Lighter-Than-Air > Tethered Surveillance Aerostats Helium filled aerostats are typically utilized as a platform to carry surveillance radars to altitudes reaching 15,000 feet while tethered to the ground by a single tether. ILC has manufactured aerostats with helium volumes ranging from 56,000 to 595,000 cubic feet. The length of these aerostats ranges from 107 feet to 240 feet. ILC conducted the detailed design of the initial Class IV aerostat configuration for the USAF. The Class IV design incorporated changes to the original Family IID design related to the shape of the hull and fins, as well as relocation of attachment patches to improve aerodynamic stability of the aerostat and facilitate mooring. The Class IV design is utilized in all current 275,000 and 420,000 cubic foot aerostats. The 420,000 cubic foot aerostat utilizes a Tedlar™/Mylar™/Polyester fabric envelope material developed and qualified by ILC Dover. The Class IV aerostat design has survived hurricane force winds in excess of 90 mph and has operated in winds in exceeding 65 mph. ILC has manufactured all the operational Class IV aerostats. ILC has a strategic alliance with TCOM, L.P. for the manufacture of large tethered aerostats. The alliance combines TCOM's unique capabilities related to LTA systems integration, dynamic modeling and analytical tools with ILC's extensive materials developement capability. ILC assists TCOM with the manufacture of their 71M® aerostat envelopes for TCOM's U.S. and international customers.

56K Aerostats Used for Sea-Based Border Patrol, Drug Interdiction Volume: 56,000 cf. Major Diameter: 36.5 ft Length: 109.5 ft Payload/Altitude: 800 lb. to 3000 ft Fabricated to date: 19 ea. w/two on contract 275K Aerostats Used for Border Patrol, Drug Interdiction, TV Marti (Television to Cuba) Volume: 275,000 cf. Major Diameter: 62.5 ft Length: 187.0 ft Payload/Altitude: 1000 lb. to 12,000 ft Fabricated to date: 14 ea. 420K Aerostats Used for Border Patrol, Drug Interdiction Volume: 420,000 cf., Major Diameter: 69.5 ft Length: 208.5 ft Payload/Altitude: 2000 lb. to 15,000 ft Fabricated to date: 14 ea.

56K Aerostat 275K Aerostat 420K Aerostat TCOM 71M® Aerostat