I used to fly a PA31 into YVR several times a day on a bag run. Once I was given a Taxi to position and hold clearance with a 747 on what looked like a pretty close in final. I must say he sure looked big

. I sat in position for about 30 sec before TO clearance but it felt like an eternity. I guess the controller heard the concern in my voice because his last words were " cleared for takeoff... and I bet you thought you were going to get squashed like a bug"