Q515 - Gas Turbine Plants, USCG prep certification 2026

Progress: 24% (23/94)

Learning progress ?

1. Active corrosion on copper alloys is indicated by which of the following?Not learned 2. What are the two common forms of axial compressor rotor blade roots?Not learned 3. How do the high-velocity high-temperature gases cause the gas turbine rotor to rotate?Not learned 4. Before combustion can occur, the combustion air must be delivered to the combustor at a high-pressure and low-velocity. High-velocity, low-pressure air is converted to high-pressure, low-velocity air at what part of a centrifugal type compressor?Not learned 5. Which of the following is an advantage of a single-shaft gas turbine engine compared to a split-shaft gas turbine engine?Not learned 6. What type of air seal is used in the sump and turbine areas of a gas turbine engine?Not learned 7. What type of air seal is used in the combustor and turbine midframe of a gas turbine?Not learned 8. What type of seal is used in the gearbox of a gas turbine engine?Not learned 9. The main thrust bearing directly positions which part(s) of the main reduction gear?Not learned 10. What type of main reduction gear arrangement prevents independent axial and rotational movement of the pinions?Not learned 11. The purpose of the main reduction gear in a marine gas turbine propulsion installation is which of the following?Not learned 12. What does the term "lock-out" of a synchro-self-shifting (SSS) clutch system meanNot learned 13. What is the purpose of the GE LM2500 gas turbine enclosure heater?Not learned 14. How many shock mounts are used to secure the GE LM2500 gas turbine enclosure to the ship's foundation?Not learned 15. Where are the carbon dioxide nozzles located in the GE LM2500 gas turbine enclosure?Not learned 16. The gas generator section of the GE LM2500 gas turbine is composed of all of the following components EXCEPT which of the following?Not learned 17. The struts of the GE LM2500 compressor front frame provide passages for all of the following mediums EXCEPT which of the following?Not learned 18. What is the primary purpose of the diffuser and distributor on the GE LM2500 gas turbine?Not learned 19. Which of the following components prevent(s) objects smaller than 1/4 inch from entering the GE LM2500 gas turbine?Not learned 20. How is the HP turbine rotor of the GE LM2500 gas turbine cooled?Not learned 21. For the GE LM2500 gas turbine shown in the illustration, the 9th stage bleed air is used for which of the followingNot learned 22. As shown in the illustration, the HP turbine 2nd stage blades are cooled by convection, with the cooling air being discharged at which of the followingNot learned 23. Boyle's law can best be defined as _________.Not learned 24. The term used to describe a gas turbine in which air drawn from the atmosphere passes through the engine only once is which of the following?Not learned 25. A gas turbine that has a regenerator between the compression and combustion sections in which exhaust gas heat energy is added to the air charge is classified as what type of engine?Not learned 26. The term used to describe a gas turbine in which the turbine exhaust passes through a cooler and back to the compressor inlet is which of the following?Not learned 27. In a regenerative or recuperative gas turbine cycle configuration, the heat of the turbine exhaust gas is used to do what?Not learned 28. What design feature is incorporated into the main propulsion gas turbine to eliminate compressor surge?Not learned 29. The secondary passages on the gas turbine engine fuel nozzles shown in the illustration are designed to open at approximately what pressureNot learned 30. On a gas turbine powered vessel equipped with a synchro-self-shifting (SSS) clutch, you are preparing for a power turbine overspeed test. What would be an important action to take prior to starting the engine?Not learned 31. Aboard ship, single-shaft gas turbines are used mostly as prime movers for which of the following applications?Not learned 32. You are on watch on a gas turbine propelled vessel as shown in the illustration. After reducing power in response to a high lube oil supply temperature alarm, the temperature continues to increase. Your next step should be which of the followingNot learned 33. On a ship with a marine gas turbine as shown in the illustration, a fire emergency stop is initiated when __________Not learned 34. The two main types of compressor stall are known as what?Not learned 35. In order to get a ready indication for a normal start with a GE LM2500 gas turbine engine, what permissive(s) must be met?Not learned 36. On a gas turbine engine, a high outside air temperature can cause high turbine inlet temperature, low mass/weight of air flow through the turbine, and which of the following conditions?Not learned 37. Assuming that the turbine inlet temperature of a gas turbine engine remains constant, which of the following operating parameter changes would be noted with an increase in the compressor inlet air temperature?Not learned 38. What action should you take if full power vibration limits are exceeded on a gas turbine engine?Not learned 39. Which of the following is the most probable cause for the sump oil to be excessively aerated on an aeroderivative main propulsion gas turbine engine?Not learned 40. Your first step in response to a gas turbine engine high lube oil sump