Portable Aircraft Hangar
Tectoniks Ltd., Shrewsbury, Shropshire, United Kingdom
The project involved the design and construction of a 23.3m (76 ft) span by 28.8m (95 ft) inflatable aircraft hangar that is fully portable and can be erected in a short time with a small crew.
The client required a rapid deployment, highly portable aircraft hangar that could accommodate aircraft with wingspans of up to 20m (66 ft). It would be used for the maintenance of aircraft in the field where no facilities were available for conducting maintenance under cover.
Other requirements included that the hangar be very compact when packed, contain no rigid parts and be easily transportable by air. It must be capable of installation on a variety of surfaces in extreme environments. It must be deployable by a crew of four people in two hours using no lifting equipment other than a forklift truck. Both ends of the hangar must be capable of opening quickly to provide unobstructed access across the span. The ends must be capable of opening using no more than two people and must take less than two minutes to fully open. Power requirements for the pressurization of the hangar must be as low as possible to permit the use of small portable generators.
To provide ends that could be fully opened to allow unobstructed access, clamshell-style terminations were used because they operate similarly to the folding hoods on boats, convertibles and baby strollers. They replace the rigid elements required to support the fabric with high-pressure inflatable tubes to produce a foldable hood that contains no rigid parts.
The hangar met or exceeded all of the requirements. Its structure contained no rigid parts, when packed it occupied a space of nine cubic meters (318 cubic feet) and weighed 1,270 kg (2,795 lbs). The solution for the opening of the ends was to use two small handheld capstan winches that pulled cords attached via pulleys to the clamshells. This enabled the ends to be fully opened by two people in less than two minutes. Since the inflatable portions of the hangar are of a welded construction they are virtually airtight. This permits the hangar to operate at pressures high enough to provide the structural rigidity required and greatly reduces the power requirements for the blowers that maintain air pressure. Once inflated, the blowers operate intermittently under the control of a fully automatic pressure control system. To produce a hangar capable of withstanding the range of environments required, the tensioned parts of the clamshell ends were shaped to provide as much stiffness as possible while minimizing drag. Fabrics were selected for their performance characteristics under extreme temperatures.