May 15, 2026
Originally published October 24, 2022
Aircraft icing is a serious aviation safety concern. Ice buildup can increase weight, restrict moving parts, degrade sensor performance, and reduce visibility. At cruising altitudes, often below -60°F, moisture in the atmosphere can quickly freeze on aircraft surfaces and avionics components.
To ensure safety and performance, avionics and aerospace equipment must undergo rigorous icing test procedures as part of RTCA DO-160 environmental qualification standards. These DO-160 icing tests verify that avionics and electrical equipment can operate safely in extreme icing conditions.
DO-160 Icing Test Categories
A DO-160 aircraft icing test is an environmental simulation used to evaluate how airborne equipment performs when exposed to freezing conditions, ice accumulation, and moisture.
The Radio Technical Commission for Aeronautics (RTCA) standard defines environmental test requirements for airborne equipment, including icing conditions. Section 24 of DO-160 defines three equipment categories that are susceptible to aircraft icing.
Category A: External Equipment Exposure
Equipment installed externally or in an area of the aircraft that is not temperature controlled. The concern is ice or frost forming from condensation when exposed to extremely low temperatures.
Category B: Moving Parts
Equipment with moving parts that are inhibited in operation from ice buildup.
Category C: Water Accumulation Risk
Equipment or surfaces where water accumulation is a risk and is not temperature controlled. The allowable thickness of ice buildup is determined by the equipment’s performance standards.
Icing Condition Test Procedures
Tests for the three equipment categories have application-specific temperature and moisture cycles. All require thermal chambers to provide the temperature extremes called for in the standard.
Category A Test Procedure
Category A is intended for equipment exposed on the outside of the aircraft. The device under test (DUT) is fitted with thermocouples, placed in the test chamber, and stabilized at the Ground Survival Low Temperature specified in DO-160. The DUT is then quickly transitioned to a warm (30°C) and humid (95%) environment until the DUT temperature reaches 5°C. This is repeated for a total of 3 cycles, after which the DUT is checked for proper performance at -10°C.
Category B Test Procedure
Category B applies to equipment to moving parts, requiring temperature and atmospheric pressure to be varied. The chamber’s relative humidity cycles between 95% and ambient room humidity as the temperature and pressure are cycled 25 times. After the final cycle, the DUT is stabilized at -20˚ C and checked that it meets its performance standards.
Category C Test Procedure
Category C tests equipment that is not operating, stabilized at a temperature allowing clear, hard ice to form with a fine water spray. When the ice is at a thickness required by its performance standard, the DUT is maintained at -20˚ C and checked that it meets its performance standards.
Test Preparation and Procedure
One of Elite’s thermal chambers used in icing tests
Prior to the actual test, preliminary information from the customer’s test plan is reviewed to confirm the DUT’s configuration. The test plan is developed by Elite after careful discussion with the customer on details such as the DUT’s operation, the ice thickness required, and the type of baseline test required to confirm success.
When the icing test is scheduled, the test chamber and its accompanying chilled water tank are prepared. The DUT is placed in the chamber in the configuration specified in the test plan. The DUT is given an operational checkout to establish a baseline, the temperature in the chamber is verified, and the icing process begins.
Setup inside thermal chambers for an icing test
Ice accumulation is checked periodically. When ice accumulation reaches the appropriate level, the water spray is turned off and the DUT is placed into the operating state and stabilized at -20°C.
The DUT is later brought to ambient temperature and checked for proper operation as given in the test plan.
DO-160 Aircraft Icing Testing with Elite
Elite provides RTCA DO-160 environmental and EMC testing in one fully integrated facility—helping you streamline compliance and reduce time to certification.
From aircraft icing tests to full environmental stress screening, our experts ensure your avionics perform in the most demanding conditions.
Contact our testing specialists to learn more about DO-160 icing test capabilities and our full range of aerospace qualification services.
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