3 mo. since surgery of torn meniscus. cleared back to work as flight attendant. during flight ok, on layover knee swells up. will this improve w/time?

Yes: At this early phase after surgery, the repeated pressure changes of going up and down in the plane can cause swelling in any surgical site. It sounds like standing and doing the work is ok, which is the good news. In time, your body will figure this out. For some, wearing a thigh high compression garment or a stretchy (neoprene) knee sleeve during flight helps.

Knee swelling: If you a concomitant problem in your knee, such as chondromalacia of the medial femoral condyle, this may be a persistent problem. You should check with your surgeon.