This is a cool question. Kennings are a lot of fun to read and create. We don't see too many kennings in modern English. They are more specific to Old English and Old Norse poetry. A kenning is a metaphorical compound word or phrase that is used in place of a more concrete single word noun. For example, a boat could be called a "wave traveler" or a "sea steed." For an airplane, I like "air beast." You could easily modify the previous boat examples to work for an airplane. "Wind traveler" and "sky steed" both sound way more descriptive than "jet." "Sky streaker" isn't bad because of the contrails that they leave at high altitudes. So far, the kennings listed all make an airplane sound more glorious; however, you can use a kenning to make an airplane (specifically an airliner) sound quite boring—"sky bus."