Final answer:
Blade conditions that can cause engine vibration include damage like nicks and cracks, imbalance due to wear, foreign object damage, deposits, improper installation, and manufacturing defects.
Step-by-step explanation:
Engine vibration can be caused by a variety of blade conditions in aircraft engines or other types of engines that use rotating blades. Some possible conditions include blade damage, such as nicks, cracks, or bends, which can disturb the balance of the engine. Imbalance due to uneven wear or erosion of the blades can also lead to vibration. Foreign objects that strike the blades or deposits that build up unevenly can affect the aerodynamics of the blades and result in vibration. In addition, if blades are not installed correctly or if there are manufacturing defects, these can also lead to engine vibration.