Flight Design CTLS N81KK accident near Palatka, Florida

Probable cause

The pilot’s improper management of his fuel supply, which resulted in fuel exhaustion and a total loss of engine power. Contributing to the outcome was the improper maintenance of the airplane’s ballistic recovery parachute system, which resulted in its failure to properly deploy. Also contributing, was the pilot’s failure to maintain the proper glide speed through the subsequent forced landing.

NTSB analysis

The pilot reported that the cross-country flight was uneventful until he was approaching the destination airport from the north, when the engine lost total power. He was unable to restart the engine and prepared for a forced landing in a clearing. He deployed the airplane’s Ballistic Recovery System (BRS); the rocket fired, but the parachute remained in its container. During the forced landing, the airplane was substantial damage and the pilot and passenger were seriously injured.

The pilot reported that he began the flight with about 13.5 gallons of fuel on board, which was consistent with the recorded fuel quantity remaining indicated by the airplane’s engine monitoring system (EMS); however, this value was not directly measured and depended on pilot input. There was no odor of fuel or evidence of fuel leaks at the crash site. The fuel tanks were not compromised during the impact and no fuel was found in the fuel tanks during recovery.

The engine and fuel system were examined after the accident and a test run was performed. The engine ran normally on the airframe and no evidence of a preexisting mechanical failure or anomaly was found. Examination of the EMS data revealed that, during the power loss, fuel flow increased to more than twice the normal rate. According to the engine manufacturer, air introduced into the fuel system due to fuel exhaustion can result in a fuel flow increase due to the impeller on the fuel flow transducer speeding up. Given this information, it is likely that the initial fuel-on-board indications were incorrect (as they were not indications, but calculations based on pilot input) and that the loss of engine power was the result of fuel exhaustion.

An examination of the BRS revealed numerous conditions that were indicative of improper or nonexistent maintenance and inspections. These conditions, among others, included the following. The S-folded harnesses were improperly secured inside the egress panel. These harnesses improperly protruded into and blocked the egress opening. They also protruded into and blocked the opening of the parachute canister. During the attempted BRS deployment, a portion of the egress panel remained attached to the airframe due to improper bonding. This condition blocked the parachute container, caused the rocket to deflect from its intended trajectory and resulted in the failure of the parachute to deploy.

The unairworthy condition of the BRS would have been prevented with proper preventative maintenance and use of the pilot’s preflight inspection procedures for the BRS. A review of the aircraft maintenance logbooks showed no compliance with an airframe manufacturer’s service bulletin that would have corrected these conditions if properly accomplished. Also, several of the airworthiness issues with the BRS could have been captured if the pilot’s preflight procedures for the BRS had been properly performed.

Finally, the EMS data revealed that the pilot allowed the airspeed to decay below best glide speed during the final minute of flight before ground impact. Thus, the vertical speed of the airplane increased and most likely resulted in greater damage and injury versus maintaining best glide speed throughout the forced landing.

Text from the NTSB. Open the NTSB docket for ERA19LA141 for the full record.