Seems to me the 9/11 terrorists did a pretty good job without a test run.
My husband is a pilot - you don’t need to fly to a place to gather timing, fueling etc. This sort of thing is available via aviation software.
Do you honestly think this was no more than an innocent, non-thinking joyride for grandma. I might be all wrong about my scenerio and the motive, but I’d bet anything there was secret dirty-work afoot with a motive that has to be kept secret from the people.