Mothballing
Dehumidification of FAF Aircraft
Long-term aircraft storage is a co mplex process, potentially requiring several thousand man-hours to return an aircraft to flight worthiness. A more ideal solution, particularly for the military, is to store aircraft ready for flight with fuel and delicate avionics systems in place. In ambient conditions, however, the flexible materials used in fuel tanks for certain aircraft, for example, cannot withstand prolonged storage. A dry air dehumidified environment makes that possible.

Dehumidification acts directly against moisture by removing water vapor from the air and is not affected by temperature and is thus able to be controlled without fluctuation. It is also significantly more energy efficient than other alternatives such as heat, which does not reduce the moisture content within the air itself.

After careful research and analysis, the French Air Force determined that to suit their long-term aircraft storage needs, a dehumidified hangar would provide the optimum solution. At Chateaudun (approximately 100km southwest of Paris) a number of hangars were constructed utilizing this dry air method, including a flexible enclosure of more than five million cubic feet within a larger concrete structure. Dry air dehumidification was supplied to this environment by a unit delivering 16,500scfm of dry air per hour.

The benefits of this project have been well documented, and include: increased aircraft availability, operational life and efficiency, as well as decreased maintenance requirements, construction and operating costs. The FAF has since used this solution as a model for similar needs, including construction and dehumidification of an 895,000 square foot enclosure to protect 25 Mirage aircraft.