SBIR-STTR Award

Select Engineering Services (SES) is a leader in developing, testing, and implementing frangible structures for airfield use worldwide. We have developed a large range of composite structures to improve the performance and quality of Air Force assets while decreasing costs to maintain these structures. Military and commercial aviation rely heavily on Navigation Aids (NAVAIDS) for positional awareness, landing aids, and meteorological information. NAVAID instrumentation is almost exclusively attached to towers located within the frangible zone of an airfield. NAVAIDS such as Instrument Landing System (ILS) / Glide-Slope (GS) towers are located in close proximity to a runway and are required to be frangible (ability to break away) when struck by a wayward aircraft. SES has recently demonstrated (through full-scale impact testing) that frangibility can be designed into large airfield structures such as ILS/GS towers. SES is uniquely positioned to extend frangibility concepts to cabling, ladders, and accessories associated with such structures. SES will conduct a rigorous requirements analysis, market survey, and feasibility analysis of commercially available cabling, ladder, and accessories to be used to develop a complete frangible ILS/GS solution. Results of Phase I are expected to integrate naturally with ongoing development and qualification of a complete frangible ILS/GS solution.

Benefit:
Every major airport has mission specific equipment located within the frangible zone. Frangibility requirements extend to both military and commercial environments. Frangibility requirements for Instrument Landing Systems (ILS) / Glide-Slope (GS) towers are often waived due to non-existent solutions. Results of Phase I will naturally integrate with ongoing development and qualification of a complete frangible ILS/GS solution. SES has recently conducted full-scale frangibility testing of an ILS/GS towers indicating that frangibility can be designed into these large airfield structures. Currently there are no known frangible solutions for necessary cables, ladders, or accessories that are attached to these structures. Following qualification of frangible cables, ladders, and accessories, these necessary components can then be integrated with other qualified frangible structures to provide a complete frangible solution to both military and commercial environments.

Keywords:
Frangible Tower, Safety, Composite, Navigation Aid, Instrument Landing System, Frangible Climbing Ladder,

Select Engineering Services (SES) has developed a composite Instrument Landing System (ILS) tower that improves sustainability (by eliminating costly maintenance) and increases airfield safety through a frangible design. Current ILS towers are made from steel components and require costly Mobile Depot Maintenance (MDM) to mitigate corrosion. The development of frangible structures has primarily focused on qualifying the frangibility of the structure itself, without regard to accompanying accessories and attachments that are also part of the system. The focus of this Phase II effort will be to design, develop, qualify and build electrical cables, a ladder system, and a lightning protection system that does not impact the frangible properties of the tower. SES’s approach will be to develop and qualify the necessary accessories and components in order to conduct Formal Qualification Testing (FQT) on a full-scale tower with integrated accessories (e.g. cabling, lighting protection). SES will produce and deliver working prototypes of a pull-apart frangible power cable, pull-apart lightning protection down conductor, and an extendable ladder climbing solution ready for installation at any given site. This technology will provide a complete frangible ILS Tower solution that increases safety while decreasing maintenance costs.

Benefit:
Development of frangible cables, ladders and lightning protection systems (associated with airfield support structures) will increase airfield safety during airfield operations. In the event of an impact from a wayward aircraft, the frangible towers will give way and allow the safe operation of the aircraft. SES will develop several different products (frangible cables, ladders and lightning protection system) during this SBIR project, all of which will be specifically designed for use on frangible composite ILS Towers. The developed accessories and ladder system could potentially be applied to other frangible items such as approach lights, TACAN towers, street lighting poles, etc.:

Keywords:
Frangible, Composite, Towers, Lightning Protection, Ladder, Maintenance