Abstract: The modeling and parameter estimation of the DORNIERDO 28 research aircraft is a part of the special research program 212of West Germany "airtraffic safety" (SFB 212“Sicherheit im Luftve-rkehr").In this paper a nonlinear multi-point mathematical model withsix-degree-of-freedom for DO 28 parameter estimation is presented. Themodel considers not only the high nonlinearity of aircraft motions, thecharacteristics of the propller of the wings and of the horizontal stabi-liter, but also the wind disturbance by reconstruction of a quasi-station-ary windfield, the improved algorithm for thrust calculation and thenecessary corrections of the measured input/output signals through fli-ght-test-data-compatibility-check. Nonlinear Maximum-Likelihood me-thod and modified Newton一Raphson optimization algorithm are appliedto the estimation of the stability and control derivatives of the DO 28aircraft. Compared with one-point model of aircraft motion it is shownthat Mululti一point model can moreand is more suitable for aircraftaccurately describe the aircraft motionparameter estimation.

Key words: mum-Likeiihood modeling, multi一point model estimation, quasi stationary of aircraft motion, windfield, flight test data.