For a UAS operated recreationally, may altitude exceed 400 AGL? AMA rules state in several places that flight above 400 AGL should be avoided. And close to airports there is a more firmly worded restriction. But away from an airport, and presumably in Class G, what are the altitude restrictions?

This question presumes 14 CFR 101 applies.

Addendum to question: FAA appears to be attempting to impose a 400AGL restriction on 101 operations, without regulation. See the amended AC: https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_91-57A_Ch_1.pdf, stating: Model aircraft operators should follow best practices including limiting operations to 400 feet above ground level (AGL).

  • $\begingroup$ This question is now obsolete due to changing regulations. If you are still interested in the answer, you could re-ask, modifying the phrasing to say "under all currently applicable regulations" or "under all regulations in effect as of March 1 2020", etc. Or if you are ONLY Interested in the effect of 14 CFR 101 on the answer, not other regulations, you could re-ask in a way that makes that clear. $\endgroup$ Feb 24, 2020 at 17:45

3 Answers 3


There's no specific altitude restriction for model aircraft anywhere in part 101 (that I can see). Even within 5 miles of an airport you only have to inform the tower, per 101.41(e):

When flown within 5 miles of an airport, the operator of the aircraft provides the airport operator and the airport air traffic control tower (when an air traffic facility is located at the airport) with prior notice of the operation.

However, practically speaking there is an indirect altitude restriction in 101.1:

For purposes of this part, a model aircraft is an unmanned aircraft that is:


(ii) Flown within visual line of sight of the person operating the aircraft

In other words, you have to be able to see the model aircraft and that limits the altitude and distance you can fly it at. It's also worth noting that 101.43 is very broadly written:

§101.43 Endangering the safety of the National Airspace System.

No person may operate model aircraft so as to endanger the safety of the national airspace system.

Arguably, that also implies you shouldn't fly any higher than you really need to.

  • $\begingroup$ I tend to agree with you. However, I am not really sure what you mean by "any higher than you really need to" because there can be reasons for flying higher. For example, a bigger view. I get nervous with the concept of 700 ft drones, though. As it is I am nervous with instrument approaches, especially non-precision approaches where the time spent at a lower altitude might be longer. $\endgroup$
    – mongo
    Oct 10, 2017 at 16:03
  • $\begingroup$ @mongo I agree, I just meant that the higher you go the more important it is to have a good reason (IMO). $\endgroup$
    – Pondlife
    Oct 10, 2017 at 16:14
  • $\begingroup$ One issue is the interpretation of when one endangers NAS. I haven't found many NTSB cases on that. $\endgroup$
    – mongo
    Oct 10, 2017 at 16:44
  • 1
    $\begingroup$ @mongo, I would be willing to bet that 101.43 is intentionally vague so that if there are any issues, they've got a catch-all regulation to get you with. $\endgroup$
    – FreeMan
    Oct 10, 2017 at 20:18
  • $\begingroup$ Well, I have a meeting with the FSDO to discuss this and some related things first thing in the morning. $\endgroup$
    – mongo
    Oct 10, 2017 at 23:41

There are no specific altitude restrictions.

The reason for the 400 foot guidance is that powered aircraft are supposed to stay at least 500 feet above the ground or any structure on the ground. So, if you stay under 400 feet then you minimize chance of collision with a full-size aircraft.

The main exceptions would be crop dusters and flight paths into landing zones, such as airports, heliports, helipads and sea plane bases where aircraft will descend below 500 feet above the ground objects.

  • $\begingroup$ Helicopters have no such 500 foot rule. Worse is that helicopters are the ones usually flying low. See 91.119 ecfr.gov/cgi-bin/… $\endgroup$
    – Steve Kuo
    Oct 10, 2017 at 21:54
  • $\begingroup$ @Tyler Durden, Do you have an authority how the 400 foot was initially derived? $\endgroup$
    – mongo
    Oct 11, 2017 at 1:20

While FAR 101 is intended as advisory or "best practice", to get the complete picture you must go beyond FAR 101. FAR 107 places a strict altitude restriction and/or proximity of 400ft to taller structures. Unless operating under other provision such as "commercial operator" this is a mandatory restriction.

FAA FAR 107 states, "The maximum allowable altitude is 400 feet above the ground, and higher if your drone remains within 400 feet of a structure."


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