For most UAS, they reach their maximum height of 400’ from the TO point. That said the vast majority of UAS are using barometric pressure to assume altitude. With that in mind, the pilot taking off from a ‘cliff edge’ and flying over the cliff (example altitude now 400’+) would seemingly place the UAS pilot in violation of the 400’ max altitude. But, the max altitude is measured from the TO land surface to the UAS, not pilot to UAS. The barometric pressure may change while in flight to indicate differing altitudes. The sensors used in our drones are quite similar to sensors in larger manned AC. The sensors are generally protected by being placed internal. They are designed to microscopically detect the differences of air pressure. So a setting of assumed ZERO AGL air pressure will change as the UAS increases/decreases altitude. These sensors are NOT alone in their reporting of altitude. Many UAS have the built in GPS and are constantly receiving the broadcast signals. The GPS receivers, within the UAS, work in conjunction with the barometric pressure sensors to keep your drone in a level, controlled environment. This is essentially why, when flying, one’s UAS may report an altitude change when you go straight out from the mountain cliff you may be standing on. It is entirely possible at that particular time, you have not violated the AGL, as once again, the AGL is generally based on TO location.
Did I get it wrong?
Did I get it wrong?
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