Definition
An arrangement in which two seats, components, or items are positioned one directly behind the other along the aircraft's longitudinal axis, rather than side-by-side.
Plain English
One behind the other, in a line, instead of next to each other.
Context Anchor
Seen when selecting or describing the two ground reference points used for eights on pylons.
Derivation
From Latin 'tandem' meaning 'at length' or 'finally.' English speakers borrowed it as a joke for a carriage drawn by horses harnessed one behind the other (stretched out 'at length'). The aviation usage carries the same idea: things lined up front-to-back.
Why Pilots Care
Determines forward visibility for each occupant, ease of instruction, and how control inputs are demonstrated during training flights.
Analogy
Like riders on a bicycle built for two — one sits in front, the other directly behind, not side-by-side.
Intuition Check
Do not read tandem as “near each other” or “paired.” Tandem specifically means one behind the other on the same line, not side by side.
Example Sentence 1
The training aircraft had tandem seating, with the instructor sitting directly behind the student.
Example Sentence 2
With tandem seating the student in front has an unobstructed view of the pylons while the instructor monitors from directly behind.