PERFORMANCE

Density altitude

FLIGHT SCIENCE / CONCEPT REFERENCE

SCIENCEConditions & principles

Pressure altitude adjusted for the effect of nonstandard air temperature.

REFERENCE COVERAGE3 / 3 editorial sections

PROVENANCE1 linked source

LAST RETRIEVED2026-09-05

Editorial section coverage describes the article structure, not scientific validation or completeness.

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Source editions

PHAK · Chapter 11: Aircraft Performance ↗Edition / snapshot: FAA-H-8083-25C, 2023Retrieved: 2026-09-05

Retrieval dates record when Owl obtained the data; they are not publication dates or proof that a specification is current. Where the edition contains only a snapshot date, the original publication date is not recorded.

Mechanism

Warmer or lower-pressure air generally has lower density. Humidity also reduces density at the same pressure and temperature because water vapor is lighter than dry air.

Aircraft response

Lower density reduces aerodynamic force at a given true airspeed and can reduce available engine and propeller performance. Takeoff and climb performance can deteriorate.

Context & interpretation

Use aircraft-specific performance data for actual distances and limits. Density altitude is an atmospheric comparison, not the height indicated above terrain.

Physical relationship

ρ = p / (R T)

Ideal dry-air relation: density ρ, absolute pressure p, absolute temperature T, specific gas constant R.

Sources & context

PHAK · Chapter 11: Aircraft Performance

FAA · Retrieved 2026-09-05

Educational reference; original Owl summaries

Educational explanation of physical mechanisms. Aircraft-specific procedures, limitations and current weather information are separate references.