WPR17LA186

The pilot’s loss of airplane control after flying through another airplane's jet wash during an air defense exercise.

The civilian airline transport pilot was conducting a cross-country flight with another airplane to participate in a military air defense training exercise. The accident pilot reported that, while flying about 14,000 ft mean sea level (msl), one of the military airplanes started flying alongside his airplane's right wing and then accelerated ahead of his airplane and crossed in front of its flightpath. The military pilot stated that he tried to get the accident pilot's attention so that he could make him aware of his position but that he was unsuccessful. The accident pilot reported that he attempted to follow the military airplane but that it then turned right and passed in front of his flightpath again. The accident pilot added that, as he turned right to follow the military airplane, he heard a "thump," which he attributed to jet wash. His airplane then immediately rolled left. He attempted to counter the left roll by applying right aileron, but the airplane then entered a nose-down attitude and began to spin. The pilot attempted to recover control without success, and he subsequently ejected from the airplane while it was passing through 4,000 ft msl. The airplane subsequently descended into the ocean. The airplane could not be examined after the accident because the wreckage was not recovered from the ocean. The pilot reported seeing that the magnetic indicators displayed black, which suggests that aileron hydraulic power was being supplied to the ailerons at the time of the loss of control. Given the evidence, it is likely that, after the accident airplane flew through the military airplane's jet wash, aileron movement was inhibited for reasons that could not be determined, which resulted in the pilot's loss of airplane control.

