What FAR 91.313 Actually Covers
FAR 91.313 governs the operating limitations for experimental category aircraft. Unlike certificated aircraft operating under a standard, restricted, or limited airworthiness certificate, experimental aircraft carry unique restrictions that reflect the nature of their certification — they haven't completed the full type certification process and exist outside the normal airworthiness framework.
The regulation applies broadly: amateur-built aircraft, research and development platforms, exhibition aircraft, air racing competitors, crew training aircraft, and market survey operations all fall under the experimental category umbrella. Each has its own set of authorized purposes, and operating outside those purposes is a violation regardless of how airworthy the aircraft actually is.
The Core Limitations
91.313 imposes several hard restrictions that pilots need to understand before logging experimental time or discussing the regulation in an interview context:
- No carrying persons or property for compensation or hire. This is absolute. Unlike Part 135 or Part 91 subpart K operations with certificated aircraft, experimental aircraft cannot be used for commercial carriage under any interpretation.
- Flight over densely populated areas is prohibited unless the FAA has issued specific authorization. This includes congested airways. The pilot in command bears responsibility for routing that avoids these areas.
- Flight over populated areas during takeoff and landing must be avoided to the maximum extent possible. This is operationally significant at airports surrounded by residential development.
- Operating limitations document governs everything else. The aircraft's specific operating limitations, issued as part of the experimental airworthiness certificate, set the envelope — airspeed, altitude, geographic restrictions, and authorized flight crew. These limitations vary by aircraft and purpose category.
An amateur-built RV-8 operating under an experimental/amateur-built certificate may have a geographic restriction limiting flight to within a certain radius during the Phase I flight testing period (typically 25–50 hours). Once Phase I is complete and the builder has expanded the operating area, the aircraft can operate more broadly — but the commercial carriage prohibition and populated area restrictions remain in effect permanently.
Phase I vs. Phase II Operations
For amateur-built and some other experimental aircraft, the FAA establishes a two-phase structure within the operating limitations:
Phase I — Flight Testing
The initial airworthiness phase. The FAA assigns a geographic test area, typically centered on the home airport, and requires the builder or a qualified pilot to accomplish a defined number of flight hours to establish airworthiness. Passengers are generally prohibited during Phase I, and the aircraft must stay within the designated area except in emergencies.
Phase II — Normal Operations
Once Phase I requirements are met and the operating limitations are amended, the aircraft can operate more broadly. Passengers are permitted. However, 91.313 restrictions — particularly the commercial carriage prohibition and populated area requirements — remain fully in force. There is no Phase II equivalent of a standard airworthiness certificate.
Why This Comes Up in Airline Interviews
Examiners at regional and major carriers occasionally probe experimental aircraft knowledge for two reasons: to verify regulatory depth, and to identify pilots who have logged significant time in experimental aircraft without understanding the limitations under which that time was flown.
If you've built hours in an experimental aircraft, be prepared to articulate the specific operating limitations applicable to that aircraft and how you ensured compliance. Vague answers about "it's basically like a normal airplane" are red flags to a technical interviewer.
For pilots preparing for technical rounds at carriers like United or Delta, regulatory knowledge questions often appear alongside systems and aerodynamics questions. Knowing where 91.313 sits relative to 91.319 (which covers aircraft having experimental certificates) and how the experimental category interacts with pilot certification requirements demonstrates the kind of layered regulatory literacy these carriers expect.
If you want to stress-test your regulatory knowledge before your next interview, the Vectors to Hired AI Voice Coach scores your spoken answers on a 1–5 scale using the same criteria a real interviewer would apply — including specificity, accuracy, and conciseness. The platform's question bank pulls from actual recent interview gouge across 55 operators, so you're drilling the questions that are actually being asked right now, not five-year-old prep material.
For a broader look at how airworthiness certification categories interact with pilot operating privileges, see the Airworthiness Certificate Categories guide.
The Bottom Line
FAR 91.313 is not a complex regulation, but it's one where imprecision has real consequences — both operationally and in how you're perceived in a technical interview. Know the commercial carriage prohibition cold. Understand the populated area restrictions. Know the difference between the operating limitations document and the regulation itself. And if you've flown experimental aircraft, be ready to explain exactly how you operated within those constraints.