Autonomous systems have become an important fixture in modern day life. Certification of ethical decision-making in autonomous system is necessary to minimize harm. In this work, a formalism of ethical decision making under uncertainty is described. The ethical principles are incorporated using Deontic logic rules of obligations, forbidden actions, and permissible actions. The uncertainty in the environment is modeled using interval discrete-time Markov chain. A tractable probabilistic model checking on interval discrete time Markov chain model is constructed for evaluation ethical decision making in a system. The results from experiments are performed using probabilistic model checking on a tractable model of interval discrete time Markov chain and statistical inference is conducted on a prototype of a moving aircraft is presented.