PPRuNe Forums - View Single Post - Spanair accident at Madrid
View Single Post
Old 21st Oct 2008, 18:29
  #2237 (permalink)  
justme69
 
Join Date: Aug 2008
Location: Canary Islands, Spain
Posts: 240
Likes: 0
Received 0 Likes on 0 Posts
Sorry it didn't come across more clear that those "percentages" were only a wild indication of my feelings, not an actual analysis of the situation. To quote myself:

Again, this is a "rough" PERSONAL opinion, nothing more.
So indeed, the percentages can be freely changed to just about anything you want as long as the order of importance and relative amount is similar. I.e. the copilot 40%, the pilot 30% and 30% for the rest of the factors.

It's just a way of expressing my view, not an actual study of the issues involved, and with the information we have in hand right now. And yes, I do not have hardly any knowledge at all about the aviation safety industry.

But I do believe that this particular case is one where relatively few factors were the real culprits. I believe that work conditions, operations, training, safety culture, etc, had little to do and it was more the case of a single, human mistake that coupled with an unfortunate, untimely technical fault.

I don't think that either, the mistake or the technical malfunction, as it has been on-going in MD-82's for a long time, could've been really avoided (in this particular case, more TOWS tests should've been required, but again, the TOWS could've failed just as well between the time they were tested and the time they were needed). And there is no way to AVOID (not reduce, AVOID) human mistakes. They will always keep happening.

Imagine the PERFECT scenario. The pilots are 100% well trained. The work conditions and operations are OPTIMAL. The airplane is in perfect shape. All tests were done and it all was fine.

The pilot forgets to set the flap. He just forgets. His mind tells him the flaps are set but they are not. It can happen, right? If you don't agree it can happen, then indeed there is no need for TOWS.

So, in spite of everything "perfect", the pilots manage to just miss the setting of Flaps the 2 or 3 times they are required by the SOP i.e.

And just 1 minute before take off, the TOWS in the MD-82 fails.

So now, where does the "blame" fall? Even more training? We established that it was optimal. Even better SOPs/checklists? We established they are the best they can be. Even more maintenance? We established the airplane was in perfect condition and recently tested. Better management? Why, we said conditions and operations were perfect.

It's ENOUGH of a condition for the pilots to miss this single item and, in the case of the MD-82, the alarm failing to operate for this accident to be, likely, unavoidable. Sure better training could perhaps allow them to recover the airplane on time and not enter the full stall condition, but we all know that it is hard to trust that an aircraft fully loaded with tail wind, close to the ground and speed way too slow to properly climb after ground effect can be necessarily recovered after running out of runaway space.

There is only one of two conditions for this accident to not EVER (in practical terms) occur:

-The pilots can NEVER make a configuration mistake.
... or
-The TOWS can NEVER fail right before the takeoff.

But the pilots are humans, and therefore, the first one can not be put in practice. And the TOWS are an electrical machine and, therefore, the second one can't be implemented either.

When they both align, no other factor is NEEDED (it may exist, but it is not needed) for these accidents to happen. In some "perfect" circunstances (which are not quite the case in Madrid, BTW), this cheese would have ONLY two holes. If you want more holes, you need i.e. to make sure there is some way to detect "FOR SURE" that the TOWS didn't fail right before the takeoff. Then you'll have a third hole, which may also be missed by the pilots etc, of course, but at least it's there. Right now, there are only two in a perfect scenario.

But, of course, in Madrid's case, the scenario wasn't perfect. The TOWS had only (theoretically) been tested by the pilots some 5 hours before, not inmediately before take off. If tested, it would've likely be found defective and the airplane AOG.

Also, maintenance was called on a "smaller problem" that was actually related, but they failed to figure it out.

And the flight's conditions weren't "perfect" because of the delay for the "rat probe heater failure", so everybody was somewhat rushed and distracted (but not enough to justify making extra, basic, mistakes, but making them more likely nonetheless).

Etc, etc.

Last edited by justme69; 22nd Oct 2008 at 00:19.
justme69 is offline