RF Field Probe

F-35 Acceptance Test Facility

Lockheed Martin Aeronautical
Systems, Ft. Worth, Texas

 
 
Howland RF field probe inside the F-35 Acceptance Test Facility chamber
Photo by Ted King
Like the F-22, each production F-35 will undergo full RCS imaging measurements to verify that the aircraft's stealth characteristics meet specifications. Lockheed Martin Aeronautical Systems in Ft. Worth, where F-35 final assembly takes place, has built a dedicated facility for RCS acceptance testing. (This facility is similar, though somewhat larger, than the facility The Howland Company designed for Lockheed Martin to support F-22 production in Marietta, Georgia.) The special requirements of this unique testing scenario--a large quiet zone, handling full-scale aircraft in a production environment, and the need to accomplish testing quickly and with high confidence--have resulted in a unique, state-of-the-art production test facility. When F-35 production reaches peak rates, Lockheed Martin plans to cycle one aircraft per day through the Acceptance Test Facility.  

To assess the performance of the completed F-35 Acceptance Test Facility, Lockheed asked The Howland Company to perform field probe measurements. We designed a mobile, 50-foot tower probe system with motion control and RF subsystems which interface with the measurement system's instrumentation radar. We also delivered a custom data reduction and analysis software package developed by CompuQuest. We completed an extensive set of vertical and horizontal scans at both vertical and horizontal polarizations and 256 frequencies. Using the field probe data and CompuQuest's analysis software, Lockheed's engineers were able to determine that the measurement system is performing well within the parameters required for F-35 RCS imaging tests.

The Lockheed Martin issued a press release about the Acceptance Test Facility.

 
  RF field probe for the F-35 RCS Acceptance Test Facility   F-35A AA-1 outside the RCS Acceptance Test Facility  
Photo by Ted King   LM Aero Photo
A close up of the probe's tower base, drive system, and operator controls. The field probe can be easily moved to any position in the chamber for vertical or horizontal scans of the measurement aperture.   The Highly Accurate Low Observable (HALO) RCS pole model inside the RCS Acceptance Test Facility.