TY - JOUR N2 - This article investigates unstable tiltrotor in hover system identification from flight test data. The aircraft dynamics was described by a linear model defined in Body-Fixed-Coordinate System. Output Error Method was selected in order to obtain stability and control derivatives in lateral motion. For estimating model parameters both time and frequency domain formulations were applied. To improve the system identification performed in the time domain, a stabilization matrix was included for evaluating the states. In the end, estimates obtained from various Output Error Method formulations were compared in terms of parameters accuracy and time histories. Evaluations were performed in MATLAB R2009b environment. L1 - http://www.journals.pan.pl/Content/104231/PDF/ame-2017-0002.pdf L2 - http://www.journals.pan.pl/Content/104231 PY - 2017 IS - No 1 EP - 36 DO - 10.1515/meceng-2017-0002 KW - flight dynamics KW - system identification KW - output error method KW - maximum likelihood KW - unstable systems KW - tiltrotors A1 - Lichota, Piotr A1 - Szulczyk, Joanna PB - Polish Academy of Sciences, Committee on Machine Building VL - vol. 64 DA - 2017 T1 - Output Error Method for tiltrotor unstable in hover SP - 23 UR - http://www.journals.pan.pl/dlibra/publication/edition/104231 T2 - Archive of Mechanical Engineering ER -