On March 23, 2026, about 1221 eastern daylight time, a Robinson R44 Raven I helicopter, N478AT, was destroyed when it was involved in an accident near Boynton Beach, Florida. The flight instructor and the pilot receiving instruction were fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the flight school, Palm Beach Helicopters, the flight instructor, who was seated in the left seat, and the pilot receiving instruction, who was seated in the right seat, departed the Palm Beach County Park Airport (LNA), Latana, Florida, at 1124. The purpose of the flight was to provide the pilot receiving instruction with a basic visual flight rules (VFR) orientation flight, which was to include going to the Downtown Fort Lauderdale Heliport (DT1) in Fort Lauderdale, Florida, and then returning to LNA. Records indicated that 23 gallons of fuel was added to the helicopter just before departure and that the total amount of fuel onboard was 46.5 gallons. The helicopter was equipped with ADS-B, which provided helicopter position information, as well as SPOT Trace, which enabled both flight tracking and two-way text communication. According to the ADS-B data, the helicopter departed LNA and flew south along the coastline and conducted a landing at DT1. After departing DT1, the helicopter flew northwest, then made a turn back to the east. A review of archived voice communication information from the LNA common traffic advisory frequency (CTAF) revealed that the flight instructor first reported their position to be “7 [miles] to the south, straight in for [runway] 34.” About 27 seconds later, the flight instructor made another radio call and reported to a company helicopter that “we’re going to be landing out here in one of these fields, we’ve got something going on with the helicopter.” About 12 seconds later, the company helicopter attempted to contact N478AT, but they did not respond. Witnesses reported seeing the helicopter flying low before it suddenly entered a steep right turn with a nose-low attitude. Subsequently, the helicopter impacted the roof of a vacant warehouse about 6 miles south of LNA and came to rest inverted inside the building. During the impact sequence, the helicopter severed a water line for the building’s sprinkler system, dispersing a large amount of water on the wreckage. There was no postaccident fire. The main rotor and main rotor gear box were found suspended within the warehouse roof structure, and the main wreckage came to rest inverted below it. The engine core was found in the main wreckage behind the cockpit with the forward engine mounts separated and the aft mount still secured to the airframe. The tailboom was found secured to the airframe, and the tailrotor and empennage were found impact separated and within the main wreckage (see figure 1). Figure 1. Main wreckage inside vacant warehouse. During the NTSB’s on-site examination of the main rotor flight controls, the upper right push-pull tube was found separated from the lower rod end (part number D173-2), which remained attached to the upper hydraulic servo piston shaft at the clevis (part number D200-1). The palnut and jam nut that secure the upper right push-pull tube to the rod end could not be rotated by hand on the rod end threads. The upper right push-pull tube was observed to be elongated at the threaded end (see figure 2). Remnants of torque stripe paint was present on the push-pull tube, palnut, and jam nut. Figure 2. Upper right and left push-pull tubes and rod ends. The palnuts and jam nuts on the left and aft lower rod ends (part number D173-2) and below the hydraulic servo clevis were found to be finger tight. Varying degrees of corrosion was observed on the palnuts and jam nuts. Examination of the engine did not reveal any mechanical anomaly or malfunction that would have precluded normal operation. A review of the airframe maintenance records showed that the most recent maintenance was a 100-hour inspection, which was completed on March 23, 2026, at an airframe total time of 7,486.6 hours and a tach time of 3,091.1 hours. The most recent annual inspection was completed on June 18, 2025, at an airframe total time of 7,090 hours and a tach time of 2,694.7 hours. At the time of the accident, the tach time was 3,092.08 hours, and the engine total time since overhaul was 894 hours. The flight instructor held flight instructor and commercial pilot certificates with a rating for rotorcraft helicopters, a ground instructor certificate, and a remote pilot certificate. He held a first-class medical certificate issued April 2, 2025, without limitations. According to pilot records obtained from the flight school, the flight instructor had about 822 total hours of civilian flight experience and about 140 hours in the accident helicopter make and model. The pilot receiving instruction held an airline transport pilot certificate with a rating for airplane single-engine land and a commercial pilot certificate with ratings for airplane single-engine land, rotorcraft helicopter, and instrument helicopter. He held a first-class medical certificate issued February 28, 2026, with the limitation, “Not valid for any class after [February 28, 2027]. Must use corrective lens(es) to meet vision standards at all required distances.” On his application for the medical certificate, the pilot reported 5,725 total hours of civilian flight experience and 225 hours in the preceding 6 months. The three hydraulic servos, push-pull tubes, and rod ends were transported to the NTSB Materials Laboratory, Washington, D.C., for additional examination.