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Written by Rich Hanson
How high can I fly?
As seen in the April 2017 issue of
Model Aviation.

This is a question that repeatedly comes up and is somewhat clouded in the seemingly conflicting and ambiguous information provided in many of the guidance and policy statements published by the FAA. However, it was made clear in a letter signed by the director of the Unmanned Aircraft Systems Integration Office, Earl Lawrence, on July 7, 2016, that in accordance with the Special Rule for Model Aircraft (Section 336), established by Congress as part of the FAA Modernization and Reform Act of 2012, “Model aircraft may be flown consistently with Section 336 and agency (FAA) guidance at altitudes above 400 feet when following a community-based organization’s safety guidelines.”

Perhaps a more appropriate question is: How high should I fly my model aircraft? In general, the short answer is, no higher than is necessary to maintain the safe and unobtrusive operation of your model aircraft, keeping in mind that to do so might mean operating above 400 feet for short periods of time. Some aeromodeling disciplines, such as thermal soaring, operate routinely above 400 feet because of the nature of the activity.

Why 400 feet? The 400 feet above ground level (AGL) criterion has long been a benchmark safety guideline to separate traditional model aircraft, and now unmanned aircraft systems (UAS), from most of the manned aircraft traffic in the national airspace. Operating model aircraft below 400 feet provides a 100-foot safety buffer from manned aircraft that are typically required to fly 500 feet or higher above obstacles on the ground.

Of course, there are still some manned aircraft operations that occur below 500 feet, such as helicopters, ultralights, and agricultural applicators (crop dusters), and all manned aircraft necessarily operate below 500 feet when they’re taking off and landing at airports. As such, model aircraft are always required to remain well clear of manned aircraft operations.

Some believe that the 400-foot guideline was established because of the new multirotor (drone) phenomena. Actually, that’s not the case. The 400-foot guideline has been around for more than 40 years. This safety standard was first established by FAA’s Air Traffic Services in 1972 and was published that year in the November issue of American Aircraft Modeler. It was again formalized in an advisory circular (AC 91-57) published in June 1981, and revised again in 2015 as AC 91-57A.

In keeping with the basic philosophy that modelers should not fly higher than is necessary to maintain the safe and unobtrusive operation of their model aircraft, AMA supports the 400-foot guideline as a general safety principle.

In answering the question, how high can I fly, AMA members should refer to the Special Rule for Model Aircraft, the AMA Safety Code, and AMA’s related safety documents.

Section 336 requires that model aircraft be “flown within visual line of sight of the person operating the aircraft.” This is both a horizontal and vertical limitation. Modelers must be able to see their aircraft, know its orientation and be able to manually control (radio control) the aircraft at all times in order to safely terminate the flight. The law also requires that the aircraft be “operated in a manner that does not interfere with and gives way to any manned aircraft.”

AMA’s Safety Code requires model aircraft to remain below 400 feet AGL when within 3 miles of an airport unless previous arrangements have been made with the airport to allow for safe operations above 400 feet. The AMA Safety Code also requires that modelers not interfere with, and remain well clear of, manned aircraft and to “See and Avoid” all aircraft and obstacles in accordance with AMA Document 540-D.

The bottom line is that we share the airspace with myriad aircraft and operators, and as part of the aviation community, we must continue to operate our aircraft in a safe, responsible, and community-friendly manner.

-Rich Hanson


My foamies start to look like dots at 200' AGL, so I think I'm within the Safety Code.

There is the issue of controlled airspace that affects how high you might fly in any particular area and should have been addressed in this article. The heights of 400 ft and 500 ft are not arbitrary selections, they are based on how the airspace is divided up for air traffic control.

Intruding into controlled airspace can create a navigation hazard for manned aircraft and you would NOT have the 336 model aircraft carve out for defense if the FAA comes down on you for violating that airspace (and they're fully within their mandate to do just that, BTW)!

It might also be a good topic for separate article, but it's important enough that needs to be discussed!


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