The National Business Aviation Association has issued a recommendation urging Part 135 operators to conduct a thorough review of any aircraft interior exemptions currently held under their operating certificates. Such exemptions, which may have been granted by the FAA for specific aircraft configurations, cabin materials, emergency equipment installations, or seating arrangements that deviate from standard regulatory requirements, carry defined conditions and expiration parameters that operators must actively track. NBAA's advisory serves as a reminder that these exemptions are not permanent authorizations and that changes in aircraft configuration, operational use, or ownership can affect their continued validity.
For Part 135 charter and air taxi operators, interior exemptions frequently arise in the context of aircraft that were certificated under earlier standards or modified with custom cabin installations not fully compliant with current FAR Part 25 or Part 135 airworthiness requirements. Common exemption areas include seat track configurations, interior material flammability standards, emergency exit accessibility, and passenger safety briefing card requirements. When aircraft undergo refurbishment or when operators acquire used aircraft from other operators or Part 91 owners, the exemption history may not transfer cleanly, and a new operating environment may invalidate conditions under which the original exemption was granted. NBAA's guidance signals that operators should not assume continuity without verification.
The practical compliance burden falls heavily on Directors of Operations and Chief Pilots who are responsible for ensuring that the operating certificate remains in good standing with the FAA. A lapsed or improperly maintained exemption can expose an operator to certificate action, civil penalties, or grounding of specific aircraft during ramp inspections or certificate management reviews. NBAA's recommendation implies that some operators may be carrying exemptions on aircraft where the underlying conditions have shifted—whether through interior modifications, changes in passenger capacity authorizations, or updated FAA policy interpretations—making a proactive audit essential before the FAA identifies a discrepancy.
This advisory reflects a broader regulatory trend toward tighter oversight of Part 135 operations, particularly as the FAA has increased its focus on on-demand charter safety following high-profile accidents and Inspector General reports highlighting inconsistencies in certificate management. The FAA's Flight Standards district offices have demonstrated increased scrutiny of aircraft records during surveillance activities, and interior compliance has emerged as a discrete area of examination alongside pilot training records and maintenance documentation. Operators who have not recently cross-referenced their exemption letters against current aircraft configurations are at measurable compliance risk.
For business aviation broadly, the NBAA recommendation underscores the complexity of managing a mixed fleet under Part 135, where aircraft sourced from various prior operators, manufacturers, and modification centers may carry different regulatory histories. Operators adding aircraft to their certificates through management agreements or dry-lease arrangements should treat interior exemption review as a standard pre-addition checklist item, equivalent to verifying airworthiness directives compliance or training currency. Engaging aviation legal counsel or a qualified aviation consultant to audit exemption documentation is a prudent step, particularly for operators expanding their fleets or those who have not conducted a comprehensive regulatory review in the past 12 to 24 months.