The pilot, age 44, held an airline transport pilot certificate with ratings for airplane single-engine land, multi-engine land, instrument airplane and a type rating for Hawker Hunter MK-58. His most recent Federal Aviation Administration (FAA) first-class medical certificate was issued on February 8, 2017, with no limitations. At the time of the accident, the pilot had accumulated 3,138 total flight hours; 420 of which were in the accident airplane make and model. The airplane impacted open water about 2 nm from its final radar data point. ATAC reported that the debris field was comprised of an oil slick, and no physical remnants of the aircraft. The airplane wreckage was not recovered. The airplane was manufactured by Hawker-Siddeley in 1959 and was originally designed as a single-engine, swept wing, tactical military aircraft, powered by a Rolls-Royce AVON 207, turbojet engine with a full functioning emergency ejection seat. At the time of the accident the airplane was owned by Hunter Aviation International, Inc. and operated by Airborne Tactical Advantage Company (ATAC) as an armed forces Public aircraft. The airplane's most recent conditional inspection was completed on May 11, 2017, at 3,242.6 hours total time in service. At the time of the accident, the engine had accrued about 323 total hours since its most recent overhaul, and a total of 41 flight hours since its recent conditional inspection. The airplane's flight logbook captured the reported maintenance deficiencies from January 2017 to the date of the accident. A reported deficiency from August 15, 2017 stated that the "aileron trim indication was found inoperative during pre-flight checks." As a result, the position transmission cable, trim motor bellcrank, and trim operating rod were replaced. Additionally, aileron travel was confirmed in accordance with AP101B-1307-1, Section 3, Chapter 4, Figure 11. On August 22, 2017, about 1618 Pacific daylight time, a Hawker Hunter MK-58, N338AX, was destroyed when it impacted open water about 80 nm southwest of San Diego, California during an exercise with a United States military fighter jet. The airline transport pilot received minor injuries. The airplane was registered to Hunter Aviation International, Inc. and operated by Airborne Tactical Advantage Company (ATAC) under contract with the U.S. Navy as a Public aircraft. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the local flight that departed Point Mugu Naval Air Station, Oxnard, California at 1517. According to ATAC, their pilots were participating in an adversarial mission in support of an air defense vulnerability period for Carrier Air Wing/ USS Theodore Roosevelt Carrier Strike group assets. The F-35s from the U.S. Air Force's 62nd Fighter Squadron would conduct a defensive counter air mission, while the MK-58s provide adversarial support. On the day of the accident, the accident pilot and his wingman, assigned as Red Air for the exercise, checked in with the Red Air controller and coordinator of the exercise to understand their roles and to obtain the correct radio frequencies. Their goal in the exercise was to overfly the military aviator's ships without being escorted. After an uneventful outbound flight to the theatre area the airplanes were escorted around the aircraft carrier. At times, two FA-18 turbojet fighter airplanes, piloted by naval aviators, would follow behind the pilot and his wingman while the controller issued instructions to observe the navy pilots' responses. The FA-18 fighters were then relieved by two F-35 fighters. While flying at 14,000 ft mean sea level (msl), one of the F-35s flew alongside and about 1,500 ft from the accident pilot's right wing. Moments later, the F-35 accelerated ahead of the pilot and crossed in front of his flight path from the accident pilot's right side to his left side. The pilot attempted to follow the F-35, but the airplane then initiated a right turn and passed in front of the pilot's flight path again, this time to the right. As the pilot started to turn right to follow the F-35, he heard a "thump", which he dismissed as jet wash. He continued his maneuver and rotated to the right into an approximate 60° angle of bank and began to apply back pressure, but the airplane immediately rolled into a left bank, at which time the F-35 disappeared from his view. The pilot briefly terminated the left-hand roll by applying right aileron but was unable to move the flight controls more than one inch to the right of its center position. He remarked that the right aileron flight control movement felt "jammed" as he can normally move the flight controls to his right knee. The airplane then entered an approximate 35° nose down attitude, at which time the pilot applied back pressure on the flight controls, but the airplane repeated its previous movement and entered a left-hand roll. After about 2 full 360° rotations, the pilot stopped the movement with some right aileron, but the flight controls still would not advance to the right more than one inch beyond its center position. As he was passing through 4,000 ft mean sea level, the pilot notified his wingman that he was ejecting. He did not observe any unusual sounds or harmonics from the engine during the accident flight. F-35 Pilot According to the trailing F-35 pilot, he was assigned to United States Air Force's 62nd Fighter Squadron to support an exercise for the United States Navy with the USS Theodore Roosevelt off the California coastline. During the briefing, he was informed that both he and his lead would be flying as "Blue Air"; their objective was to defend the south, intercept any adversaries coming from the north and escort them back to their airspace. The soft deck for the exercise was 10,000 ft and the hard deck was 5,000 ft. After an uneventful departure, the pilot of an F/A-18 informed the F-35 pilot and his lead that he had rejoined, maintained close visual formation inside of 1,000 ft, on a pair of Hawker Hunters, and asked the F-35s to rejoin on them. The F-35s started to rejoin on the Hawker Hunters as the F/A-18s ceased their engagement of the adversarial fighters. The lead F-35 pilot covered the trailing Hawker Hunter, while the trailing F-35 pilot advanced forward of the lead Hawker Hunter and rejoined off the lead pilot's left wing. The trailing F-35 pilot rocked his wings and the Hawker Hunter pilot acknowledged. After the F-35 pilot informed the controller that the Hawker Hunters were continuing north and the F-35s were going to cease their engagement, the Hawker Hunters reversed course and followed them to the south. The trailing F-35 pilot rejoined on the accident pilot about 500-800 ft off his right wing and rocked his wings, but the accident pilot did not acknowledge. After another unsuccessful attempt to get the accident pilot's attention, the trailing F-35 pilot accelerated ahead and high of the accident pilot and then descended as he crossed in front of the accident pilot's flight path from right to left and then reversed his turn (from left to right). He estimated from looking over his shoulder that he was about 2,500 ft in front of the accident pilot about this time and slightly higher. Following about 90° of turn and a snap roll the accident pilot appeared to be lining up a gun shot. The accident airplane then rolled inverted in a nose high attitude, which was followed by a snap roll and then a descending right-hand turn. His altitude at the time was approximately 9,500 ft. The airplane subsequently entered a dive, at which time the F-35 pilot engaged him with a simulated ordinance. The accident airplane never recovered from the dive. Radar data was provided by the Southern California Offshore Range (SCORE) at Naval Air Station North Island, California. The F-35's relayed altimeter data at a 1 hz sampling rate along with its geographic positioning system (GPS) data. Large Are