Definition
The internal air pressure of an aircraft tire, measured in pounds per square inch (psi), set to the value specified by the aircraft manufacturer. Correct inflation pressure is critical to tire performance, load capacity, and resistance to dynamic hydroplaning on wet runways.
Plain English
How much air is inside the tire. The aircraft's manuals tell you the exact number to use, and keeping the tire at that number matters for safe takeoffs and landings.
Context Anchor
You’ll see this term in landing gear, preflight inspection, tire servicing, and wet-runway hydroplaning discussions.
Derivation
Inflation comes from a Latin word meaning “to blow into.” Pressure comes from a word meaning “to press.” Together, tire inflation pressure means the air blown into the tire pressing outward strongly enough to support the airplane.
Why Pilots Care
Correct tire inflation pressure raises the speed at which dynamic hydroplaning can start, helping maintain tire contact with a wet runway and preserving directional control during takeoff or landing.
Grounding Statement
On a wet runway, the pressure in the tire helps determine how well the tire can keep contact with the surface instead of being lifted by water.
Intuition Check
Do not think of tire inflation pressure as just a maintenance detail. In this FAA context, it directly affects tire contact with the runway and the risk of hydroplaning on water.
Example Sentence 1
During preflight, the pilot checked tire inflation pressure with a gauge and found the nose tire was 8 psi below the value listed in the POH.
Example Sentence 2
Low tire inflation pressure on a wet runway allows dynamic hydroplaning to occur at a lower groundspeed than normal.