bird in flight

Difficult to begin with, but possible without guess with a lot of patience.
Great one, should be higher rated than only '2'.

Help, please?

Try to isolate the 3's either end, It's a tough one!!

For anyone who doesn't have as much time on their hands as I, here's a spoiler:

The 3 in column 18 starts in row 2. The 3 in column 2 starts in row 5.

That makes it almost logical except for a few easy guesses at the end.

Thanks for the hint.

Yes, thx for the hint.

Thank you.