Janicki Industries (Sedro-Woolley, Wash.) announced on June 17 that its expertise in building composite prototypes was tapped by Lockheed Martin in producing the Full Scale Pole Model for its F-35 Lightning II stealth fighter jet program. The model is now being used to test radar signature and other key performance data. High fidelity Radar Cross Section (RCS) testing of the Highly Accurate Low Observable (HALO) pole model has validated the accuracy of the predicted F-35 stealth signature performance over a broad elevation and frequency range.
Janicki Industries worked as a key partner with Lockheed Martin throughout the development and fabrication of the HALO pole model, beginning in 2006. The timeline for F-35 development drove several innovations during the project, including building a structural inner body in advance of final surface engineering. By building the center body concurrently with the aircraft engineering phase, the Janicki/Lockheed Martin team was able to start building the model more than a year in advance of receiving the final surface geometry.
Once the external shape of the model was established, Janicki Industries applied a surface to the center body, using a proprietary technology developed by its tooling engineers. This began by applying sprayable, expanding urethane foam to act as a foundation. The foam was machined, then covered with a material developed by Janicki specifically for the project. To address the entire surface of the model’s body in just two set-ups, Janicki’s largest machining center was used. The company’s custom 5-axis CNC machining centers are among the largest in the world, with envelopes of up to 100 ft by 20 ft by 8 ft (30.5m by 6.1m by 2.4m).
After completing the model’s body, the Janicki team began developing and producing composite external panels for the pole model. These panels were fastened to the finished body to replicate the F-35 aircraft for testing purposes. These panels required the strictest adherence to every design aspect so that the model would match the aircraft’s real production specifications. Janicki Industries produced highly accurate molds to fabricate the composite panels. After panel fabrication, Janicki converted the molds to specialized trim and drill fixtures, which resulted in significant cost savings for the F-35 project
During testing, the HALO model is rigged in a variety of orientations on the top of a test pole. The model is uniquely configured for either upright or inverted orientation on the pole. This requires it to be reconfigurable both structurally and cosmetically to accurately represent the airframe in either orientation.
Rather than address all pole-model assembly tasks at Lockheed Martin’s facilities as originally planned, the company tapped Janicki Industries’ extensive fabrication capabilities, entrusting the assembly of major portions of the final model to the Janicki team. The latter completed multiple technically complex assemblies, including wings, engine mounts, internal structure and inlet duct assembly.