Dan1113 wrote:
This wasn't really what I would call a mistake, they knew it should be on and they deliberately had it off. Of course they figured nothing would happen but it did. They didn't have it off by accident.
You do realise how serious an allegation this is, don't you? So, do you have a source for it?

And, more to the point, do you have any reason to believe that the Brazilian report is wrong about this? Indeed, have you even read the Brazilian report?

The following possible hypotheses were listed in the attempt to explain this fact:
· Intentional switch-off of the Transponder by the crew;
· Transponder failure (continuous or intermittent)
· Inadvertent switch-off, through the handling of the Laptop;
· Inadvertent switch-off, through the use of the footrest; and
· Inadvertent switch-off, during familiarization/operation of the RMU.

Intentional switch-off of the Transponder by the crew
Discarded: The CVR did not show any indication that the N600XL crew had that intention. In the interviews, both pilots were definite regarding this aspect. Besides, the N600XL crew would not benefit from setting the transponder to STANDBY, as, for example, to fly at different RVSM flight levels, without clearance for that.
The reference, should you choose to have a look, is pages 241-242, and the report then goes on to discuss the other possibilities.

Long-haul flying - how to sleep your way around the world.