In recent years, the development of high performance Spectral fibers has received increasing attention in industry. Because of the outstanding capability to absorb energy, these polyethylene fibers are frequently used in damage tolerant composite materials to protect equipment, apparatus, and/or people against blast and debris of explosion or projectiles. Since the fiber is thermally stable, it is possible to design composite structures that are suitable for use in applications where prolonged exposure to flame is anticipated. In this paper, we report the findings obtained in a recent flammability evaluation of a Spectra composite subjected to a torch flame, and to hot metal balls. The Spectra composite structures that will be discussed were found to withstand these exposures without burning and the smoke generation and toxic gas emission were far below the limits set in the standard for current aircraft interior materials.