Temperature and Altitude Testing
Section 10: Environmental Qualification (DO-160)
Definition
DO-160 Sections 4 (Temperature and Altitude) and 5 (Temperature Variation) define tests that subject equipment to the extremes of temperature and altitude expected during aircraft operation. Section 4 tests include short-term and steady-state exposure at temperature extremes combined with altitude, ground survival temperature exposure, and (for unpressurized installations) decompression. Section 5 tests assess the equipment's ability to withstand rapid temperature changes.
Where This Shows Up
Temperature and altitude testing is fundamental to environmental qualification because electronic components exhibit parameter variations across temperature, and reduced air pressure at altitude degrades convective cooling and increases the risk of dielectric breakdown (arcing). DO-160 Section 4 categories range from A1 (mild, pressurized compartment) to D3 (severe, external installation on high-altitude aircraft). The selection depends on the installation zone: pressurized cabin, unpressurized compartment, or external. Equipment is typically required to operate throughout the temperature range and survive (without permanent damage) at the temperature extremes.
Primary Sources
Section 4 (Temperature and Altitude) and Section 5 (Temperature Variation) — define the applicable categories, test conditions, and procedures.
Related Terms
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