The scheduled and on-demand air services with Title 14 Code of Federal Regulations (CFR) Part 135 certificate are operating with relatively less stringent safety program criteria compared to Part 121 operations. The Part 135 aircraft flight operation was identified as one of the most wanted transportation safety improvements by the National Transportation Safety Board (NTSB). Implementation of flight data monitoring (FDM) programs was recommended to mitigate the risk of Part 135 operations. The FDM program is the process of routinely collecting and analyzing aircraft operational data to provide insight into flight operations for safety improvement. The development of more practical and effective FDM programs for Part 135 operations depends on the identification of critical part of flight parameters. This study, focusing on the aircraft issue-related accidents in Part 135 aircraft operations recorded in the NTSB aircraft accident database, analyzed the common aircraft issues that caused aircraft accidents and the risk factors that are potentially associated with aircraft issue caused accidents in Part 135 operations. General descriptive analysis and Chi-square linear-by-linear association were adopted to provide insights into statistical characteristics of aircraft issue caused accidents, logistic regression was employed to explore the risk factors associated with such type of accidents. This study identified a list of common aircraft issues in Part 135 operations and risk factors that might contribute to aircraft issue caused mishaps. The findings are expected to facilitate better development and implementation of FDM programs for Part 135 operations by identifying critical aircraft issues and risk factors that should be monitored with more caution. Recommendations were proposed based upon the findings.