The paper describes one of the first outcomes of an Italian national research Project on inertial positioning in photogrammetry. The focus of the paper is on the quality which is attainable from direct photogrammetry in an industrial production context. Even if GPS/IMU-aided photogrammetry is used rather widely, it is still useful to perform rigorous quality assessment of this method, because large and diverse case studies are necessary to prove and quantify the capability of a new methodology. Besides, it is necessary to evaluate such methodology in the ordinary operational conditions, rather than considering data acquired in a dedicated, special context. To fulfil these requirements several different flights were considered, which were acquired by an Italian photogrammetric company before the beginning of the Project, purely for production aims, and rigorous quantification of residual parallaxes and accuracy was performed. The origin of the considered data, which is not research-oriented, and the vast and heterogeneous case study – different cities, different flights, different calibrations- make the described test very significant and reliable.