. It must be remembered that the JK5022 left the gate at 13:05LT and returned to the ramp due to a technical problem at 13:42LT and then departed again at 14:25LT. The return to the ramp could have resulted in a checklist being discontinued and not repeated again later, when the aircraft was departing again with 1 hour of delay”.
Now just read the following article published today by the BBC news site. It was written 4 weeks later and according to it, the preliminary report draws more or less the same scenario I had hypothesized. Flaps not configured for take-off. This is important for one reason: each time an aviation accident occurs, just think to the precedents, they might immediately point at the right path to the root cause of the crash.
Wing flap ‘problem’ on Spain jet
The wing flaps on a plane that crashed in Madrid last month were not open properly at take-off, a draft preliminary report has concluded.
Investigators found that the pilots were unaware of the problem because a cockpit warning alarm did not go off, leading Spanish newspapers reported.
The Spanair plane plunged to the ground shortly after take-off, killing 154 people on board.
It was the deadliest air crash in Spain in 25 years.
Investigations into the crash are continuing, with no firm conclusions yet made about whether the disaster was the result of technical fault or human error.
Cockpit recordings
The MD-82 jet, which was preparing to fly to Las Palmas in the Canary Islands, had aborted a previous take-off attempt before it crashed.
In my experience an accident doesn’t happen for a single reason
Alfredo Perez Rubalcaba
Spanish Interior MinisterThe draft report of the investigating committee, leaked to Spanish newspapers, details how the aircraft crashed when it attempted to take off following a brief stop for technicians to correct a fault in a temperature gauge.
The pilots had detected the high temperature as they readied the plane for take-off, having already deployed the wing flaps, the plane’s black box recorder showed. They aborted the take-off to get the temperature gauge looked at by technicians, the draft report says.
By the time the plane resumed its position on the runway, the flaps – which make it easier for aircraft to get off the ground at take-off speeds – had been retracted, data from the black box is said to show.
The MD-82 plane is equipped with sensors intended to warn pilots whether flaps are correctly deployed before take-off.
However, the draft report suggests no warning signal sounded in the cockpit before the pilots accelerated the plane down the runway for the ill-fated take-off attempt.
Deadly precedent
The draft report said that Spanair did not rigorously follow advice from the plane’s manufacturers to check the flap deployment warning signal.
Following an MD-82 crash in the US city of Detroit in 1987, which killed 154 people, McDonnell-Douglas (now part of Boeing) advised that flap and slats indicator systems be checked before each flight.
However, Spanair only carried out checks on the system before the first flight of each day or when the pilot and co-pilot was changed, the draft report said.
The pair in control of the plane had already taken it from Barcelona to Madrid on the morning of the accident without incident, and were not under orders to check the systems before beginning their next flight, the draft report said.
Investigators have not released any official statement on the disaster, and Spanish Interior Minister Alfredo Perez Rubalcaba told Spanish TV the government would not comment until the investigation had been completed.
“In my experience an accident doesn’t happen for a single reason,” he said.
“We are going to wait for the report to be finished to find out what happened because there are many theories,” Mr Rubalcaba added.
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/world/europe/7618627.stmPublished: 2008/09/16 14:32:17 GMT
© BBC MMVIII
