Drones may not necessarily have an apparent educational benefit to a school, however as they are becoming more commonplace and affordable they are being grouped with useful equipment for the school like a camera was many years ago
With the ability to spend less than a thousand dollars to get a drone with over Full HD recording capabilities and high resolution still shots it can be a valuable asset to the school to record school events such as athletic carnivals or even compliment your special events with those aerial shots you could not replicate otherwise. A few popular devices include the DJI Phantom series and the Parrot Bebop series starting below $1000.
Be mindful of usage as there are strict laws regarding the use of these devices. Plan ahead and mark off areas where the drone can be used as you must not fly closer than 30 metres to vehicles, boats, buildings or people. Laws will differ depending on your country, for Australia laws will apply so make sure you check what applies to you. For Australia https://www.casa.gov.au/modelaircraft.
Otherwise some ideas used by other schools have been surveying for HSIE classes, science classes with attached atmospheric sensors,video projects and of course coding. For programming the Lego Mindstorm NXT drones and the Parrot rolling spider drones are very popular and affordable starting at a bit over $100. Both include visual programming languages to interest students in coding and robotics.