The US Army hopes to deploy within the next three months an interim solution to a "brown-out" problem that has caused 32 helicopter crashes during the service's operations in Afghanistan and Iraq. The measure is intended to provide a temporary solution until the availability of aircraft featuring fly-by-wire flight controls, say senior commanders.
The army says it can start to reduce the risk posed by brown-out conditions by taking two steps to improve situational awareness in the cockpit, and in late March began using pre-certificated flight equipment that will show basic symbology indicating hover and drift on a new cockpit display. The solution involves linking a Honeywell embedded global positioning/ inertial navigation system with a 100 x 100mm (4 x 4in) Rockwell Collins multifunction display.
"In the short term this is not optimum, but don't forget those crews have nothing right now," says George Dimitrov, chief of rapid prototyping for the Army Applied Technology Directorate at Fort Eustis, Virginia.
A second cockpit upgrade aimed at countering brown-out conditions is scheduled to begin in June. Under this, the army's cargo helicopter programme office is seeking technologies that can see through the blinding dust clouds kicked up by a helicopter's rotor blades in desert environments.
BAE Systems is offering its Radar-Enhanced Vision System, which blends images from a 94GHz millimetre-wave radar and an infrared camera into a common synthetic picture.
Hover and drift symbology added during the first phase of the upgrade process can be overlaid on this image.
The army is not releasing funds for production and installation until the flight tests in each phase are complete, and the effort is limited to its Sikorsky UH-60A/L Black Hawk and Boeing CH-47D Chinook fleets.
Boeing's AH-64A/D Apache Longbow attack helicopter already has basic hover and drift symbology, and is first in line to receive a new fly-by-wire system based on technology borrowed from the army's terminated Boeing/Sikorsky RAH-66 Comanche project.
The US Marine Corps, which has also recently lost several helicopters to brown-out incidents, is using landing zone mats to reduce the amount of dust that its aircraft kick up. The service is also investigating other solutions, such as using chemical agents to address the dust problem.
STEPHEN TRIMBLE / NASHVILLE
Source: Flight International
