FLITECAM is a facility class instrument on SOFIA, operating form 1-5 microns. A 1024 by 1024 InSb ALADDIN II array will be used in a fully refractive optics system that provides three optical modes; imaging at a plate scale of 0.47 inch by 0.47 inch per pixel and afield of view of 8 feet, grism spectroscopy with moderate resolutions of about R equals 1000- 20000 depending on the slit width used, and a pupil viewing mode. The plate scale is achieved by using an f/4.8 back-end camera behind an f/4.9 collimator. The 8 foot field of view of SOFIAs f/19.6 telescope translates to a focal plane aperture of 114mm. The collimator optics are therefore quite large with a diameter of almost 170mm. Between the pupil image produced by the collimator and the f/4.8 camera, a ste of three lense will be inserted to achieve a pupil viewing mode. The optical train is entirely refractive, with triplets or split triplets using combinations of LiF, BaF2, ZnS, and ZnSe. The design of an optics system with this wide a wavelength range of more than two octaves and the large field of view present a challenging project. We demonstrate that our optical design meets the performance requirements with certain allowed lens-fabrication and misalignments built in.