LAMMERS SJEF J APACHE
Colorado Springs, CO — May 20, 2011
Event Information
| Date | May 20, 2011 |
| Event Type | ACC |
| NTSB Number | CEN11CA360 |
| Event ID | 20110531X94940 |
| Location | Colorado Springs, CO |
| Country | USA |
| Coordinates | 38.94056, -104.40195 |
| Airport | Meadow Lake |
| Highest Injury | SERS |
Aircraft
| Make | LAMMERS SJEF J |
| Model | APACHE |
| Category | WSFT |
| FAR Part | 091 |
| Aircraft Damage | SUBS |
Conditions
| Light Condition | DAYL |
| Weather | VMC |
Injuries
| Fatal | 0 |
| Serious | 1 |
| Minor | 0 |
| None | 0 |
| Total Injured | 1 |
Event Location
Probable Cause
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
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 hanger 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 and 150 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.
About This NTSB Record
This aviation event was investigated by the National Transportation Safety Board (NTSB). NTSB investigates all U.S. civil aviation accidents to determine probable cause and issue safety recommendations to prevent future accidents.