How many 3 year olds use pacifiers???? That's for newborns.
Not sure, but if your 3 year old is a tantrum thrower, my suggestion is to buy one to carry on the plane with you whether you think your child needs it or not.
I was on a nearly full plane once and behind me was your classic wailing plane baby. We couldn't go 5 minutes of quiet before the baby started crying and kicking chairs backs, etc.
In the process of raising two, one of whom had real colic, I had built up a fairly high tolerance to this kind of stuff. When she barfed on the floor it never phased me. However, I was seated next to a young man who couldn't be over 25 and may have still been in his teens. Every time the baby even made even the slightest noise, he would cringe.
When the plane landed, I said to him "let this flight be the best dang birth control lession you're ever going to get."