The least squares method has been applied to estimate parameters inan aerodynamic model of a simulated aircraft, using data that can beexpected to available from sensors on an Unmanned Aerial Vehicle. Acombination of two non-linear state observers have been implemented toestimate wind data such as angle of attack, sideslip and dynamic pressure.Simulations have confirmed that the observers are able to estimete thewind data using noisy sensor measurements. Parameter estimation havebeen demonstrated with both measured and estimated wind data.