Additional application for sling-load missions

'BROWNOUTS' PROMPT ARMY TO WORK ON PRECISION-LANDING METHODS

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Date: April 21, 2003

Responding to dangerous flying and landing conditions common in the deserts of Iraq and Afghanistan, the Army is trying to develop a helicopter precision landing system to prevent loss of control during “brownout” conditions, according to Army officials and documents.

The Guided Launch and Recovery System (G-LARS), under development by the Aviation Applied Technology Directorate and Sierra Nevada Corp., gives helicopter pilots a more complete picture of their speed, relation to the ground and distance from desired positions than current technologies allow. The system, officials say, essentially serves as the pilot's eyes when snow or sand limits the field of view.

Brownout conditions occur when a helicopter's rotors stir up dust from the ground, reducing visibility and causing vertigo in some pilots. Similarly, snow can cause “whiteouts.” Brownouts have plagued desert air missions during both Operations Enduring Freedom and Iraqi Freedom. During one flight in Afghanistan in January 2002, for example, brownout conditions were blamed for the hard landing of a CH-47 Chinook, which injured several soldiers from the 101st Airborne Division and extensively damaged the aircraft.

From 1990 to 2002, the Army attributed a total of 66 Class A to C accidents -- the most serious accident classifications on the Army scale -- to brownouts. Also, “several” aviation accidents in Iraq in recent weeks likely were caused by brownout, according to an Army official involved with the G-LARS program. Many of those are still under investigation.

The problems caused by dusty conditions have prompted several Army aviation officials to speak out about a need to develop technologies to aid pilots during brownouts.

Most current anti-brownout technologies involve preparations of landing surfaces -- placing mats in an area or spraying it to prevent dust and sand from kicking up around the rotorcraft. However, those solutions are effective only for planned landings in friendly areas, and many -- including a spray dubbed “Rhino snot” by Marine forces at Camp Rhino in southern Afghanistan -- have received mixed reviews from units in the field.

“We haven't tackled how to fly in dusty conditions,” Lt. Gen. Richard Cody, deputy chief of staff for operations in the G-3 office, said earlier this month during the Army Aviation Association of America's annual conference in Ft. Worth, TX. “Every day, every takeoff, every landing [can be] a dangerous situation. The launching piece is dangerous, the recovery piece of formations is just as dangerous.”

In current and recent operations, Cody added, more aviators have been lost to accidents than to enemy fire.

The ultimate goal behind G-LARS, according to an Army information paper, is to allow pilots to safely perform takeoffs and landings and “safe and efficient high-hover operations” in both brownout and whiteout conditions. As an added benefit, the system could also aid in “sling-load” operations in which aircraft must hover low to the ground to pick up loads.

“It is very tough to hover an aircraft at 20, 30, 40 feet above the ground and not move,” Col. William Gavora, AATD commander, told Inside the Army April 16. “There is a certain degree of danger inherent in those operations. You tend to drift. To actually hover there . . . will make any professional pilot sweat.”

Currently undergoing testing on a UH-1 Huey helicopter at Ft. Eustis, VA, the G-LARS system consists of Global Positioning System technology, an Inertial Measurement Unit, a power supply and a display mounted to the side of the instrument panel. It is designed to tell the pilot how fast the aircraft is moving in any direction -- left, right, up, down, forward, backward -- away from a desired position on the ground. The system also informs the pilot how far the aircraft has drifted from the desired position and displays the aircraft's rates of climb and descent.

Future plans involve integrating the signal from the standard aircraft radar altimeter, which determines height off the ground, into the G-LARS display, Maj. Dave Wollons, AATD chief of flight test, told ITA last week. AATD also is considering integrating the G-LARS system onto the digital horizontal situation indicator currently being fielded to Army aircraft.

The system recently concluded successful initial flight tests in which brownouts were simulated by masking the cockpit to remove all outside references for the pilot, according to the information paper. During the tests, the pilot was able to use the G-LARS to perform normal takeoffs and landings at a designated spot; perform vertical takeoffs to a high-hover position; hold position over a designated spot to simulate sling-load operations; and perform vertical landing from a high hover to a designated spot.

“It performed very well,” Wollons noted, adding that AATD has tentative plans to fly and land the G-LARS-equipped Huey in actual brownout conditions in the next month.

The system has caught the attention of several Army aviation officials, including Maj. Gen. Joseph Bergantz, program executive officer for aviation, who flew in the modified Huey during the AAAA conference earlier this month.

“We need to take a hard look at this and see, in the near term, if this is a possible solution” to the brownout problem, Bergantz said at the convention after the test flight.

Gavora likewise endorsed further exploration of the system's capabilities, stating that G-LARS is “an interesting technology with potential application to the fleet.” -- Megan Scully