Reliability of aircraft varies with different missions, because load conditions are always diverse. In limited sample size circumstances, convention aircraft mission reliability assessment method can only give an average result for a kind of mission. Motivated by the practical need of reliability assessment for an individual mission, this paper constructs a novel method, which can assess reliability for a specific mission based on flight parameters. The mission reliability model can be established according to the relationship between flight loads, flight parameters, and reliability via adopting fault data and flight parameters synthetically. Statistical inference of aircraft failure rate is proposed, and then, the mission reliability can be assessed according to the fault data of the focused aircraft. It is worth noticing that the proposed method can also assess the reliability for a mission category via conducting an average calculation across all individual missions belonging to the target mission category. An illustrative example shows that the proposed method not only can give reliability assessments with a same precision with existing approaches for a specific mission category but also can reasonably assess the reliability regarding an individual mission.