Autogyro CALIDUS N623AG accident near Tacoma, Washington

Probable cause

The pilot's failure to properly configure the gyrocopter for takeoff, which resulted in it developing high speed and led to a subsequent loss of control.

NTSB analysis

While preparing for takeoff in the gyrocopter, the commercial pilot had difficulty getting the prerotator to engage with the rotor ring gear, so he aborted the takeoff attempt. He then taxied off the runway to a run-up area and successfully engaged the prerotator to the rotor ring gear. The pilot then taxied onto the runway, and the rotor reached 200 rpm, after which he began the second takeoff attempt. The pilot stated that he recalled pulling the control stick aft while the gyrocopter was accelerating down the runway. Subsequently, the gyrocopter suddenly began climbing and shaking violently. The pilot then lost control of the gyrocopter, and it descended, struck the runway, skidded about 100 ft, exited the left side of the runway, and then came to rest on its left side. A witness reported that the gyrocopter began the takeoff roll with the rotor level with the runway.

During an interview with the flight instructor who trained the pilot in the gyrocopter, she stated that, when engaging the prerotator for takeoff, it is essential to keep the control stick fully forward to protect the airframe from the slow-spinning rotor. A fully forward control stick would place the rotor level with the ground, as described by the witness. The rotor then needs to achieve 200 rpm, followed by the control stick being moved fully aft for the takeoff roll, tilting the rotor. Further, the Airplane Owner's Manual contained a warning stating that "Prior to releasing the wheel brake, make sure that the control stick is fully aft…A takeoff run with a flat rotor system may have fatal consequences."

Given the pilot and witness statements and that the gyrocopter skidded 100 ft after impacting the runway, it is likely that the pilot did not pull the control stick fully aft after prerotating the rotor to 200 rpm and conducted the second takeoff attempt with the control stick not fully aft and with the rotor level with the ground. The pilot’s failure to properly configure the gyrocopter for takeoff resulted in it developing high speed during the takeoff roll and the subsequent loss of control.

Text from the NTSB. Open the NTSB docket for WPR18LA190 for the full record.