looks like your airplane blocks may not be identical size. I always double check and square off my blocks before I sew the rows. Bought a large square ruler for that purpose.
It is a good idea to pin the rows as you put them together. That way you will see immediately if there is a problem. Sometimes, when the block is off just a little bit, it is possible to fudge the seam - but not when it's off by as much as you show.
It will be pretty when done though.