No, it isn't. The question is whether you accept that the flight was hijacked and flown into the ground. Either (a) you accept that as a correct summary of events, in which case the answer is "Yes", or you doubt or question it, in which case the answer is "No", or you believe it to be incorrect, in which case the answer is again "No". If, for example, you believe that the aircraft was hijacked but may not have been flown into the ground, then the answer is "No", because you do not accept that the plane was both hijacked and flown into the ground.
It's interesting, by the way, that you've substituted the word "ditch" for the word "ground", thereby giving a false impression that the impact crater was a pre-existing feature.
Dave