This paper presents a design of parameter estimator for a Micro Air Vehicle (MAV) named Sarika-1. Estimator is needed in applications where all parameters cannot be measured directly due to various reasons. In this work, suitable linear Kalman filter estimator is designed for the longitudinal and lateral dynamics of Sarika-1.The Linear Discrete Kalman filter is designed to estimate its longitudinal state variables viz. angle of attack, forward velocity, pitch rate and pitch angle and the lateral state variables viz. Side slip angle, roll rate, yaw rate, and bank angle. Filter is designed in MATLAB and is verified using its offline simulation. For the simulation, the measurement data of pitch rate and normal acceleration collected at the time of real flight are used for longitudinal dynamics and lateral acceleration, roll rate and yaw rate collected at the time of real flight are used for lateral dynamics. It is found that the estimated values of the state variables matches well with the corresponding actual values.