If there is time, and other conditions are favorable the aircrew member should ensure that helmet straps are secure, the visor is down and locked, and the oxygen mask is fitted tightly. All harness straps should be tightened, and any loose equipment properly stowed. The aircrew should attempt to have the aircraft in a straight and level attitude at the time of ejection. If the aircraft is rolling and near the ground, ejection should be attempted when the plane is coming upright. However, ejection should not be delayed until the aircraft is out of the ejection envelope.
Body position is also extremely important.
The body should be erect with buttocks against the backrest, head firmly against the headrest, and thighs against the seat pan. A leg fracture may occur when an occupant ejects with one leg raised off the seat pan. While the time delay prior to ejection can be used to optimize ejection conditions, it has also resulted in numerous unnecessary fatalities. Many studies over the years have shown the danger of delaying too long. Over one-third of the aircrewmen fatally injured during ejection waited until the aircraft was below a safe ejection altitude before initiating their seat system.