Eisenbach From Austria, joined Mar 2001, 138 posts, RR: 0 Posted (5 years 8 months 2 weeks 6 days 3 hours ago) and read 4709 times:
Spanair crash result of human, technical error
Mon Aug 17, 2009 11:20am EDT
MADRID (Reuters) - A systems failure and pilots' error combined to cause the crash of the Spanair jetliner that killed 154 people in Madrid last year, concluded a preliminary report released Monday.
Spanair MD82's flaps and slats were not extended as the aircraft was preparing for takeoff, but this was not noticed during the pilots' routine pre-departure check and the automatic on-board system did not alert the error, Spain's Civil Aviation Accidents Commission said in its report.
"The aircraft had the standard procedures and check lists in force ... which included the selection and confirmation of the correct configuration for takeoff," the report said.
"The pilots used these procedures as a reference, but for some reason -- whether an interruption from the aircraft's first return to the terminal due to a mechanical problem, pressure due to time delays or faults in the cabin crew's work methods --, these were not strictly followed," it added.
The Canary Island-bound flight shot off the runway into a ravine on takeoff and burst into flames on Aug 20, 2008. It was Spain's worst air crash in 25 years. Eighteen people survived.
The Commission also made seven recommendations to improve international air safety which will be sent to the European Air Safety Agency, the International Civil Aviation Organization, and the Federal Aviation Administration in the United States.
The recommendations include pilots verifying the aircraft's take-off weight (TOW) before each flight rather than just the first of the day and a request to Boeing to review its TOW systems.
The MD-80 family is manufactured by McDonnell Douglas, which is now part of Boeing Co. Spanair is owned by Catalan investors and Scandanavia's SAS.
The Commission also recommended an annual international aviation conference to revise check lists, crew training and improvements in work methods to ensure that crews correctly configure their aircraft before takeoff and landing.
(Reporting by Teresa Larraz; Writing by Tracy Rucinski; Editing by Jon Loades-Carter)
R2rho From Spain, joined Feb 2007, 2982 posts, RR: 1
Reply 6, posted (5 years 8 months 2 weeks 5 days 5 hours ago) and read 3578 times:
Quoting Eisenbach (Reply 1): It's not clear for me, if this is a "second" preliminary report (see also Preliminary Report On Spanair Crash Released (by PlaneInsomniac Oct 9 2008 in Civil Aviation)) or the actual report.
This is the second preliminary report, not the final one.
Careful with translations from other sources...specially if they are translated from Spanish news sources (themselves often an interpretation of the report) and not the report itself.
I'll try to sum up a the most interesting things that I could pick up from the report itself (feel free to help me out):
- flaps and slats were not deployed during take off, this is the main reason for the crash
- due to RAT probe overheat (its anti-ice heating was operating on ground although it shouldn't), the corresponding CB was pulled by mechanic to deactivate the heating. The fix was accepted by pilot and a/c was dispatched.
- The relay R2-5 associated to the deactivated RAT probe heating, also powers the TOWS.
- TOWS did not function during the take off run
- The RAT probe overheat and non-functioning of the TOWS could be related to a malfunctioning of relay R2-5.
- Further investigation of the effects of R2-5 malfunctioning on the TOWS is recommended
- The disassembly of the R2-5 sought by the commission has been blocked [by a judge]
- The NTSB recently performed a simulation of an R2-5 malfunctioning on an MD-88. There was no clear way for flight crew to determine from this that TOWS was inop. Therefore it is very likely that neither maintenance nor flight crew of Spanair were aware of TOWS being inop [and remember that TOWS is a NO GO item].
- There was improper following of SOP's and checklists. In particular, the FO called out flaps position 11deg even though they were in fact retracted - leading to believe that no real verification of instruments was performed
- The crew was likely under pressure due to the previous return to gate and accumulated delay.
- There were interruptions that hindered the correct execution of the checklists
- Repeated references are made throughout the document to the crashes of the NW MD-82 in 1987 and DL 727 in DFW 1988
The recommendations and interpretations made by the commission are also interesting:
- Maintenance & checks of R2-5 are currently performed "on condition". It is recommended to define a maintenance program for this component.
- There is an inconsistency between the TOWS being only considered as a back-up (and therefore non essential) system in terms of certification, and it being a NO GO item on MMEL. Being only a back-up system, redundancy is not built into it. The commission recommends that TOWS be considered an essential system.
- The investigation concludes that a single failure in R2-5 can cause TOWS to be inop, without flight crew being aware of this.
- It is recommended to hold an international conference on design of checklists and flight deck procedures, and to compile the conclusions from all previous studies on this matter.
Spacecadet From United States of America, joined Sep 2001, 3823 posts, RR: 11
Reply 8, posted (5 years 8 months 2 weeks 4 days 23 hours ago) and read 3232 times:
Quoting R2rho (Reply 6): In particular, the FO called out flaps position 11deg even though they were in fact retracted - leading to believe that no real verification of instruments was performed
There is a term for this that I can't remember right now - this is a psychological thing that anyone who is an expert in human performance factors would know (obviously I am not). But you get so conditioned to seeing things a certain way that you just say things out of habit. I think, based on past accidents in which similar things happened, that he probably *did* look at the instruments, but called out 11 degrees anyway because that's what he expected to see. This exact thing has happened before.
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