Accident Overview
On February 1, 2019, at approximately 1355 mountain standard time, an experimental, amateur-built Rans S-12XL airplane, registration N536RH, was substantially damaged in an accident near Socorro, New Mexico. The pilot was fatally injured. The airplane was operating as a Title 14 Code of Federal Regulations Part 91 personal flight.
Flight History
Radar flight track data showed the airplane departed from runway 33 at Socorro Municipal Airport (ONM) and remained in the vicinity, completing multiple turns. The flight track ended about 1 mile northwest of the accident site. The airplane impacted a parked and unoccupied helicopter and a light pole before coming to rest in a vacant parking lot at ONM. No witnesses observed the accident. Witnesses in a nearby building heard the airplane’s engine at “high rpm” and the impact sequence shortly after.
Pilot Background and Aircraft Information
According to a family member, the accident flight was the pilot’s third flight in the airplane, and the pilot had a total flight time of about 25 minutes in that aircraft. The pilot had replaced various tubing, replaced the sparkplugs, and rebuilt both carburetors soon after purchasing the airplane. The family member further stated that the pilot was experiencing weight and balance and stability issues and had communicated with the aircraft manufacturer regarding the horizontal stabilizer position.
Weight and Balance Concerns
In an email to the manufacturer, the pilot reported that during the second flight the horizontal stabilizer was positioned to the lowest position. In response, the manufacturer stated that the airplane requires “a total weight of 260 lbs in the seats to fly proper,” adding “it is not your stab setting it is a lack of ballast” and “It is dangerous if out of CG.”
According to the Pilot’s Operating Handbook, Chapter 4 - Weight and Balance, if combined pilot and passenger weight is between 108 and 345 pounds, the center of gravity (CG) will be acceptable regardless of fuel conditions. However, flying at the aft CG limit requires adjustment of the horizontal stabilizer; as suggested by the test pilot, a solo pilot should use 50 or 75 pounds of ballast when operating the aircraft. Failure to do so will impose seven limits on the amount of nose down force available even with full forward stick. The CG envelope is defined between 69.5 and 76.5 inches aft of datum.
Wreckage Examination
Examination of the wreckage revealed no evidence of preaccident mechanical malfunctions or anomalies that would have precluded normal operation. The horizontal stabilizer was found at its lowest position. Two bags of ballast weight were found with the main wreckage and in the forward cabin area. The total weight of the ballast could not be determined due to loss of material from the damaged bags. An accurate weight and balance of the airplane could not be determined due to the unknown amount of fuel and damaged ballast bags onboard at the time of the accident.