The crew of a Charlotte-based Air National Guard firefighting plane should have avoided the intense storm that fatally slammed the C-130 into the ground in South Dakota in July, investigators said Wednesday.
A six-week investigation found that the propeller-driven plane flew into a severe gust of wind called a microburst that blasted down from a thunderstorm. It crashed within seconds, killing four of its crew and seriously injuring two.
Accident investigators said the C-130s cockpit crew had noted turbulent air from thunderstorms about 10 miles west. They had also puzzled over an unexplained drop in airspeed, despite full power, during the planes first pass to drop retardant on the wildfire it was attacking near Edgemont, S.D.
The crew, part of the 145th Airlift Wing, discussed the airspeed problem but decided they could adjust to the conditions. The plane crashed on its second retardant-dropping pass over the fire about five minutes later, about the time a microburst lasts.
If you add all the pieces up, it was very clear they should not have attempted the second drop, said Brig. Gen. Randall Guthrie, the Air Force Reserve officer who led the investigation. With all apparent conditions, they should not have gone ahead.
The probe said two other factors substantially contributed to the accident.
The C-130s crew had puzzled over two conflicting alerts about thunderstorms, Guthrie said. One advised staying 25 nautical miles from storms, the other 5 miles. The crew believed the 5-mile distance to be correct.
In addition, a smaller plane flying a half-mile ahead of the C-130, guiding its retardant drop, first encountered a microburst that pushed it within 10 feet of the ground.
They struggled to keep that airplane flying, Guthrie said. A second small plane also reported more than moderate turbulence.
The crews of those planes failed to alert the trailing C-130 to go around the storm, the investigation found. Instead, the lead plane crew advised the C-130 to drop its load of retardant to lighten the craft to help it climb.
We felt like they had information and the importance of that information was not passed, Guthrie said. Those crews later said they also didnt really add all those factors up themselves.
The C-130 dropped the retardant but crashed seconds later, dropping into a lightly-wooded plateau, then into a ravine and breaking apart.
Killed on impact were Lt. Col. Paul Mikeal, 42, of Mooresville; Maj. Joseph McCormick, 36, of Belmont; Maj. Ryan David, 35, of Boone; and Senior Master Sgt. Robert Cannon, 50, of Charlotte. Two others were seriously injured in the crash: Chief Master Sgt. Andy Huneycutt and Sgt. Josh Marlowe of Boiling Springs.
Guthrie said a propeller broke off the plane as it crashed, creating an opening in the fuselage through which the two loadmasters stationed at the back of the plane walked to safety.
The guys in front landed the plane in a way that helped them survive, he said.
The full report on the crash has not yet been publicly released.
The North Carolina Air National Guard said Wednesday it will study the accident boards findings carefully to do all it can to ensure future tragedies do not happen.
NCANG continues to grieve with the families of its fallen airmen and continues to help them and all of its members deal with the loss, the guard said in a news release.
The families of the four crew members who died could not immediately be reached by phone Wednesday evening.
Charlottes Air Guard unit, with nearly 1,500 members, is one of four military units nationally that operates C-130 transports equipped for dumping slurry a mixture of water, fertilizer and red dye that coats the ground and repels flames for days to halt the advance of wildfires like those that vexed the arid West this past summer.
Typically, such drops are conducted in smoky conditions at low altitude, about 150 to 300 feet, which leaves pilots little room for maneuvering. Winds had been hampering fire control efforts that day, and authorities were concerned because a thunderstorm cell was approaching at the time of the crash, about 7 p.m. local time.
Called MAFFS, for modular airborne firefighting systems, the aircraft can be outfitted with a roll-on tank about the size of a delivery van that carries 3,000 gallons of liquid to remote fires.
Julys crash was the first in the 40-year history of fighting fires with C-130s equipped with MAFFS, and the first fatal accident in the history of the 145th Airlift Wing, whose origins date to 1946.
Staff writers Ely Portillo and Mark Washburn contributed.