@PBL
Of course never without units - corrected.
@lomapaseo
I should have stated that my figure is true for construction / material related failures only. This does not include human error.
@Sdruvss
Interesting perspective.
I thought once more about the transcript. At 18:43:04 the crew briefed themselves that they have only the left reverser. OK, that's just stating that #2 is inop. But right after touchdown, at 18:48:26 the PNF (HOT-2) says "reverse number one only." To me, these words sound a bit odd, as "reverse" is a verb in its imperative, not the noun (the thing at the engine). So in other words I read that as a reminder to the PF to pull back only lever #1, which could imply "don't touch #2". Even when this was not the exact intention of that sentence, it could be misunderstood like that and could have influenced PF who has left lever #2 at CLB (if the DFDR has it right). Why?
Then I took another look at the MMEL published by TAM:
The big, fat, bold sentence says to "
not select thrust reverser on the affected engine". Yes, there is an "if": Only if a certain warning was triggered
in flight. This caution is not true if the affected reverser was disabled prior departure. In that case the applicable procedure says REV 1 AND 2 ... MAX as we all know now, but it is written in normal letters.
To me this appears like a negative contribution to human factors: Could the bold caution been stuck in their minds, because it is the biggest eyecatcher on that page of the MMEL?
Looks like human factors are not limited to man-machine interfaces but instead start with the manual. Could it be misleading in a stressful situation?