1. A system for synchronized display of panoramic images and visualizations of three-dimensional models for use in assembly of aircraft, comprising: a non-transitory tangible computer-readable storage medium storing panoramic photograph datasets representing panoramic images for a plurality of reference aircraft and three-dimensional model datasets which can be rendered to visualize three-dimensional models for a plurality of current production aircraft that each include design modifications not incorporated in at least one of the plurality of reference aircraft; a display system comprising a multiplicity of pixels; a user interface for converting inputs by a user into electrical signals representing selection inputs; a panoramic image viewer application comprising a panoramic image display process, a viewpoint representation conversion process and a client request process; and a three-dimensional model visualization application comprising a three-dimensional model visualization process and a server response process, wherein: the panoramic image display process is configured to retrieve a panoramic photograph dataset representing a panoramic image of a particular reference aircraft from the non-transitory tangible computer-readable storage medium in response to a panoramic image selection input received from the user interface and then control the display system to display a portion of the panoramic image with a user-selected viewpoint in a first window in response to a viewpoint selection input received from the user interface; the viewpoint representation conversion process is configured to convert an internal representation of the user-selected viewpoint to a viewpoint representation having a format acceptable to the three-dimensional model visualization process; the three-dimensional model visualization process is configured to retrieve a three-dimensional model dataset corresponding to a particular current production aircraft from the non-transitory tangible computer-readable storage medium in response to a three-dimensional model selection input received from the user interface; the client request process is configured to construct and transmit a command data string containing encoded data specifying parameter values of the viewpoint representation formatted for three-dimensional model visualization; the server response process is configured to receive and decode the command data string into specified parameter values of a viewpoint for three-dimensional model visualization; and the three-dimensional model visualization process is further configured to control the display system to display a portion of a three-dimensional model visualization represented by the retrieved three-dimensional model dataset in a second window with the viewpoint specified in the command data string in response to receipt of the specified parameter values from the server response process.