Before I start, I am so happy that you asked about this question! The Giver just so happens to be one of my favorites!
But anyways, let's begin!
So in The Giver, our main protagonist, Jonas, sees a plane flying over his community during chapter 1. It is a well-known rule in his community that aircrafts were not allowed to fly over the community. So naturally, he felt at confused and curious at first (it is stated that he hadn't seen an aircraft up close before). But then, the aircraft flies over their dwellings once again. At this point, him and others realize that it isn't a day-to-day cargo plane delivering supplies and are frightened.
So based off this, we can conclude that in The Giver chapter 1, Jonas feels frightened and confused after seeing the plane about a year ago from the current setting.