FAA Oral Powerplant ( ASA, JEPPESEN ) Questions and answers.

1. Reciprocating Engines Oral (2-26) How are conventional reciprocating engine classified? They are classified by cylinder arrangement(v-type, in-line, radial, and opposed), or method of cooling (liquid cooled, or air cooled). Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:00 / 0:15 Full screen What are the different types of piston rings? Compression rings, Oil control rings, and Scraper rings. What are the main causes of a cylinder having low compression Broken piston rings, rings that are not seating properly, brunt valves, and poorly seating valves. What is the purpose of the oil control rings? They are used to control the thickness of the oil film on the cylinder walls. What may be the result of installing piston rings incorrectly? Excessive oil consumption. What type of piston rods are commonly found in radial engines? A master and articulating rod assembly. What type of bearings are in general use in reciprocating engines? Plain, roller, and ball bearing. What is the indication of valve blow by? It is indicated by hissing or whistle sound. What is the purpose of using more than one spring for valve closing? It is used for Eliminating valve float. What is the purpose of valve overlap? It is for better volumetric efficiency and lower the cylinder operating temperatures. Describe the inspection you would give the valve springs during engine overhaul. They should be cleaned thoroughly, then visually inspected for evidence of overheating, cracks, broken ends, and compression strength. What is the purpose of using valves with sodium filled stems? The sodium is an excellent heat conductor. What causes engine sudden stoppage? Striking an object or internal damage. What type inspection must be made after sudden stoppage of an engine? Complete engine tear down and inspection. What is the purpose of the crankshaft dynamic dampers used in aircraft engine? It is for overcome forces which cause deflection of the crankshaft and torsional vibration. How would you make a "runout" check on a crankshaft that is still installed in the engine? Rotate the crankshaft and check for misalignment. What is detonation? Instantaneous explosion. What cylinder is engine to magneto timing based on? The number one cylinder. What is engine sudden speed reduction? When the propeller strikes an object but continues to run. What can be learned about the condition of an engine by studying the results of a compression check? Determine if the valves, piston rings, and pistons are adequately sealing the combustion camber. How can a cold cylinder be located on a double row radial engine? They can be checked by a cold cylinder indicator. What instrument can be used to check bore for out of roundness? Dial indicator, telescopic gauge, outside or inside micrometer. What would a cold cylinder indicate? It means no combustion inside the cylinder Where is a crack most likely to occur on a piston? Where the piston pin connects. What should be done to nosewheel airplane before removing the engine? Support the tail of the airplane. 2. Turbine Engines Oral 28-46 What are the major components of a typical gas turbine engine? Air inlet, compression section, combustion section, turbine section, exhaust section, and accessory section. What are the two principle types of compressors used in turbojet aircraft? Centrifugal flow type and axial flow type. What are the four combustion chamber systems? Can, can-annular, annular, reverse flow annular types. What is the purpose of the interconnector tubes between can type combustion chambers? To spread the flame to the combustion chambers. What prevents burning of the liner walls in can type combustion chambers? Louvers provide cooling layer of air along the inside wall. What types of damage may be found when inspecting compressor blades? Dents, scratches, gouges, galling, burns, pitting, and cracks. What is the location and function of the diffuser section in a turbine engine? It is between compressor section and burner cans. It reduces the airflow and improve the combustion efficiency. Where are stress rupture cracks most likely to occur on turbine blades? Hairline cracks on the leading edge and trailing edge of the blades. How are compressor blades attached to a disk-type rotor? Bir-tree type, bulb type, dove tail type. What is the purpose of the nozzle diaphragm, or turbine nozzle? Change the heat and pressure energy to velocity energy. Make maximum turbine rotation. What is the major difference between turboprop and turbojet engines? Turboprop as more turbine stage and drive propeller. What is a turbofan engine? Same as a turboprop except the propeller is duct-fan. What is the effect of air density on the thrust of a turbine engine? If density increase, thrust increase. If density decrease, thrust decrease. Increase temperature, density decrease.