The short answer
HSI’s current AVIRT course overview lists a student-to-instructor ratio of 15:1 and a student-to-equipment ratio of 1:1. That means a private group larger than 15 may require additional authorized instructors, separate sections, or another approved arrangement; it does not necessarily mean the organization can train only 15 people total.
What to know
Arrow’s public page does not state its own minimum or maximum enrollment. Venue size, instructor availability, hands-on stations, online prerequisites, accessibility, scenario safety, and equipment can further limit a session. A lecture-sized room is not automatically suitable for skills practice or movement. Schools and other sensitive environments may also require a different delivery design.
When requesting a quote, give Arrow the expected and maximum attendance and ask for the number of instructors, equipment sets, room dimensions, schedule, observer policy, completion standard, and plan for no-shows or added attendees. Do not exceed the authorized program ratio to reduce price; participants need supervised practice and feedback. If multiple sections are used, ensure each receives the same curriculum and sufficient time. Arrow should publish a maximum only after confirming current HSI standards and its operational capacity.