temperature alarm would be which of the following?Not learned 41. Which of the following is the most probable cause if, while underway, the main propulsion gas turbine air intake blow-in doors open?Not learned 42. In which of the following ways can compressor surge cause excessive temperatures in the turbine section?Not learned 43. If a fire is detected in a main propulsion gas turbine enclosure, which of the following would occur prior to automatic release of the fire extinguishing agent?Not learned 44. During an operation of a main propulsion gas turbine, the engine shuts down. Which of the following is the most probable reason for the shutdown?Not learned 45. Which of the following is the most likely cause for the main propulsion gas turbine engine tripping during start up?Not learned 46. Why are loose-fitting blades used on the first several stages of large axial compressors?Not learned 47. What is the disadvantage of a dual-entry centrifugal compressor compared to a single-entry centrifugal compressor?Not learned 48. Each stage of an axial compressor of a gas turbine can compress the atmospheric air a total of how many times?Not learned 49. Compressor tip clang can be usually attributed to which of the following operating conditions?Not learned 50. Compressor rotor blade tip curl is usually caused by which of the following?Not learned 51. Once a compressor is broken in, which of the following factors will most likely cause blade tips to rub?Not learned 52. A centrifugal flow gas turbine uses what type of combustion chamber?Not learned 53. What type of combustor is used by the GE LM2500 gas turbine engine?Not learned 54. During an operation of a gas turbine equipped with an intercooler and recuperator, a low combustion air temperature to the combustor section could be caused by which of the following?Not learned 55. The purpose of the metal spray rub coating on the rotor and stator casing of an axial-type compressor is which of the following?Not learned 56. The turbine nozzle blades convert the combustion gases heat and pressure energy into what form of energy?Not learned 57. How many stages are in the HP turbine of the GE LM2500 gas turbine engine?Not learned 58. The power turbine (PT) of the GE LM2500 gas turbine engine has a total of how many stages?Not learned 59. A gas turbine engine's main lube oil system pump check valve serves to maintain system prime and perform what other function?Not learned 60. How is the lube oil supplied to each bearing in a gas turbine engine controlled?Not learned 61. The lubrication principal utilized by the Kingsbury thrust bearing is which of the following?Not learned 62. What is the primary function of the main fuel control on the GE LM2500 gas turbine engine?Not learned 63. The main fuel control module used on a marine gas turbine engine as shown in the illustration, is responsible for managing which function(s)Not learned 64. On the marine gas turbine shown in the illustration, the gas generator speed sensor is located ______Not learned 65. Lubricating oil contamination in a gas turbine bearing oil sump will most likely come from which of the following?Not learned 66. A fuel analysis report for a gas turbine propelled vessel indicates a calcium level in excess of 0.5 ppm. High calcium levels in distillate fuels for gas turbines can cause which of the following?Not learned 67. A gas turbine engine is experiencing a high rate of corrosion in the hot section of the engine. Which of the following fuel contamination issues could be associated with this problem?Not learned 68. Gear backlash is best described as which of the following?Not learned 69. In cases where both the pinion and gear teeth of the main reduction gear have been slightly indented by foreign material, what action should you take?Not learned 70. When performing a static check to determine tooth contact, you should use which of the following compounds to coat the gear teeth?Not learned 71. The buildup of contamination in a gas turbine will cause all of the following conditions EXCEPT which of the following?Not learned 72. The effectiveness of an off-line water wash of a GE LM2500 gas turbine engine can be enhanced by doing which of the following?Not learned 73. On a gas turbine propulsion vessel, you notice a slow but steady increase in gas turbine vibration and specific fuel consumption as the voyage has progressed. What would be a good maintenance technique to use to correct these increases?Not learned 74. How do you gain access to the burner units of a can-annular combustor to perform maintenance?Not learned 75. What are the two prime sources of deposits that build up on compressor blades?Not learned 76. To manually rotate the GE LM2500 gas turbine engine, you should use which of the following tools?Not learned 77. On a GE LM2500 gas turbine powered vessel you are conducting a borescope inspection of the compressor. What is used on each compressor stage as a reference for indexing the blades?Not learned 78. Zero reference for the GE LM2500 gas turbine engine is established by the use of which of the following engine components?Not learned 79. When conducting a borescope inspection of the compressor, why can airfoil and tip cracks be difficult to detect?Not learned 80. When inspecting the combustion section of a gas turbine engine, what wattage light source should you use?Not learned 81. When dissimilar metals come in contact with a