WPR18FA232

The failure of both pilots to see and avoid a power line while maneuvering at low altitude. Contributing to the accident was the flight instructor's decision to not follow the training syllabus and allow the low-level high-speed flight.

The flight instructor was providing emergency procedure refresher training, as part of a contract between the US Army and a private contractor, to special operations pilots with the Jordanian Air Force. The accident was intended to be an introductory orientation flight for the pilot receiving instruction of the airports areas where the training would be occurring. Radar data indicated that the helicopter traveled east from the departure airport and climbed to an altitude of about 500 ft above ground level (agl). Afterward, the helicopter began to descend, and flew at altitudes that varied between 0 and 120 ft agl at a groundspeed of about 90 knots. A witness saw the helicopter rapidly approaching his location and reported that the helicopter was flying low in a nose-down attitude. A short time later, the helicopter struck and severed a steel wire power distribution line, and continued to fly until the helicopter impacted the ground about 950 ft beyond the impact point with the line. Most of the severed power line was continuous to the main wreckage location, having likely trailed or been attached to the helicopter after impact. According to the radar data, and impact trajectory, the 36-ft-tall power line support poles would have been hidden from the pilots' view by a stand of trees as the helicopter approached the area. Postaccident examination revealed no anomalies with the airframe or engine that would have precluded normal operation of the helicopter. The wreckage location, which was well beyond the impact point with the power line, was consistent with the helicopter operating at a high forward speed and likely a high engine power. The flight instructor was highly experienced in the accident helicopter make and model and had an extensive military career flying attack missions in helicopters. These missions included navigation and aerial gunnery, which would have required low-level flight close to terrain. Likewise, the pilot receiving instruction flew similar attack missions in helicopters with the Jordanian military. Therefore, it is likely that the flight instructor decided to intentionally deviate from the training syllabus and perform, or allow the pilot receiving instruction to perform, a high-speed, nap-of-the-earth flight for personal reasons, possibly to simulate their working environment, make the flight more interesting or engaging, push limits, or impress each other. The flight instructor had used the sedating antihistamine cetirizine at some time before the accident flight. Although the levels of the drug were well below the therapeutic range, it is not possible to determine if he could have been impaired by the sedating effects during the accident sequence.

