There's a lot of interesting material in the ATC recording.
- Helo pilots felt that it was intentionally staying nearby as it came very close on multiple occasions and did not seem to be trying to evade. They had visual contact most of the time but sometimes had a hard time tracking it against the city lights.
- Pilots initially describe it as a quadcopter but become skeptical of that due to the performance. No one ever gets a very good look at it to confirm.
- It's described early on as having a dim green light. A green light on the drone would be odd for a position light (they did seem to see it from multiple angles) but it seems like a lot of drones have nonstandard lighting.
- CBP pilots say that it is hard to see on night vision goggles and has a low heat signature. NVGs are not necessarily any better than human vision for discriminating dim lights in the city due to dynamic range, so that doesn't necessarily mean anything. The fact that they couldn't seem to pick it out on the thermal camera might mean something interesting if you looked at different drone types.
- The drone was first described as being at about 4k feet and climbing, to around 12k. That's pretty damn high for anything small.
- I don't hear the controller indicating that they had it on radar at any point, the altitudes are all estimates by the helo pilots.
- Pilots felt that it was not being controlled from the ground due to the large distance it covered, beyond line of sight from any one point. By my estimations it covered over 20 miles during the course of the recording. Given the terrain, that it passed over decently high ridges, I don't think it's a sure thing that it was not being controlled from the ground but it would be surprising.
- The CBP helicopter had a hard time getting it on their camera due to its rapid climbing (the cameras on these helicopters are usually under the nose and can't point up very much) and maneuvering that they seemed to feel was intentionally evasive of tracking. But it sounds like they may have successfully captured it on camera at times.
- The speed bit is confusing as no one ever tries to estimate it directly, I think because the drone was seldom flying straight. The article's suggestion that it did 105 knots in airspeed is not unjustified but also not a sure thing. It was definitely somewhere in the 100kts range though, I'd say, based on the difficulty the helicopters had in pursuing it.
- Both helicopters hit their endurance limit as the drone disappeared into clouds. One helicopter was able to stay airborne later and dwelled for a time hoping to see an operator or recovery team on the ground.
- The TPD pilot, speaking after the fact, seemed confident it was not the size of a light aircraft but appreciably smaller.
My analysis:
- Perhaps the most extraordinary thing, I think to the pilots as well, was the way it was maneuvering in such close range to the two helicopters. It suggested not just recklessness but also excellent situational awareness, the kind of thing I have a hard time believing an operator on the ground or by FPV could achieve. It suggests that the operator had help from a targeting system of some kind, whether based on open-source radar/TIS-B/ADS-B or radar on the drone. Visually tracking aircraft over a city at night is already notoriously difficult, even more so by camera, and this thing was coming within 100 feet abeam the helicopters and often flying between them.
- The altitude and speed demonstrated by the drone make me think it's fixed-wing rather than rotor, and fairly powerful. The endurance suggests fuel, not electric. Probably turbine powered.
- It's not at all surprising that a CBP and TPD aircraft were tracking it despite the proximity to the AFB. Most HN users seem to really overestimate the level of security at most military installations, there probably weren't any Air Force acft up at the time or even pilots readily available. Most of the time stuff like this happens at AF bases the response you get is force protection standing in their truck beds with binoculars, not some elaborate air defense operation. Law enforcement conducts far more patrol activity over cities than the military does, and getting an Air Force aircraft in the air would have taken long enough it probably wouldn't have mattered. These kinds of drone incidents are considered more of a civilian matter than a military one anyway as it's almost always just idiots messing around.
- The CBP aircraft at least and probably the TPD helicopter as well will have fairly sophisticated camera packages including thermal. I'm not totally clear on whether or not either of them got useful footage but you hear in the after-action call that the FAA is requesting all the video TPD has. The cameras on these helicopters are designed for tracking things on the ground, not moving fast in the air, so it's unsurprising that they had a hard time capturing it.
- It doesn't mean much that it doesn't seem to have been tracked on radar. Primary radar doesn't consistently detect light aircraft at those altitudes, and this thing was much smaller. In general the US does not have a capability to reliably detect non-cooperative small aircraft, it's just way too expensive to build that out.