Flying low is a mixed blessing: Sometimes necessary, always demanding, occasionally challenging of your better judgment, low flying comes with special rules and a built-in expectation that your training will instill plenty of respect for potential hazards.
Let’s start with the rules.
FAR 91.119 mostly forbids operating an aircraft “over any congested area of a city, town, or settlement, or over any open air assembly of persons,” below “1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.”
Importantly, anywhere you fly you must operate at “an altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.”
The regulation contains the commonsense exception that these provisions (and a few for helicopters, powered parachutes, and weight-shift-control aircraft) apply “except when necessary for takeoff or landing.”
On any low-altitude flight segment, build in comfortable margin above terrain and obstruction elevations shown on sectional charts, noting that some published figures are approximate. Some airports have mandatory procedures for avoiding noise-sensitive residential areas. General aviation prides itself on its good-neighbor character, so follow those rules carefully.
One instance in which low-altitude flight is not optional is when practicing private pilot ground-reference maneuvers. They should be flown “600 to 1,000 feet above ground level,” so be sure to pick ground references located within a short glide of an unobstructed emergency landing spot like a large open field or a straight stretch of (preferably little-used) roadway. Keep the wind’s speed and direction in mind, and have your emergency landing approach thought out ahead of time.
Once you have earned your pilot certificate and are out flying for fun, a photo opportunity or a view of some scenic place or object may tempt you to duck down—or someone may try to tempt you into a bad decision.
Remember your obligation to practice sound risk management—and keep in mind that even if there is no specific prohibition against the proposed low-altitude foray, it may subject the pilot to action under a regulation that prohibits “careless or reckless operation” for your protection and for the safety of others.