Is use of otrivin (.05%) nose drops in infants helpful in avoiding ear pain when flying?

Possibly: Otrivin (xylometazoline) is a decongestant that will shrink clogged nasal passages. if there is no cold or facial congestion, it will not have much effect. Swallowing helps open the passageways and clear the ears, so a good way to help your infant avoid ear pain is to make sure he's hungry by the time the airplane descends, and continuously feed from a bottle during descent.