The purpose of this document is threefold: (1) to review the problem of moisture in avionics equipment, (2) to outline methods for correcting conditions of excess moisture in existing avionics installations, and (3) to recommend design practices for new avionics cooling system installations which will minimize the adverse effects of moisture. The problem of moisture in avionics has been brought into focus by the widespread use of air cycle refrigeration in forced-cooled black-boxes, and by the lack of recognition of the moisture sensitivity of most avionic circuitry. This document does not relieve the avionics designer of his obligation to meet any other humidity requirements which may be applicable to the avionics. Because the air conditioning system is inoperative when the aircraft is parked or stored, the aircraft and its equipment must withstand the effects of the outdoor environment (e.g., humidity, fog, rain, and surface condensation).
SAE ARP987A-1997 history
2020SAE ARP987B-2020 The Control of Excess Humidity in Avionics Cooling
2010SAE ARP987B-2010 The Control of Excess Humidity in Avionics Cooling
2003SAE ARP987A-2003 The Control of Excess Humidity in Avionics Cooling
1997SAE ARP987A-1997 The Control of Excess Humidity in Avionics Cooling
1970SAE ARP987-1970 Control of Excess Humidity in Avionics Cooling