Although the co-pilot of a C-130J in Afghanistan was performing an unneeded and unauthorized high-power, rapid ascent takeoff when the aircraft crashed Oct. 2, that was not the cause of the accident crash, investigators said.
An The official investigation by the Air Force determined that a forgotten night vision goggle case had jammed the jamming a control yoke, directly leading to the was the cause of the crash that killed 14 people, and that neither the co-pilot flying the aircraft nor the takeoff maneuver itself were responsiblecontributed to the accident.
According to a transcript of the cockpit voice recorder released by the Air Force, the pilot of the Super Hercules, Capt. Jordan Pierson, was attempting to get his co-pilot, Capt. Jonathan Golden, more experience performing a high-powered takeoff.
An "adjusted maximum effort" or AMAX takeoff is designed for a plane to gain altitude as quickly as possible. The maneuver was created to cut down on the time insurgents on the ground could hit aircraft with small-arms fire and shoulder-fired weapons. The angle of takeoff and thrust are typically greater than in a normal takeoff.
But experts interviewed by the Air Force accident investigation board said that type of takeoff isn't needed when departing Jalalabad Airfield in eastern Afghanistan, where the crash occurred.
The cockpit voice recorder indicates Pierson wanted Golden to get more experience performing the maneuver, which has been deployed in other hot airfields around Afghanistan.
Pierson: "The rest is your brief. When you log it, don't log it as a max effort takeoff, so I don't get [redacted] questions about it, because you're not, co-pilots can't do max effort takeoffs. You know what I mean?
Golden: Yeah, I mean, it's your call.
The accident investigation board determined that Golden performing the maneuver had no effect on the crash, and data taken from before the accident show Golden was performing the takeoff correctly prior to the accident occurring.
"The AIB determined there were three causal factors and three contributing factors to the mishap, none of which were the co-pilot controlling the aircraft during takeoff," said 1st Lt. Elias Small, a spokesperson for Air Mobility Command. "The Mishap Co-Pilot was a current and qualified first pilot with 338.4 total C-130J hours, including 31.5 combat hours and 47.6 night-vision-goggles hours and was on track for upgrade to Aircraft Commander."
The high-power takeoff also didn't cause the crash, AMC said.
"Either an AMAX takeoff or a normal takeoff should have resulted in a safe flight if the flight controls hadn't been blocked," Small said. "However, with a normal takeoff, had the aircraft lifted off at 107.5 knots instead of 122 knots, it may have provided a more pronounced alert of the problem to the pilots, allowing them to abort the takeoff."
The cause of the accident was a night vision goggle case that Pierson placed to hold the control yoke in place, investigators said. This raised the rear elevators of the plane to give more space for the onload and offload of cargo.
But once it was time to take off, Pierson and Golden forgot to remove the case, investigators said, causing the elevators to be set at a dangerous angle upon takeoff — – one which caused the C-130 to pitch out of control shortly after leaving the ground.
In the cockpit voice recording, one of the loadmasters asks for the elevators to be raised.
Loadmaster: Hey, uh, do you mind raising up … what is it ... the elevator in the back?
Pierson: Yup, got it.
Loadmaster: Cool, thanks.
About seven minutes later in the recording, Pierson says he has his night vision goggle case holding up the yoke instead.
Pierson: Alright, my NVG case is holding the nose gear … or the elevator.
The C-130J was loading and unloading cargo at Jalalabad with its engines running, a procedure meant to keep the plane on the ground for as short a time as possible.
But unlike a takeoff involving a cold start-up of the engines, there's no preflight check in place to ensure that all control yokes have a full range of motion.
The pilot and co-pilot forgot about the case jamming the control yoke, investigators said, and didn't catch it with a pre-flight check. Plus, the accident investigation board said it was unlikely either pilot could see the case while wearing night vision goggles in the darkness.
"Air Mobility Command and the Air Force go to great lengths to ensure the safety of our airmen. We have briefed our aircrews on the importance of flight control motion checks after engine-running onload/offload operations," Small said. "Additionally, we are in the process of revising the engine-running onload/offload checklist and expect distribution in the immediate future."
With the control yoke holding the elevators at a slant, the pilot and co-pilot quickly lost control of the plane after takeoff and were unable to recover. The accident report estimates the plane impacted the ground at 14 degrees nose down, 28 degrees right wing down, at a ground speed of 87 knots and a vertical velocity of 8,000 feet per minute.
A team from Lockheed Martin — – which builds the C-130 for the Air Force — – analyzed the wreckage and determined that the plane was working fine until the crash.
"With the exception of the elevator … all aircraft systems were operating normally throughout the mishap sequence," the Lockheed report said.
