This paper serves as the next chapter in a series of papers on system identification (system ID) for small low-cost unmanned aerial vehicles (UAVs). The purpose of this paper is to answer the question of, what is the next step in the process of system ID once a method of system ID and a model type have been selected? The focus of this paper is to show how sensors, data quality, and data consistency and reconstruction techniques provide an answer to this question. The paper also provides a broader scope for utilizing data consistency and reconstruction in small low-cost UAVs and how it can increase mission assurance and fault tolerance. A brief survey of small low-cost Micro-Electro-Mechanical systems (MEMS) sensors used in UAVs is given. Included in the survey is the data types provided by each sensor and issues of each sensor from a system ID perspective. The process of determining and improving data quality, utilizing data consistency checking and reconstruction techniques is outlined. The paper concludes with guidelines and lessons learned about sensor data for system ID and a future research direction.