Boeing has said that they would quickly and openly comply with whatever air regulation authorities, anywhere in the world, decides that they should change as a result of this accident.
A newspaper went so far as to openly said that Boeing is already studying a TOWS re-design modification. (
Boeing evalúa un cambio en la alarma de los MD · ELPAÍS.com )
But Boeing, of course, needs to be careful right now. Because they have a civil law suit on going in the USA on behalf of some of the victim's families, they can not readily imply that a TOWS re-design is a good idea, as it may play against them in the eyes of a judge/jury.
TOWS, like any electrical systems, can fail at any time w/o much warning. Boeing is going to argue that putting an alarm to alert of a malfunction on an alarm is ... well, you get the point.
The main reason of the accident seems to have been an user error that prevented setting a mandatory item (flaps/slats). Therefore, other systems (i.e. a mandatory TOWS test) could just as well have been ignored by the pilots.
The airplane can fly just fine without the TOWS, of course, so there is no "absolute need" to make the system overly redundant or deploy yet another alarm when the TOWS alarms fails.
The TOWS is there for ADDED safety, not for primary safety reasons. The LAPA accident had the TOWS working and yet, the pilots still tried to take off w/o flaps.
So, in the event of user errors, I think that the plane can both: fly without TOWS (of course, as long as slats are out i.e.) or fall down with the TOWS working for, basically, the same issue (i.e. not making sure flaps are deployed, as in LAPA case).
When Boeing found out about this 20 years ago (Detroit accident), I guess they evaluated and concluded that the best, although not perfect solution, at the time, was to run a TOWS test right before each flight. Also the cheapest, mind you.
They decided against setting a lighted indicator of operationability in the instrument panel of the cockpit. I don't know why, but I guess that such a system was deemed unlikely to be consistenly checked by the pilots, plus it would give the false sense of security that the TOWS was working, while the truth is that it would've only signaled if the TOWS was receiving power (i.e. the TOWS could still fail from an electronic logic board malfunction, a blown loudspeaker, etc). The TOWS must positively be tested and the alarm HEARD by the pilots, or else, there is no guarantee that they are working even if some "light indicator" signals they are receiving power.
Checking the TOWS shortly before take off doesn't prevent the TOWS from failing between the time they were tested and the time they are actually needed, but reduces the chances significantly. And it would render a "lighted failure indicator" redundant and almost useless. The pilots are not going to consistenly stare at a lighted indicator to see if it's on as they push the handles for takeoff and hear "silence".
And as any pilot can atest (specially Airbus ones) ... electrical systems such as TOWS, and even more important ones, can fail absolutely at any time without much prior warning.
This time around, though, I have the feeling that Boeing could and should easily retrofit the TOWS with additional logic that would give a positive indication of the system being operative instead of silence when the take-off conditions are ok.
But if the CIAIAC suggests that they should change the TOWS design, besides not having authority to make it a regulation, Boeing is gonna be upset because lawyers are going to use it as proof that the TOWS, a +30 years old design that was deemed safe at the time by regulators, is actually "bad".
If Boeing voluntarily changes the design now, same thing: everybody is going to finger point them as guilty.
All this, assuming that the TOWS indeed "broke" (i.e. R2-5 failure) and not that it was working fine but was disconnected by mistake (i.e. LEFT GRND RLY c/b popped), like in the MAP case in Lanzarote.
But after all, it doesn't seem to be too bad of a design if, due to its potential malfunction, it only failed to prevent the Spanair accident in 30+ years (the Lanzarote incident was a case of the TOWS disconnected on purpose by pulling a c/b and the crew not checking for activation/operation and the Detroit one was for unknown reasons, so perhaps it was also deactivated on purpose on that case, we could assume, and the crew didn't test them either).
And yet, even the Spanair case, the crew also failed to check the TOWS (SOP didn't require it) while Boeing warned to make checks before each flight as the only valid means to verify its operation.
If a TOWS check wasn't even required on the Spanair SOP, what makes anybody think that a "check lighted indicator for TOWS active" item is gonna show up in the checklist, much less consistently followed?
I guess Boeing is gonna have to wait until people forget about this accident and then silently start offering an upgraded replacement TOWS kit to their clients, one that signals that it's working during take off with some sort of noise instead of with silence, hopefully.
Out of curiosity: is there any airplane that has a TOWS that, when the handles are set to takeoff while on the ground, auraly signals the "OK to takeoff" condition or do all remain silent unless there is a bad configuration problem (or they are broken
)?