In this paper, the authors study the problem of modeling packet dropout for Unmanned Aerial Vehicle (UAV) wireless communications. A Markov model is proposed, which incorporates the effects of Ricean fading. Unlike the classic Markov channel models, the proposed model is a two-state hidden Markov model with each state being associated with a time-varying packet error rate. The model is able to capture the non-stationary packet dropout characteristics of wireless channels. Intuitively, they use the time-varying packet error rate associated with the channels to describe the non-stationary nature of the packet dropouts, and the two-state Markov model to capture the correlation of the packet dropouts.