A Marine Corps AH-1W Cobra engages targets during a close-air support exercise over the Chocolate Mountain Aerial Gunnery Range, Calif., April 3, 2012. A fatal accident at the range involving a Cobra and a UH-1Y Huey has been blamed on malfunctioning rotor lights. (Cpl. Patrick P. Evenson / Marine Corps)
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The lack of lights marking the tips of rotor blades — a problem first identified in 2005 — led to the fiery fatal collision of an AH-1W Super Cobra attack helicopter and a UH-1Y Huey utility helicopter last year over a Southern California gunnery range, an investigation found.
All seven Marines aboard both aircraft died in the midair crash, which happened on the evening of Feb. 22, 2012, shortly after the helicopters had stopped to refuel and arm weapons for the training flight in the Chocolate Mountain Aerial Gunnery Range north of Niland, Calif.
The Marines were assigned to Marine Light Attack Helicopter Squadron 469, based at Marine Corps Air Station Camp Pendleton. Lt. Col. Thomas A. Budrejko, 37, and Capt. Nathan W. Anderson, 32, were piloting the two-seat AH-1W. The Huey crew included the pilots, Capts. Benjamin N. Cerniglia, 31, and Michael M. Quin, 28, and crew chiefs Sgt. Justin A. Everett, 33, and Lance Cpls. Nickoulas H. Elliott, 21, and Corey A. Little, 25.
The Huey had no working rotor-tip lights at the time of the collision, the lead investigator found, and the additional lack of infrared position lights on the Huey made it even harder for the Super Cobra pilots to see the Huey and maintain a safe distance as they followed it after the refueling stop. Even worse, the rotor-tip lights on the Marine Corps' growing fleet of upgraded H-1 aircraft — the UH-1Y and the AH-1Z — routinely fail with use, often due to broken parts or misaligned connections that provide electrical power.
“The rotor blade tip lighting system … is deficient,” the investigator wrote in the report, approved by Maj. Gen. Andrew W. O'Donnell Jr., the 3rd Marine Aircraft Wing commander at Marine Corps Air Station Miramar in San Diego. Marine Corps Times received a copy of the report, which was completed and sent to the wing on June 13, through a Freedom of Information Act request.
The system's “unreliability … has been well documented in the test community,” the investigator wrote, noting an October 2005 “Yellow Sheet Report” that discussed the problem, which was identified during testing of the newer H-1 aircraft that are replacing the Marine Corps' UH-1Ns and AH-1Ws.
The section of two aircraft was en route to the live-fire range for exercise “Scorpion Fire” and landed at the forward arming and refueling point about 7:30 p.m. The Super Cobra carried no ordnance. The Huey, an upgraded “Yankee” version with four rotor blades and improved navigation, communications and electrical systems, carried six 2.75-inch rockets and 800 rounds for its .50-caliber machine gun.
Thirteen minutes later, the Huey, serving as the flight lead, took off from the FARP and headed into Range 2507 North. The Super Cobra followed.
The lead investigator found the lack of rotor-tip lights on the Huey “directly contributed to the mishap,” but he did not fault the aircrews for the collision. Instead, the investigator cast wider blame on the H-1 community, including gaps in procedures and maintenance manuals and complacency from crews flying the helicopters without working tip lights.
“There is a tremendous lack of reporting of inoperative blade tip lighting systems in the H-1 community and no incentive to do so, despite the overwhelming sentiment from the fleet that the blade tips rarely, if ever, work,” he wrote.
The investigator, as well as pilots he queried, said rotor-tip lights worked on new helicopters received from Bell Helicopter Textron Inc., in Amarillo, Texas, which is building and upgrading the helicopters. But they didn't stay working for long.
“The lights are operational when the aircraft are first delivered,” the investigator wrote, “ … but within approximately 20-30 hours, the blade tip lights stop working.”
Many pilots and maintainers didn't bother to repair or report inoperable lights.
“It is as if the community has acquiesced to the lights never working,” he wrote, warning that “the longer the problem exists, the less it is reported, the less higher headquarters formally knows about the issue and the less likely funding for a replacement system will be authorized and the replacement system implemented.”
One solution, identified by the H-1 program office at Naval Air Systems Command, is to swap the helicopters' existing AC-powered system to a DC-powered system, providing more reliable power, the investigator wrote. But that “would require refitting (or completely building anew) every blade in the upgraded H-1 community.
“A new, reliable blade tip lighting system should be funded and implemented … as soon as possible,” he added.
Helicopters have a combination of position lights, some seen by the naked eye, and some infrared seen by night-vision systems, as well as rotor-tip lights that delineate the spinning blades, all meant to enable pilots to keep safe distances and avoid collisions.
“IR position lights are the best source of situational awareness between aircraft flying in formation on NVGs,” the investigator wrote in the mishap report, “and the upgraded H-1s should have them.”