Section 23.2435 - Powerplant induction and exhaust systems(a) The air induction system for each powerplant or auxiliary power unit and their accessories must-(1) Supply the air required by that powerplant or auxiliary power unit and its accessories under likely operating conditions;(2) Be designed to prevent likely hazards in the event of fire or backfire;(3) Minimize the ingestion of foreign matter; and(4) Provide an alternate intake if blockage of the primary intake is likely.(b) The exhaust system, including exhaust heat exchangers for each powerplant or auxiliary power unit, must-(1) Provide a means to safely discharge potential harmful material; and(2) Be designed to prevent likely hazards from heat, corrosion, or blockage.