conductor, which of the following types of metal deterioration takes place?Not learned 82. A reddish-colored oxide usually forms on which of the following metals?Not learned 83. A white-gray powdery deposit can usually be found on which of the following metals?Not learned 84. Cadmium and zinc coatings provide which of the following type of protection for the base metal?Not learned 85. You are conducting a borescope inspection of the compressor section of a GE LM2500 gas turbine. In stage four, you see a slight tilt to one blade and the blade platform is raised higher than the other blades. What could be a cause of this condition and what would be your course of action?Not learned 86. A compressor blade platform that is tilted or raised may indicate which of the following failures?Not learned 87. When tip clang takes place on a gas turbine engine, the major damage occurs to what area of the blade?Not learned 88. The dimples of a combustor dome band that has a low operating time will usually have what kind of damage?Not learned 89. Distortion of the combustor liner assembly is evident when you observe which of the following conditions?Not learned 90. When preparing to light off a cold boiler equipped with a return flow fuel oil system, the recirculating valve directs the flow of oil __________.Not learned 91. Casing drains may be required on a waste heat boiler gas passage side to __________.Not learned 92. In general, diesel engine waste heat boiler construction is usually of the _________.Not learned 93. The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust __________.Not learned 94. With which of the following types of diesel engine arrangements is a waste heat boiler most likely to produce the maximum steam pressure, temperature, and flow conditions?Not learned 95. The gauge glass on a coil-type auxiliary boiler is connected to the __________.Not learned 96. Constant capacity, pressure atomizing, fuel burners designed to meet a wide variation in steaming loads on a boiler, are __________.Not learned 97. Why should the main steam stop valve of an auxiliary boiler be eased off its seat and then gently closed before lighting off?Not learned 98. During unsafe firing conditions in a large automatic auxiliary boiler, various control actuators are interlocked with the burner circuit to prevent start-up, in addition to safety shutdown. These controls are referred to as __________.Not learned 99. The pressuretrol which is installed on an auxiliary boiler senses steam pressure changes and __________.Not learned 100. While air is being compressed in a centrifugal flow gas turbine, what happens to the direction of air flow?Not learned 101. For the same amount of available power, how does a low-speed two-stroke diesel engine compare to a recuperated gas turbine configuration?Not learned 102. Assuming you maintain the same power output, how will a decrease in the compressor inlet air temperature effect a gas turbine engine's efficiency and fuel consumption?Not learned 103. An axial compressor basically consists of which of the following?Not learned 104. An axial compressor stator vane that is mechanically adjusted to provide optimum compressor performance over a wide operating range is referred to as which of the following?Not learned 105. The circle of turbine stationary vanes that convert pressure and thermal energy to velocity energy and direct the combustion gases in the direction of turbine wheel rotation is referred to as what?Not learned 106. How is the clutch shown in the attached illustration engagedNot learned 107. In comparing a centrifugal-type to an axial-type compressor, which of the following statements is true?Not learned 108. What is a compressor midspan shroud?Not learned 109. You are conducting a borescope inspection of the combustor section of a GE LM2500 gas turbine engine. You observe a one square inch hole in the combustor dome where burn through has removed the metal. What would be your course of action?Not learned 110. When conducting a borescope inspection, you must be aware of all of the following factors EXCEPT which?Not learned 111. What is the designed compressor pressure ratio of the gas turbine compressor rotor shown in the illustrationNot learned 112. The divergent area of the exhaust duct aids in what process?Not learned 113. Electric igniters used on modern marine gas turbine engines, commonly operate on a secondary voltage of _________Not learned 114. The electrostatic vent fog precipitator removes oil mist from which of the following areas?Not learned 115. Which of the following components are installed in the lube oil system shown in the illustrationNot learned 116. Which of the following conditions will NOT be the result of a build-up of deposits in a gas turbine compressor?Not learned 117. Which of the following designs is the most satisfactory method for attaching turbine blades to the rotor disk?Not learned 118. Which of the following is the main advantage of a split-axial compressor case?Not learned 119. Which of the following statements about the intercooled-recuperated gas turbine cycle is trueNot learned 120. Which of the following statements is true concerning axial compressor disk-type rotors?Not learned 121. Which of the following statements is true regarding centrifugal compressors?Not learned 122. Which of the following is true concerning the main engine lube oil system of the marine gas turbine shown