At this altitude, most drones cannot generate enough lift to allow their own weight to lift off the ground. Although air pressure decreases with an increase in altitude, the reduction in lift only makes it impossible for drones to fly at an altitude of around 13,000 feet. In terms of physical capability, there’s nothing that can stop drones from flying above 400 feet. Is it physically possible for drones to fly above 400 feet? Any manned aircraft flying in the vicinity will similarly adjust their cruising altitudes, so there shouldn’t be any risk of close encounters as long you stay within the 400-foot limit. The 400-foot limit is measured above the surface. This is in contrast to measuring it from an absolute reference point, or from sea level. What the rule implies is that the 400-foot limit is measured “above ground level.”. For instance, an airplane cruising at 500 feet will gain altitude as it passes a large building, communication tower, or a mountain. The working of this exception is that manned aircraft will also adjust their cruising altitude when they pass over any large structures.

From what reference point should 400 feet be measured from?Īccording to Section 107.51, drones can fly above 400 feet if they are flying within the vicinity of a structure. When flying 400 feet over an obstacle in uncontrolled airspace, you also have to stay out of controlled airspace that requires authorization, such as class B, C, or D.įor example, if you are trying to inspect a structure that is 1500 feet tall, but a layer of Class B airspace starts at 1200 feet AGL, you can only fly near this structure up to to 1199 feet AGL. This means that when in Class B, C, D, or E2, you cannot fly 400 feet over structures. This statement essentially prevents you from flying any higher than the altitude you were approved for, regardless of the presence of structures. Case in point, when you receive a LAANC authorization, the following statement is accompanied with your authorization:Īltitude limits are absolute values above ground level which shall not be added to the height of any structures. Flying over structures in controlled airspaceĪ common misconception about the regulation in 107.51 is that you can apply it in any airspace. Drone crashes are one thing, but when they endanger manned aircraft, they run the risk of causing much more severe damage and loss of life. Of these cases, there were 28 instances where the manned aircraft had to execute evasive maneuvers to avoid getting into proximity danger with the drones. To further emphasize the importance of this altitude limit, statistics showed that there were 921 recorded incidents of close encounters between drones and manned aircraft before the Part 107 rules were implemented. This was a decision that most of the drone community agreed with. The 100-foot buffer was established to avoid any close encounters between drones and manned aircraft. The original notice of proposed rulemaking (NPRM) for Part 107 set the maximum altitude for drones at 500 feet, but the final published rule reduced this limit to 400 feet. Most manned aircraft activities occur at 500 feet or above, except within the controlled airspace near airports. The basis for the 400-foot limit is easy to explain.

What exactly is the FAA trying to avoid when it imposed the 400-foot limit? What’s the basis for the 400-foot limit? To be able to dissect the specifics of the rule, it would be a good idea to understand the rationale behind it. There’s still a bit of ambiguity, though, as Part 107 does not provide a definition of a ‘structure’ or precisely from what reference point the 400-foot limit should be measured from. The way that the rule is stated immediately offers an exception: that it’s possible to fly above 400 feet if you are flying in the vicinity of a (presumably) large structure. “The altitude of the small unmanned aircraft cannot be higher than 400 feet above ground level unless the small unmanned aircraft is (1) flown within a 400-foot radius of a structure, and (2) does not fly higher than 400 feet above the structure’s immediate uppermost limit.” Pertaining to altitude, item B of the Section states that: This section is entitled “Operating limitations for small unmanned aircraft” and contains a set of limits associated with speed, altitude, and visibility. The relevant rules under Part 107 are summarized within Section 107.51. To make sure that we are operating within legal boundaries, it would be safer to set the Part 107 rules as the standard. Although 14 CFR Part 107 only applies for drone pilots, it is also the strictest standards created for drone flight. For the best reference to what the law says specifically, we’ll go the definitive aeronautical laws that were created for drone flight – the Part 107 rules.

Fader drone