assuming no head winds blah blah blah about half an hour ( and certainly 20 mins fits that) still too long and they ignored repeated attempts at contact
Up thread I mentioned that the controller did not get acknowledgment of an instruction to change to a new radio frequency at hand off. It was his duty to continue to make the instruction until he did get an acknowledgment.
Subsequent attempts to contact the aircraft were inhibited due to the aircraft being on the wrong frequency.
To you and I it occurs that the aircraft pilots should have expected that frequency change. I don’t know why that change was not made or pursued. I don’t know why the controller didn’t continue until he got an acknowledgment. I believe the record shows he made one attempt, and didn’t follow up.
When listening to these radio interviews it’s sometimes easy to get things somewhat mixed up, or morph what was said to the point of inaccuracy, but I believe this is an accurate depiction of how this issue was addressed.