The most obvious use case for classic UFO was to "patrol" an area of high alien activity for signs of an alien base or to shoot down a few scouts to bump up the happiness rating there.
For me, the logic would be to send an interceptor out to escort a dropship back to base.
I had a dropship shot down once, because a UFO fighter appeared as if by magic, right in front of it as it was returning to base and the interceptor didn't reach the UFO in time to save it.
Given there's only space for one weapon on that craft it doesn't make much sense to me that you can't deploy an escort ship to fly out to a dropship as soon as it's in range, and then escort it home. Or, escort it to and from the mission site if it's near enough.