October 2019

Total	Highly Unlikely	Unlikely	Possible	Likely	Highly Likely
15	1	12	2	0	0

Airprox #	Score	Rating	Details	ARC Comment
2019203	-30	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone between 6000ft and 9000ft is infinitesimal, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than two minutes at 6000ft. No consumer drone could reach 9000ft in real world conditions.	Location was in the area of London Heliport (Battersea). Sighting was most likely of a helicopter. London Heliport confirmed they have never seen a drone in their airspace, nor has any helicopter pilot ever reported a drone to them. Airliner pilots have been shown to mistake helicopters for drones previously.
2019204	-20	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 3,000ft is very small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than six minutes at 4000ft.	Location and starboard side spotting would mean a clear view of any traffic departing Northolt RW25 and circuit traffic at Denham. Denham traffic probably not ADS-B equipped.
2019205	0	ARC considered it possible that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence.	Empirical data from ground sensors shows that no DJI drone was present in this location at or around this time. ARC are in contact with the owners of this official data and provided it to UKAB some weeks prior to publication. UKAB never made contact with them and published a demonstrably false airprox report regardless.
2019211	-10	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 1,640ft is small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	No sign of Dash 8 on ADS-B. Reported time may be inaccurate (as in several other airprox reports).
2019213	-10	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 1,640ft is small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	Location was immediately (200m) South of London Wetlands Wildlife Centre, haven for migratory large wetland birds. The LWWC has a strict ‘no drone’ policy and is warden patrolled. Their representative could barely contain themselves when told that this area was aUK hotspot for drone sighting claims. It is also where H3, H7, H10 and H4 Helicopter routes converge. ADS-B analysis shows that reporting a/c had a CL35 9H-VCN business jet pass in front of them at 15,500 feet above, from left to right, at the reported time.
2019214	-20	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 3,000ft is very small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than six minutes at 4000ft.	UKAB classified this as ‘Unknown Object’. ADS-B analysis shows that there was no A321 on final approach to Manchester 10 minutes either side of the reported time. UKAB should check movement logs/ radar to confirm the reporting aircraft was actually present at the time and date reported. (There have been previous instances where the reported time was 2 hours wrong).
2019219	-10	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 1,640ft is small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	EV97 not visible on ADS-B. Not unusual for microlight not to be ADS-B equipped. No helicopters on ADS-B as is usual. Statement of ‘Drone’ with no type or number of rotors, etc. As per UKAB’s stated methodology this should be classified as an ‘Unknown Object’.
2019222	-20	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 3,000ft is very small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than six minutes at 4000ft.	ADS-B does not show PA28. Not unusual for older GA aircraft not to be ADS-B equipped.
2019223	0	ARC considered it possible that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence.	R44 does not show on ADS-B. Which is not unusual. The word ‘Drone’ is used. The type or number of rotors is not mentioned. As per UKAB’s methodology this should be classified as an ‘Unknown Object’.
2019232	-30	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone between 6000ft and 9000ft is infinitesimal, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than two minutes at 6000ft. No consumer drone could reach 9000ft in real world conditions.
2019234	-5	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 400ft is reduced, as DJI products (75% market share) feature a 400ft (121m) height limit warning and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	ADS-B shows blue and white PA31 travelling North to South crossing just East of Coningsby a few minutes later than the reported time. Typhoon does not show on ADS-B so we were unable to confirm the exact time it was present at the location (UKAB airprox times have been shown to be up to 2 hours out previously). Given the pilot reported no risk of collision it seems strange that this was classified as ‘Medium’ risk.
2019235	-160	ARC considered it highly unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. The location (more than five miles offshore) makes encountering a drone totally improbable.No photographic evidence. The likelihood of encountering a drone above 12000ft is effectively zero. These heights would be impossible for consumer drones due to the technical limitations of battery energy density / mass. A drone built specifically for the task is not inconceivable, however the likelihood is very small. If possible at all, loiter time at this altitude could only be a few seconds. It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. The object encountered is described as a “Drone” but with no further details. The wind strength (between 25 and 40km/h at ground level) would make drone operations difficult, and would significantly reduce the range and heights achievable.The wind strength (above 72kmh/h at reported level) would make drone operations impossible.	25,000ft and 27km offshore. 123km/h wind at that altitude at that time and location. The location, height and wind speed are all outside drone operational capabilities. The reporting a/c had another aircraft, G-STBK (B77W) – Flight BA8, Tokyo to LHR, 13.57 miles ahead of it on a slightly more southerly course. So the reporting aircraft, heading due West, passed to the right of it.
2019239	-40	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone between 9000ft and 12000ft is effectively zero. These heights would be impossible for consumer drones due to the technical limitations of battery energy density / mass. A custom-built drone could possibly achieve this level but they account for less than 3% of the fleet*. If possible at all, loiter time at this altitude could only be a few seconds. It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	Almost certainly impossible. 61km/h winds at that height and location on that day. A drone could certainly not achieve that height, in that wind.
2019240	-20	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 3,000ft is very small, as DJI products (75% market share) feature a 1,640ft (500m) hard height limit and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit. Furthermore, the technical limitations of battery energy density / mass would mean that any drone that was able to reach these heights would have a very short loiter time – less than six minutes at 4000ft.	Location coordinates are for a point 1km South of London Heliport (Battersea) – which means helicopter traffic would be to the right of the reporting a/c, and below. The London sightseeing helicopters are orange – which could easily appear beige depending on the lighting. And the fuselage when viewed from above is effectively rectangular. UKAB should request movement logs etc for London Heliport around the time/date. Heathrow ATC do not inform inbound aircraft of London Heliport traffic and traffic using H10, H7, H3, H4 and airline pilots have been shown to mistake helicopters for drones previously. Wind 44km/h at level.
2019244	-5	ARC considered it unlikely that the object observed was a drone.	This is an eyewitness report from the aircraft flight crew only. There is no corroborating evidence. No photographic evidence. The likelihood of encountering a drone above 400ft is reduced, as DJI products (75% market share) feature a 400ft (121m) height limit warning and Yuneec products (second largest market share with 5%) feature a hard 400ft (121m) height limit. (Most of the drones in the remaining 20% are toys which would be incapable of reaching this height or racing drones which are flown within a few feet of the ground.) It would also require the drone pilot to be willing to fly the drone illegally above the 400ft legal height limit.	The base leg for RW23 at Coventry is to the E / N/E of the airfield, in the vicinity of Wolston village.These ‘warnings’ are from the Pooleys entry for Coventry: Warnings: Radio controlled aircraft activity 3 nm to east, 0.5 nm SE of Wolston Village. Intensive bird activity to the North and Northeast of aerodrome. The flying field to the SE of Wolston is the home of the very active Coventry and District Model aircraft Club (CADMAC). The fact that the Instructor was setting the a/c up for the landing approach on base leg implies that the student was either on a trial flight or was at a very early stage of training. It would be wrong to attach too much importance to the accuracy of the ‘200feet below’ estimation – or to the a/c reported height of 900ft (as it would be descending on base leg). It is entirely possible that the drone (or model a/c or bird) was below 400feet agl. So we have a very inexperienced observer (student) reporting having spotted a drone 200feet below them, when in the location where there is a specific warning that model aircraft and birds are likely to be seen. How does this qualify as an airprox? This report could be filed on every circuit on a nice day when the modellers are flying.