An F-15C Eagle fighter jet assigned to the 44th Fighter Squadron, 18th Wing crashed last year due to a pilot error during training sortie with an F-22A, according to an accident investigation board report released Tuesday.
The F-15C and F-22A aircraft were over the Pacific for a routine sortie to practice simulated air-to-air missile engagements, according to the investigation.
According to a report released by the Pacific Air Forces, on 11 June 2018, at approximately 06:17 hours local time, F-15C, T/N 84-0008, assigned to the 44th Fighter Squadron, 18th Wing, Kadena AB, Japan, crashed into the Pacific Ocean approximately 70 miles south of Kadena Air Base. The aircraft was flying as a lead of a two-ship formation during a dissimilar basic fighter maneuver sortie with an F-22A, assigned to the 525th Fighter Squadron.
Investigators say the pilot had entered a negative G departure leading to a spin that was unrecoverable.
“While maneuvering defensively in relationship to the Mishap Wingman (MW), at approximately 5,400 feet mean sea level (MSL) and 180 knots indicated airspeed (KIAS), the MP initiated a vertical climb to 65 degrees nose high, 20 degrees of right bank, 39 degrees Angle-of-Attack (AOA), and 1.2 Gs, which apexed near 6,300 feet MSL and 105 KIAS, before a significant nose drop occurred,” said in report.
This resulted in a dramatic change in G-forces, from 1.2 Gs to -0.3 Gs, which caused the F-15 to go into “a negative G departure from controlled flight.”
The accident investigation board president found that the crash was caused by the pilot’s improper application of the stick forward, with full right rudder, which caused the plane to simultaneously yaw and roll and depart from controlled flight.
Col. Harmon S. Lewis Jr., the Accident Investigation Board president, also determined that “three additional factors substantially contributed to the mishap: spatial disorientation, lack of emergency procedure training for negative G departures from controlled flight, and limited time to analyze the situation and recover.”
As for the F-22, it received no damage and returned to the base.