Human error caused F-15E crash
By Kenneth Fine
Published in News on December 2, 2009 12:15 PM
Air Force officials released Tuesday a detailed report from an Accident Investi-gation Board convened shortly after a Seymour Johnson Air Force Base F-15E Strike Eagle crashed in Afghanistan July 18.
And the six-man board -- an F-15E pilot, physiologist, medical doctor, legal adviser, maintenance officer and Brig. Gen. H.D. Polumbo -- concluded that many factors led to the incident that left two 4th Fighter Wing officers, 336th Fighter Squadron Capts. Mark McDowell and Thomas Gramith, dead.
But their findings had a common thread: Human error.
McDowell and Gramith were on their way back to Bagram Airfield from a close-air-support mission when their flight lead, another 336th F-15E crew, who were not identified, decided to practice a maneuver Polumbo characterized as "very difficult": a high-angle strafe, an air-to-surface attack during which two-man Strike Eagle crews fire 20mm rounds at targets on the ground.
"Night high-angle strafe in mountainous terrain with night vision goggles is one of the most difficult and challenging events that any of these crew members would ever do in their entire career," Polumbo said. "So they were practicing that because it was important to support our men and women engaged in combat operations on the ground there in Afghanistan."
But the flight lead miscalculated the target altitude and McDowell and Gramith failed to cross check the information. So as they approached the target -- a dry lake bed just west of the country's Ghazni province -- at 470 knots, they had no idea they were closing in on the rough terrain below.
Polumbo said some three seconds before the jet crashed, the aircraft's ground collision warning system alerted the crew to "pull up," but that no attempt to do so occurred.
McDowell and Gramith died on impact, seconds before they were to open fire on their target.
Five factors "substantially" contributed to the mishap, Polumbo's report said: Misperception of the operational conditions in the target area, an erroneous expectation for a typical night strafing attack, inexperience by the flight lead and the fallen crew at executing night strafing, channelized attention and an improper cross check during the attack.
So in the weeks since the tragedy occurred, Air Force officials have been reviewing ways to prevent such an event from happening again.
That review has involved more than four months of research aimed at recreating the scene that unfolded that night -- interviews with comrades of the fallen stationed at Bagram Air Base, a thorough study of video and cockpit recordings of the flight and a ride in the 4th's Strike Eagle simulator.
But Polumbo was quick to point out that the crew was not, in fact, acting against the wishes of their commander -- that Strike Eagle crews practicing the maneuver is to the advantage of troops on the ground.
"The ways in which they had chosen to increase and maintain their proficiency in high-angle strafe was two-fold. One was to continue to get briefings from subject matter experts, especially in the Strike Eagle community ... on how to precisely use the 20mm Gatling gun in mountainous terrain, especially at night," the general said. "And secondarily, they were instructed by their commander to do practice strafing events at the end of actual combat missions when fuel and conditions permitted."
So even though mistakes were made that night, it is possible, he said, that F-15E aviators currently stationed at Bagram are practicing -- and using in troops-in-contact scenarios -- that same maneuver during their own deployment.
All who are deployed, Polumbo added, are qualified to execute high-angle strafing.
"It was just very much a tragic mistake that wasn't caught, but it wasn't due to lack of training," he said. "There were numerous opportunities in the two-ship formation's approach to the target area ... to recognize the elevation of that terrain ... as over 10,000 feet. All four crew members had the chance to look again."
Even as the aircraft was about to impact the ground, there was an opportunity to prevent loss of life, he added.
"We determined that on the first indication of impending ground collision, had the crew immediately recovered the aircraft, they would have recovered above the terrain," Polumbo said. "All four members of the two-ship formation did miss ... information that both aircraft correctly provided them."
So as the investigation points to human error, few changes will be made as a result of the incident.
Training procedures for all aviators are under review and commanders in Afghanistan have been briefed, but the F-15E -- and the men and women who command the Air Force's fleet of them -- will still be an essential part of operations in the country.
"This unfortunate accident will have no effect on what's going on at Seymour Johnson with the F-15E. It's a fantastic weapon system, one that the USAF relies on heavily," Polumbo said. "The value of the F-15E, and more importantly, the skill and dedication of the crew members, especially from Seymour Johnson, will be important to the United States Air Force and our joint operations for years to come."