Galactic cosmic rays produce high-energy radiation fields in the atmosphere at aircraft altitudes. Energetic particles generated on the sun also bombard the earth from time to time. These particles also produce radiation fields at aircraft altitudes which have qualitatively the same properties as atmospheric cosmic rays. We have used transport theory to calculate atmospheric cosmic-ray quantities for verification and equivalent doses to aircraft crews. We have also calculated radiation doses from several large solar energetic particle events which took place in 1989. The spectra incident on the atmosphere were determined assuming diffusive shock theory.