This document contains five alternative approaches to the development of standards for emissions from T5 class aircraft engines. Four of these approaches attempt to comply with EPA's earlier stated intention to set standards as stated in the Preamble to Aircraft Standards, FR Vol. 38 No. 136 19088. Three of these approaches are found faulty by not imposing on the T5 class 'the same types of combustor design technology, as will be required of subsonic aircraft'. The fourth approach satisfactorily imposes the implementation of a common, acceptable technology. A fifth approach is investigated which attempts to set standards which are compatible with the constraint of requiring compliance in 1979 or shortly thereafter.