NTSB Identification: CEN11CA360
14 CFR Part 91: General Aviation
Accident occurred Friday, May 20, 2011 in Colorado Springs, CO
Probable Cause Approval Date: 10/06/2011
Aircraft: LAMMERS SJEF J APACHE, registration: N566RL
Injuries: 1 Serious.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

On the morning of the accident, the pilot had removed his single-surface wing and installed a dual-surface wing on his weight shift aircraft. The winds were calm and he conducted an uneventful test flight. The pilot returned to his hangar and made some adjustments to the control bar but elected to not do another test flight because the winds were increasing at the airport. Later that afternoon, the pilot decided to do a second test flight because the wind had decreased some. The pilot departed with an 80 degree crosswind between 5 and 10 knots. He said that he did not build up sufficient airspeed on the takeoff roll and once he got airborne he was about 5 knots above stall speed and very slow. When the aircraft was approximately 100 feet in the air, he encountered wind shear and the right wing stalled and dropped. The pilot was unable to recover and the aircraft crashed on the right side of the runway, resulting in substantial damage to the entire aircraft.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot's failure to maintain control of the aircraft during take-off in a cross wind, which resulted in an inadvertent stall.

Full narrative available

Index for May2011 | Index of months