in the illustrationNot learned 123. The fuel oil back pressure regulator on the fuel system shown in the illustration, returns fuel to which of the followingNot learned 124. The fuel purge valve on the marine gas turbine shown in the illustration, is opened _________Not learned 125. In a gas turbine engine, the majority of the energy is added to the working fluid in which of the following components?Not learned 126. On a gas turbine powered vessel, what is the last step after an off-line water wash?Not learned 127. On the gas turbine shown in the illustration, which of the following best describes the main principle of operation of the component contained within the area labeled "C"Not learned 128. For the GE LM2500 gas turbine engine shown in the illustration, the HP turbine 1st stage nozzle vanes are cooled by which of the followingNot learned 129. In the marine gas turbine engine shown in the illustration, the HP turbine 2nd stage nozzle vanes are cooled by which of the followingNot learned 130. Most GTE fuel nozzles have passages for all of the following except ____________.Not learned 131. What type of gas turbine cycle configuration is shown in the illustrationNot learned 132. Why are the high-pressure turbine blades generally of the impulse/reaction type?Not learned 133. HP turbine blades are generally cooled by which of the following methods?Not learned 134. How many fuel igniters would be installed on the marine gas turbine engine shown in the illustrationNot learned 135. How many lube oil sumps are installed on the marine gas turbine engine shown in the illustrationNot learned 136. On the marine gas turbine engine panel shown in the illustration, which of the following conditions would prevent the auto-start sequence from successfully completingNot learned 137. On the marine gas turbine engine shown in the illustration, what temperature should be carefully monitored following a shutdown for an engine fireNot learned 138. On marine gas turbines equipped with fuel oil nozzles as shown in the illustration, the minimum fuel oil manifold pressure for proper operation should be _________Not learned 139. In the operation of a marine propulsion gas turbine, kinetic and thermal energy required to drive the main propeller shaft are extracted by which of the following?Not learned 140. You are preparing for a borescope inspection of a gas turbine engine. Prior to the inspection it is recommended that you do which of the following?Not learned 141. You are preparing for a borescope inspection of an LM2500 gas turbine engine. You are reviewing the correct geometric orientation nomenclature which includes which of the following?Not learned 142. To prevent overheating of the illustrated turbine blade, which of the following fluids is circulated through it via the shaped internal passagesNot learned 143. Provisions for avoiding the buildup of ice on the intake air surfaces of a gas turbine plant can be found where?Not learned 144. The purpose of the air shroud (swirl cup) around the tip of the fuel nozzle of an GE LM2500 gas turbine engine is which of the following?Not learned 145. Why is safety-wiring, or lock wiring of gas turbine parts required?Not learned 146. As shown in the illustration of a gas turbine fuel oil system, when the engine fuel oil valves are de-energized, the remaining fuel left in the system is recirculated back to which of the followingNot learned 147. The six borescope ports located in the compressor rear frame casing of the marine propulsion gas turbine shown, can be used to inspect all EXCEPT which of the following componentsNot learned 148. What is the term used to describe the stationary vanes preceding the first stage of an axial compressor?Not learned 149. The three most common types of combustors used in gas turbine engines are which of the following?Not learned 150. Turbine disks are commonly attached to the shaft by which of the following methods?Not learned 151. The turbine nozzle blades convert the combustion gases heat and pressure energy into what form of energy?Not learned 152. The turbine nozzles convert heat and pressure energy to velocity energy by means of which of the following?Not learned 153. A turbine stage is represented by which of the following components and in which order?Not learned 154. The two basic types of compressors used in gas turbine engines are which of the following?Not learned 155. Two functions of the compressor stator vanes include which of the following?Not learned 156. What are the two principal functions of the turbine nozzle guide vanes?Not learned 157. What type of main lube oil supply and scavenging pump is installed on the marine gas turbine engine shown in the illustrationNot learned 158. What type of metallurgical failure does Item B represent in the illustrationNot learned 159. What type of metallurgical failure does Item A represent in the illustrationNot learned 160. While underway on a ship with gas turbine engines, the most likely indication of an engine stall is which of the following?Not learned 161. Variable stator vanes give an axial gas turbine compressor which of the following capabilities?Not learned 162. A photoelectric cell installed in an automatically fired auxiliary boiler burner management system __________.Not learned 163. For the GE LM2500 gas turbine engine shown in the illustration, the 13th stage bleed air is used for which of the followingNot learned