Engine vibrations are among the most important parameters used to evaluate engine operating service limits. Several case studies showed that these vibration levels could be affected by the malfunction of the internal acceleration sensors, causing a false positive error. If vibration levels overcome the ones described by the Original Equipment Manufacturer (OEM) the engine must be dismounted from the aircraft, causing delays in the normal operating modes of the airline company. Lufthansa Technik AG (LHT) is interested in solving the problem. One of the first approaches is to use an external sensor to validate the information obtained from the internal ones.