I'm pretty sure this has been mentioned here before, but it's new to me, so I thought I'd mention it again.

In Uncanny X-Men #429, Professor X tells Juggernaut to get Northstar to fly him to Vancouver, because he's a qualified pilot (!). (Possibly also because he's Canadian, though that's not brought up.)
Juggernaut shows up in Vancouver by the end, so Northstar is present in the issue, though he isn't seen at all.

~ Le Messor
"It's tough to climb the ladder of success, especially if you're trying to keep your nose to the grindstone, your shoulder to the wheel, your eye on the ball, and your ear to the ground."