Section 107.25 prohibits operating a small unmanned aircraft system from a moving aircraft. From a moving land or water-borne vehicle, the operation is allowed only when the small unmanned aircraft is flown over a sparsely populated area and is not transporting another person's property for compensation or hire. A flight that meets those conditions still has to meet the 87-knot groundspeed limit, the rules on flight over people, and the aircraft's own performance limits.
The two sentences in §107.25
Paragraph (a) is the aircraft case: no operations from a moving aircraft. Paragraph (b) is the land or water vehicle case, and it has two conditions that both have to be true. The aircraft is flown over a sparsely populated area, and it is not transporting another person's property for compensation or hire. A moving car over a town, or a moving car hauling someone else's property for pay, is outside that sentence even before any other rule is considered.
Section 107.205(a) puts §107.25 on the list of regulations that can be waived. The same paragraph says no waiver of this provision will be issued to allow the carriage of property of another by aircraft for compensation or hire. Which rules can be waived, and which cannot, is covered on the rules subject to waiver page. The application path itself is on waivers and authorizations.
Operating from a moving vehicle is not the same rule as flying over people who are inside moving vehicles. That second problem is §107.145, explained on the operations over moving vehicles page. Section 107.25 asks where the person at the controls is sitting. Section 107.145 asks what the aircraft is flying over.
Groundspeed still applies
A crew legally operates from a moving truck over a sparsely populated area, which §107.25 can allow. The drone then paces the truck at 92 knots groundspeed. The operation is illegal because §107.51(a) still limits groundspeed to 87 knots (100 miles per hour). Permission to operate from the vehicle does not cancel the speed limit. The limit does not disappear because the control station is moving.
A truck at a modest road speed, with the aircraft holding a slower groundspeed over an empty field beside that road, can satisfy both sections. The 92-knot pace cannot. The speed rule, including the trap of watching airspeed while the groundspeed is the number that counts, is on the maximum groundspeed page. The pilot in the truck also still has to see the aircraft under §107.31, which is the visual line of sight requirement.
A moving boat and a crowded marina
A remote pilot launches from a moving boat and flies over a crowded marina. Section 107.25(b) allows the moving water vehicle only when the aircraft is flown over a sparsely populated area, and only when it is not transporting another person's property for compensation or hire. A crowded marina is not a sparsely populated area. Staying below 100 feet does not create an exception in the section, and launching from a boat does not turn the aircraft into a Category 4 operation.
People on the surface are a second rule. Section 107.39 and Subpart D still decide whether the aircraft may be over human beings. The two sections answer different questions. Clearing §107.25, if the area really is sparse, does not by itself authorize flight over the people on the docks.
The manufacturer's wind limit is still a limit
One assigned item is not a moving-vehicle citation, and it should be answered as written. The manufacturer lists a maximum wind resistance of 22 mph, and the wind is gusting to 24 mph. Treat the flight as a no-go. The published maximum is a limit. Adding payload to "increase stability" does not authorize the launch, and the wind figure is not a suggestion.
That no-go survives a vehicle that would otherwise fit §107.25. A sparsely populated road does not raise the manufacturer's wind number. Gusts above the listed resistance are a reason to stay on the ground, whether the pilot is standing or riding.
Picture the legal shape, then the illegal one. A remote pilot in an open ranch truck, over empty rangeland, not carrying anyone else's property for hire, keeping the aircraft in sight at 40 knots groundspeed, inside the wind limit, is using the §107.25(b) conditions. The same pilot pacing at 92 knots, or turning into a crowded marina, or launching into 24 mph gusts against a 22 mph limit, has left the operation.
Try the moving-vehicle items in the free practice test. The course lessons that place §107.25 next to speed and operations over people are at pricing.