Definition
A cockpit seating arrangement in which the pilot seats are positioned one behind the other along the longitudinal axis of the airplane, rather than side by side.
Plain English
The seats are lined up front-to-back instead of next to each other, so one pilot sits in front and the other sits directly behind.
Context Anchor
Seen when describing aircraft layout and the pilot’s sight picture during maneuvers such as eights on pylons.
Derivation
From the Latin tandem, meaning 'at length' or 'lengthwise.' The word entered English to describe a carriage with horses harnessed one behind the other, then was extended to bicycles, and finally to seating arrangements where occupants sit in line rather than alongside each other.
Why Pilots Care
Affects what each occupant can see, how the instructor provides guidance, and the placement of dual controls during training flights.
Analogy
Like the two riders on a tandem bicycle, one sits directly ahead of the other.
Intuition Check
Tandem seating does not mean two pilots are required. It describes where the seats are placed: one behind the other, not next to each other.
Example Sentence 1
Because the Super Decathlon has tandem seating, the student flies from the front seat and the instructor sits directly behind.
Example Sentence 2
Many tailwheel trainers use tandem seating so the student in front has an unobstructed view over the nose.