Romancing the Stone

Youre perfectly describing ROMAMCING THE STONE. Starts with girl reading by fireplace. Flying to Colombia, Joan is diverted from the rendezvous point by Colonel Zolo—the same man who ransacked her apartment looking for the map—by tricking her into boarding the wrong bus. Instead of heading to Cartagena, this bus goes deep into the country's interior. Ralph realizes this and begins following Joan. After Joan accidentally distracts the bus driver by asking where they are going, the bus crashes into a Land Rover, wrecking both vehicles. As the rest of the passengers walk away, Joan is menaced by Zolo but is saved by the Land Rover's owner, an American exotic bird smuggler named Jack T. Colton. Joan promises to pay Jack $375 in traveler's cheques for getting her out of the jungle and to a telephone. (This is the plane scene.

Jack and Joan travel the jungle while eluding Zolo and his military police. Reaching a small village, they encounter a drug lord named Juan who is a big fan of Joan's novels and happily helps them escape from Zolo.

That is where your recollection ends. You say you watched half the film until commercial break and are 'pretty sure' it's not Romancing the Stone but have you checked because the chances of another film existing with these scenes, it this order, in that time period with a Kathleen Turner lookalike are astromomical