The enhanced radiation associated with solar particle events and in particular the secondary ionization doses created by the neutron flux in the upper atmosphere resulting from both cosmic ray and solar particle interaction with constituents of the atmosphere, pose an additional significant risk to both aircrew and passengers at aircraft altitude. Whilst the elevated x-ray component from a solar flare or coronal mass ejection (CME) can be significant, the effects of large particle events to the secondary radiation environment at jet aircraft cruising altitudes, can have consequences for both people and micro electronics used in modern generation aircraft. It has been shown that dose rates increase with higher latitudes and altitudes, and due to the geomagnetic field effect that deflects incoming solar and galactic cosmic rays, we get greater shielding closer to the equator. Generally increasing latitude appears to have a greater effect on increasing secondary radiation than altitude alone and this is certainly so during a solar flare or solar particle event.