According to the National Oceanic and Atmospheric Administration, the altitude of the sun when viewed from the accident site at 1218 would have been 64.6°, with an azimuth (east of north) of 133°. Flight Instructor The flight instructor had held operational and instructional pilot positions within multiple US Army regiments, including time as an attack helicopter pilot with the 160th Special Operations Aviation Regiment (SOAR). During that time, his flight duties included long-range navigation and precision aerial gunnery in the AH-6J "Little Bird" attack helicopter, which had a similar design as the accident helicopter and was based on Boeing's MH-6 "Little Bird" and MD Helicopters' 369-series helicopters. After retirement from the US Army and before his employment with Brunner Aerospace, the flight instructor held positions as a pilot, an instructor, and a manager at various aviation-related companies operating in Iraq and Afghanistan. The flight instructor was in his second year working for Brunner Aerospace as an instructor. He resided in Alabama and stayed in a hotel in Texas while he provided training. Pilot Receiving Instruction The pilot receiving instruction was a first lieutenant in the Jordanian Air Force Special Operations Command, for which he flew an MD530F helicopter that was designed and configured similarly to the accident helicopter. Brunner Aerospace indicated that the Jordanian pilots attend the training course each year and that the accident flight occurred during the pilot's second year attending the training. Instructor The Office of the Chief Medical Examiner, Tarrant County, Texas, performed an autopsy on the flight instructor. The cause of death was thermal trauma, and no significant natural disease was identified. Toxicology testing performed at the FAA Forensic Sciences Laboratory for the flight instructor detected tamsulosin, celecoxib, and cetirizine (0.043 µg/ml) in the pilot's specimens. Tamsulosin is used to treat an enlarged prostate, and celecoxib is a prescription anti-inflammatory medication. Neither is considered to be impairing. Cetirizine is an over-the-counter sedating antihistamine intended to treat allergy symptoms. The usual therapeutic range is 0.190 to 1.450 µg/ml. Although this drug can undergo postmortem redistribution, that would likely mean that the antemortem level was lower than the tested level. No carbon monoxide or ethanol was detected. The cause of death for the pilot receiving instruction was thermal trauma, and toxicology testing performed at the FAA Forensic Sciences Laboratory identified no carbon monoxide, ethanol, or for screened drugs. The accident helicopter was one of two 369FF helicopters that Brunner Aerospace operated as part of the flight training program. Avionics equipment installed on the accident helicopter included a Garmin 430 GPS/Nav/Comm and a radar altimeter. The doors had been removed for training. No discrepancies were noted on any of the helicopter's flight logs between the last inspection and the accident. On August 21, 2018, about 1218 central daylight time, a Hughes Helicopters 369FF, N530FU, was destroyed when it was involved in an accident near Granger, Texas. The flight instructor and the pilot receiving instruction sustained fatal injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. Brunner Aerospace had been contracted by the US Army Security Assistance Training Management Organization (SATMO), to provide "MD530F Emergency Refresher Training (Enhanced)" for special operations pilots who flew the MD-530F with the Jordanian Air Force. The accident flight was one such training flight. The flight originated from Georgetown Municipal Airport (GTU), Georgetown, Texas, about 1208 and was destined for Draughon-Miller Central Texas Regional Airport (TPL), Temple, Texas. About 1207, the flight instructor made a radio call to the GTU tower and reported his intention to depart to the northeast. The tower controller acknowledged the flight instructor's transmission and cleared the helicopter for departure. The final stage of the accident was not observed by any witnesses; however radar data from a Federal Aviation Administration (FAA) air route surveillance radar about 30 miles northeast of GTU revealed a target departing the GTU airport environment about 1209 and traveling east while climbing to a mode C transponder-reported altitude of 1,100 ft (about 500 ft above ground level [agl]). About that time, the instructor requested a frequency change with the tower, and 4 minutes after departure (9 miles east of Georgetown), the target began to descend. One minute later, the target had reached an altitude of about 50 ft agl. The target continued traveling east at a groundspeed of about 90 knots and at altitudes that varied between 0 and 120 ft agl over unpopulated areas. A witness, who was at his residence 2 miles southwest of the town of Granger, stated that although helicopters are a normal sight in the area, between 1200 and 1300 on the day of the accident his attention was drawn to the unusually loud sound of a helicopter. When the witness looked north, he observed a black helicopter rapidly approach his house from the northwest, flying low over a field, about 30 to 40 ft agl, in a nose-down attitude. The witness became concerned that the helicopter might collide with his house, and reported that just as the helicopter approached to within about 200 ft, it began to rapidly climb up and over the power lines that bordered his street. He then looked to the south and anticipated that he would see the helicopter, but it was out of his view behind a stand of trees. The radar data revealed that, about 1215:26, the target, while at 25 ft agl, had traveled left to right directly in front of the witness's house, coming within 700 ft. The target then began to climb and reached 125 ft agl as it passed beyond the witness' house while proceeding southeast. The last recorded target, which was 1 mile west of the accident site, was captured at 1217:14 at an altitude of 58 ft agl. The helicopter wreckage was located in a cotton field about 4 miles east of the witness' residence, and 1.5 miles west of Granger Lake. (as shown in figure 1). Figure 1. Radar track (as indicated by red line) and wreckage location. (Background image courtesy of Google Earth). A student pilot and a flight instructor in a fixed-wing airplane who were returning to GTU reported that, between 1215 and 1220, they both heard a series of expletives being transmitted over the GTU frequency in a manner that, according to the instructor, sounded "desperate." The student pilot stated that the transmissions lasted about 2 seconds, and the flight instructor stated that the transmissions happened just before he made his first call to GTU tower. The student pilot stated that he and the flight instructor were flying over Granger Lake (1.5 miles from the accident site) at the time. No such transmissions were heard on the GTU tower audio recordings. The first identified points of ground contact consisted of five matching 2-ft-long excavations that were equally spaced throughout a length of about 40 ft and were on a magnetic heading of 100°. The excavations contained fragments of yellow paint, which matched the paint color on the tips of the five main rotor blades. The cotton plants adjacent to the excavations had been sheared on a 45° plane relative to the ground. The debris field, which consisted of landing skid fragments, pieces of windscreen, cabin contents, and sections of a main rotor blade, continued for 100 ft on a heading of 080° directly to the main cabin. The cabin came to rest on its left side on a heading of about 280°. Most of the cabin was consumed by fire. The tailcone and tail rotor assembly had separated and were located about 20 ft east of the cabin. The debris field was bordered to the west b