Military investigators are trying to determine whether glider operators followed proper protocols during a violent rain and windstorm last week at the Netook Gliding Centre that overturned and damaged at two craft and left three people injured.The approaching storm was threatening the centre at around 2 p.m. on Aug. 14. At the time eight people were out in the landing field by two grounded gliders away from the centre's hanger. When the storm began to produce high winds and pounding rain pilots and passengers began to tie down their crafts, which were on the runway, a kilometre from the centre's hanger.“The winds picked up and they couldn't hang on to the gliders. The wind was too strong, picked up the gliders and flipped one upside down. There was one occupant inside of it,” said Olds RCMP Const. Kurtis Milbrandt. “A girl that was hanging on to one of the wings of the glider got thrown. She fell to the ground when she let go. She was hanging on to one of the struts to keep it from flying out into the field.”Both gliders were blown off the runway and landed overturned 15 metres away in an adjacent field.A military spokesperson familiar with the centre's operations said the gliders are believed to be American-made Schweizer SGS 2-33 training models that weigh about 600 lbs. when not occupied.Immediately after the violent weather episode, police, fire and EMS personnel were dispatched to the centre.Milbrandt said one man, an adult instructor and pilot, was transported to Red Deer Regional Hospital Centre for treatment of a dislocated shoulder and a possible broken collar bone. A second man, who suffered a cut during the storm, and a woman were transported to Olds Hospital. They were treated and released.Milbrandt said the RCMP's investigation of the incident is completed. He said the file has now been sent to military authorities at the Penhold Air Cadet Summer Training Centre, which is responsible for the operations at the gliding centre. As the two gliders were grounded at the time of the violent weather episode there will be no investigation by Transport Canada, said Milbrandt.“We currently have an investigation underway. Investigators are at Netook today (Aug. 15). This will be an internal fact finding process,” said Lt.-Col. Allan Dengis, commanding officer of the Penhold cadet training centre. “We will determine if there was an adherence to our rules and regulations.Dengis said he did not know how long the probe would take.He said four of the eight people caught in the storm by the gliders were adults while the others were staff cadets.“They all have had training in their areas of responsibility working in the Netook gliding program,” said Dengis of their glider operational credentials.