Dale Crane's Oral and Practical Exam Guide: Airframe questions with correct answers

Where does the warm air come from that is used to heat the cabin of most small single-engine reciprocating-engine-powered aircraft? CORRECT ANSWER -From a shroud around the engine muffler -Most single-engine light aircraft use exhaust shroud heating systems to heat the cabin. Ambient air is directed into a metal shroud, or jacket, that encases part of the engine's exhaust system. The air is warmed by the exhaust and directed through a firewall heater valve into the cabin. This simple solution requires no electrical or engine power and it makes use of heat that would otherwise be wasted. (FAA-H-8083-31, Vol. 2, Ch. 16) What is the danger of a leak in an exhaust system cabin heater? CORRECT ANSWER Exhaust gases contain carbon monoxide (CO), a colorless, odorless, gas the can cause incapacitation or death to the aircraft occupants How can an exhaust system be checked for leaks? CORRECT ANSWER Pressurize it with the discharge from a vacuum cleaner and wipe the outsider of the system with a soap solution. Any leak will cause bubbles to form How can you tell that there is carbon monoxide in the aircraft cabin? CORRECT ANSWER Indicator crystals in a CO detector will change color, from a normally bright color to a dark color. At lethal level of CO they will turn black Where does the fuel used in an aircraft combustion heater come from? CORRECT ANSWER From the aircraft fuel tanks What happens to a combustion heater if the flow of ventilating air is restricted? CORRECT ANSWER If the ventilati