ＣＦＩＴは乗務員が航空機を完全にコントロールし、すべてが正常に作動しているにもかかわらず、地面に激突する場合に起こるものである。 When the flight crew has their aircraft under control, everything is working normally and yet it still crashes into the ground, that's CFIT.
By that, Boeing means that there may also have been other problems, but that an accident could have been avoided if the crew had done their job correctly.
Japanese Dictionary
