In the late 70s our local aero club ran a series of courses for frequent passengers based on the US AOPA Pinch Hitter course. While the background was What If , the emphasis was on making flying more enjoyable for non pilot partners by giving them a better understanding of what was happening in flight and giving them enough skills to participate in the flight.
The course consisted of a one day series of briefings, including lunch to make it more sociable, and about three hours flying from the pax seat. If the family owned an aircraft the flying lessons were done in that aircraft.
Course covered Aircraft control, communication and navigation. Everything was reduced to an absolute simplest terms and ways of doing. e.g. navigation = Follow something e.g. Road, Rail River etc.
Most attendees were wives of pilots and most got to the approach and landing lesson, some even went on to learn to fly. One bloke, who flew a lot as a pax in a C337 and was worried that his pilot would have a hearty, was actually making survivable landings after 5 hours. Turned out that the pilot outlived the pax by more than 20 years.