The other piece of the puzzle

Look at my January 10 'another ICYMI" item.  

Now consider, 'chatter' at the beginning of the year indicated jihadis had a new technique for an attack using an aircraft.

'Dirty bomb' on an airliner anyone?  A twofer - blow it up shortly after take off or on approach over a major city and you both kill the passengers and spread the radioactive materials.

https://americafirstreport.com/dhs-quietly-issues-terrifying-alert-that-al-qaeda-is-planning-another-plane-attack-with-new-techniques-and-tactics/

As there apparently was radioactive material found in the German raid on jihadis there, the intelligence, as reported, seems at least partially confirmed by events.