High-Intensity Radiated Fields
HIRFSection 10: Environmental Qualification (DO-160)
Definition
The high-level radio frequency electromagnetic environment produced by ground-based and shipboard radar, broadcast transmitters, satellite communication stations, and other high-power RF sources that can illuminate aircraft during flight or ground operations. The HIRF environment can induce currents in aircraft wiring sufficient to cause upset or damage to avionics equipment. Regulatory requirements for HIRF protection are defined in 14 CFR 25.1317 (FAA) and CS-25.1317 (EASA).
Where This Shows Up
HIRF protection is addressed at both the aircraft level and the equipment level. Aircraft-level HIRF testing or analysis determines the electromagnetic field levels that penetrate to equipment installation locations (the internal HIRF environment). Equipment-level HIRF protection is verified through DO-160 Section 20 radiated susceptibility testing at levels derived from the aircraft-level HIRF assessment. For critical and essential systems, a HIRF compliance plan must demonstrate that the combination of aircraft-level shielding and equipment-level immunity provides adequate protection against the external HIRF environment defined in the regulations. The HIRF environment is defined as field strengths from 10 kHz to 18 GHz.
Primary Sources
Regulatory requirement for HIRF protection of aircraft electrical and electronic systems.
Section 20 (Radio Frequency Susceptibility) — equipment-level test method used to verify HIRF immunity.
Aircraft HIRF Environment and Related Test Procedures — defines the standard HIRF environment and aircraft-level test methods.
Across Jurisdictions
14 CFR 25.1317
HIRF protection requirements are codified in 14 CFR 25.1317 with compliance guidance in AC 20-158A and AC 25.1317-1A.
CS-25.1317
HIRF requirements are in CS-25.1317 with acceptable means of compliance in AMC 20-158.
Related Terms
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