A1: The lamps with AS15 is one way interchangeable with ones that do not have AS15 after dash number; in other words, P/N MS25237-387AS15 can replace P/N MS25237-387, but P/N MS25237-387 cannot replace P/N MS25237-387AS15.
A2: Boeing has No Technical Objection (NTO) to use lamps without suffix AS15 as temporary replacement. Once lamps P/N MS25237-387 and P/N 387 are out of HNA’s current stock, P/N MS25237-387AS15, 387AS15, or M6363-8-7AS15 needs to be used on the LIGHT ASSY – PRESS TO TEST IND.