Trouble-shooting is the step-by-step procedure used to determine the cause for a given problem and then selecting the best and quickest way to solve that problem. While the use of turbochargers and automatic controllers has complicated the trouble-shooting procedures, always start by discussing the problem with the pilot and the facility management. They will assist you in narrowing the problem to as few possibilities as possible. In the case of twin engine aircraft, make sure you are working on the correct engine. After a thorough discussion and verbal analysis of the problem, you are ready to go to work. If you are an experienced mechanic, you may be able to automatically eliminate some of the probable causes. If you are new on the job, you will have to go through all of the probable causes. The important thing to remember is to always start with the simple and inexpensive things first, and then work toward the more complicated, time consuming, and expensive things later.