The Wet Test

A blue-suit, civilian, and contractor test team at Edwards AFB, Calif., has been taking the RQ-4 Block 20 Global Hawk unmanned aerial vehicle through a series of taxis at various speeds on a wet runway to ensure this version of the UAV with its electrical braking system—with differential brake capability and anti-skid functions—can handle the job like the smaller Block 10 variant with a hydraulic brake system. Dave Tangren, lead flight systems engineer with the 452nd Flight Test Squadron, explained that with the Block 20’s “completely new landing gear and brake system, we’re looking closely at anti-skid and stopping performance.” The test takes only a minute, but preparing and sustaining the wet runway follows an orchestrated effort involving civil engineer, contracting, and firefighting personnel, who prepare the runway by sweeping, watering, and applying special foam to retard water runoff. The team says the test results are positive. (Edwards report by Kenji Thuloweit)