Question: What size and location of flight test area can I have?
Answer: Obviously everyone wants the largest area they can get. Ive even been asked: Can I get a corridor from my home airport to Oshkosh, Wisconsin? The answer to that is probably going to be, No!
Although the FAA guideline is a 25-n.m. radius from the home airport, that is not always practical with todays modern amateur-built aircraft. For example, a Glasair III with a 25-n.m. radius would have the pilot constantly flying in circles. On the other hand, such a radius is perfectly suitable for a Light Sport/ultralight aircraft where the cruise speed is about 75 mph. So the test area must be suited to the type of aircraft. The FAA has given DARs some latitude in this area as long as we use common sense.
Another point: The test area does not have to be centered on the home airport. For example, if your home airport is at the edge of Class B airspace, you may pick a point farther away from that airspace as long as your home airport is still within the designated area. Remember, you are not allowed inside Class A or B airspace during Phase I of your flight testing. Every DAR will have personal standards for a certain speed of aircraft. If you wish a deviation from these standards, you must coordinate with the DAR before the inspection. For example, with the RV series of aircraft, I typically give a 75-n.m. radius from the home airport plus a couple of airports outside this area. Airports outside the normal radius are sometimes requested for a paint shop or transponder certification that may not be available within the assigned area. These airports must still be within a reasonable distance, and you will only be allowed a straight-line corridor to them.
One critical factor is that the test area may not be over densely populated areas, and you must be able to make a safe emergency landing in the event of a power failure without hazard to persons or property. If the aircraft is located at an airport that does not have an entry/exit route that avoids densely populated areas, the DAR must deny the application until the aircraft is moved to another more suitable airport.
Occasionally I get a request for a two-part Phase I where the applicant wants to relocate the aircraft during this phase. Maybe he built his aircraft at a builders assistance center and wants to take the aircraft to his home base. While this is a possibility, it is rare, and the reason and practicality of the request must be thoroughly discussed beforehand. Also, if this involves changing to the jurisdiction of another FSDO, all FSDOs involved must approve of the plan.
Please send your questions for DAR Asberry to firstname.lastname@example.org with Ask the DAR in the subject line.