Annotation: In the article is considered the influence of Unmanned Air Vehicle's onboard equipment (its dependability) upon the overall performance of the whole complex. The method formulated for determining periods between the checks of technical state of Unmanned Air Vehicle of the onboard equipment. The algorithms are improved for evaluating statistical consequences of Unmanned Air Vehicle technical state during its operation. The drift influence of the measurement parameters and the control unit at time of technical state inspection for Unmanned Air Vehicle onboard equipment was showing. Suggestions for using of the proposed method were offered.