Definition
The maximum sustained rate at which an aircraft's speed decreases during the landing roll, achieved when braking, aerodynamic drag, and other retarding forces are applied at their highest effective level continuously rather than in brief bursts.
Plain English
The hardest steady slowdown the airplane can keep up during the landing rollout — not a quick jab on the brakes, but a strong, even slowing held all the way through.
Context Anchor
Seen in landing performance discussions when explaining how braking affects the distance needed to stop after touchdown.
Derivation
Continuous means kept up without pause. Peak means the highest level reached. Deceleration comes from Latin de- (down from) and celer (swift) — literally 'slowing down.' Together: the strongest slowing, held steadily.
Why Pilots Care
It directly determines the runway length required to stop safely under given conditions.
Analogy
It is like braking a car as firmly as possible without making the tires skid, and holding that firm braking all the way through the stop.
Grounding Statement
Picture the airplane just after touchdown: the wheels are rolling, the brakes are working hard, and the airplane is losing speed at the strongest steady rate it can safely hold.
Intuition Check
Peak does not mean a quick one-second spike here. In this phrase, it means the best slowing rate that can be maintained continuously during braking.
Example Sentence 1
The short-field landing chart assumes continuous peak deceleration from touchdown to a full stop.
Example Sentence 2
With reduced braking, the airplane could no longer achieve its normal continuous peak deceleration and required extra runway.