Lets take a Phantom 4 'drone' or UAV. (or even call it a remote piloted aircraft RPA). The battery life is approximately 25 minutes give or take, depending on weather/wind, and battery conditions. The DJI RPA's have what is called 'Return to home' which will return it to the take-off point or 'home point location' if signal is lost (ie transmitter fails, connection is lost with the controller or the battery reaches a pre-set level). The RPA weighs in the region of 1.3kg, being generally plastic in nature except for the battery and the very small electric motors.
To climb to 11'000 feet is perfectly achievable. The problem is it quickly becomes invisible to the naked eye. The operator certainly cant fly a 30mph RPA at or toward an airliner as a) they'd need to have superpowers of sight (even with a 'first person view' system utilised)
b) there is no way at that distance it could be flown 'at' an airliner doing what? 200mph? It would be a stroke of luck to get close to one unless you went out with the intent of only flying where you knew aircraft were going to be, within your time scale of battery life, and even then its a big old sky up there. How two pilots in an airliner, preparing for a descent etc, are looking out of the window at that exact point, running through checklists, frequency changes, and generally just doing what pilots do, i'm amazed they even see anything outside, unless of course airline pilots spend their entire flight looking out of the cockpit windows???
Remember we are talking about a very small 'drone' (I hate that name) and it will be virtually standing still at that level or at the very least being blown off course due to the fact it cant do more than 40mph in sport mode. (arent the wnds aloft higher than that? )
I fly professionally and tend to be low level most of the time <3000' and relatively slow, and have never seen an RPA in flight yet. Oh and I have an RPA permit from the UK CAA, so I believe I do talk with some sense regarding the subject.
So far, there has been no reported instance of a drone definitely hitting an aircraft. Reports yes, proof no. Now since 1990 there have been nearly 200 plane-turtle strikes. (ok thats in the USA) but even so, there are probably more aircraft over there ( and obviously more kamikaze turtles).
As a responsible RPA operator and professional pilot, I honestly believe this whole thing is being slightly over-hyped. As I said above, the winds alone would mean the RPA would be struggling unless at 11000' the wind was less than 40mph? Not likely. The drain on the battery would be exceptionally high just trying to maintain position, even if it were possible. I certainly don't condone the use of RPA's outside of the 'Drone Code' limits of 400' high and 500m, and generally, the educated in the drone community won't either. Unfortunately there will always be those who think its big and clever to see how far they can go. Whether its distance or height, and I know of distances of 8 miles being reached by a phantom 4, and also heights in excess of 3000'. 11000' might be pushing it.
In future, when a drone is reported as being 'flown' in the vicinity of an airliner, check the winds at that height, if its more than about 25-35kts, the RPA is very unlikely to be under anyones control, (it just isnt possible to control it when the wind exceeds the RPA capability) and will be drifting downwind, albeit trying to fight its way back to where it should be, and in the process using batteries at max rate.
Oh and someone above mentioned gliders. I've had more near misses with them than anything else. !!!
Last edited by helimutt; 10th Dec 2016 at 16:12.