Loose Elevator Plug Jammed Controls in Rob Holland MXS Crash at Langley AFB

The National Transportation Safety Board (NTSB) released its final report on July 2 detailing the cause of aerobatic pilot Rob Holland’s fatal accident on April 24, 2025, at Langley Air Force Base. The investigation concluded that a loose elevator counterweight plug jammed the airplane’s flight controls, leading to a loss of control during landing. This finding finalizes and confirms earlier suspicions about damage to the customized elevator counterweight system causing the mishap.

Rob Holland was flying his MXS aerobatic aircraft from Smyrna, Tennessee, to perform at the Air Power Over Hampton Roads airshow. Witness testimonies and flight data recovered from the accident revealed that the airplane executed a stable approach to Runway 08 and maintained steady flight roughly 50 feet above ground level. However, the airplane subsequently pitched up and down multiple times before climbing and rolling left 90 degrees, then descending rapidly into the ground, resulting in the fatal crash.

Investigators discovered the left elevator counterweight plug approximately 10 feet behind the main wreckage. The plug bore gouges and paint transfers consistent with contact damage. Similarly, the horizontal stabilizer surfaces exhibited dents and scrub marks corresponding to the plug’s imprints. Laboratory analysis showed that the plug’s markings matched a nearby washer and screw, indicating repeated and damaging contact between these components during flight.

The elevator system involved was equipped with an adjustable balance tube, a modification that Holland requested during construction of the MXS. MX Aircraft, the manufacturer, described the counterweight plugs used as a provisional solution without providing continued airworthiness instructions or torque specifications for installation. The original design required an O-ring as a secondary locking mechanism, but investigators found no such O-rings on the plugs recovered from the wreckage, nor were the parts consistent with the original design dimensions.

The NTSB’s probable cause statement ascribes the accident to the loosening of a counterweight plug in flight that jammed the elevator control surface, thus causing a loss of control during the critical landing phase. This mechanical failure prevented proper pitch control inputs from being executed, ultimately resulting in the aircraft’s uncontrollable descent.

Following the accident, MX Aircraft issued a mandatory safety notice addressing MXS and MX2 models fitted with adjustable balance tubes. The directive recommended removing the adjustable counterweight setup and replacing it with a solid fill of lead-and-resin mixture to prevent similar malfunctions. This change aims to enhance reliability and avoid plug loosening and elevator jamming in the future.

Rob Holland, aged 50 at the time of the accident, was a highly respected pilot in the aerobatic and airshow community. He held an airline transport pilot certificate and reported more than 15,000 total flight hours. His accolades included winning six World 4-Minute Freestyle championships and 13 consecutive U.S. National Aerobatic Championships. Holland’s talent and contributions had earned him a reputation as one of the most inspiring aerobatic pilots in aviation history.

Rob Holland Aerosports released a statement mourning the loss of a great pilot and competitor. The accident and the NTSB report serve as a sobering reminder of the critical importance of mechanical integrity in aerobatic aircraft control systems, particularly in highly customized builds where standard manufacturer instructions may be limited or absent.

The new safety directive from MX Aircraft signals a push toward eliminating adjustable counterweight plugs in the affected aerobatic models. This incident underlines the need for rigorous adherence to design specifications and the potential hazards when temporary parts are employed without extensive airworthiness guidance.