Abstract：The assembly coordination accuracy of aircraft manufacturing becomes more and more strict with the
development of the aircraft structure and process. So defining fairly aircraft components dimension to achieve process optimum
through tolerance analysis is an inevitable trend. This thesis introduces and researches the basic theory, with applying
selection of certain aircraft components datum. Defining datum is decided by function request, indicating transfer deviation
by datum and datum consistency principia of aircraft components. The datum selection method can be applied to dimension
design. Assembly quality is improved by defining fairly aircraft components datum, with reducing production cost and increasing
productivity in some case.
2016, 
