The Akasha Colony wrote:With this talk of rotor blade-mounted antennas, would there be any merit to the concept of an end-fire antenna located in the hub fairing?
Lots of the concept designs for LHX and the like had hub fairings of some sort covering the rotor hub itself and some of them were relatively large. It wouldn't provide anywhere near the surface area of a rotor blade antenna, but depending on size it might still provide more space than a mast pod while also providing 360 coverage like the rotor blade.
Also, would there be any utility in adapting some of the optical recognition/rangefinding technologies used in self-driving vehicles to a collision-avoidance system for helicopters?
The loss figures in the study Kyiv posted indicated that the vast majority of losses were to mishaps and mechanical issues and one of the largest factors was accidental collisions or damaging impacts with local terrain or obstacles. A better situational awareness system was identified as desirable and while low-power radars spaced around the aircraft are probably the most straightforward solution (and AFAIK the most common solution for consumer collision alert systems), they might not be desirable for a combat helicopter wanting to control its emissions. Optical and other passive ranging systems though have made strides as of late but I'm not sure how suitable they'd be, especially against small hazards like wires/cables that would be very difficult to spot (and might even be problematic for radar detection). Perhaps a laser system would be a compromise between performance, cost, and detectability, although it would have a limited field of view.
The goal would be to create a system that would alert the pilot if he is approaching too close to an obstacle, especially one outside of his normal field of view. And possibly even include an auto-GCAS feature to react immediately in the event the pilot doesn't react in time.
The drone versions of the KMAX, blackhawk and MH-6 used LiDAR obstacle avoidance systems. It's probably the same technology as the google self driving cars I see around my town that have a visible spinning LiDAR system mounted on the roof. LiDAR ground collision avoidance (GCAS) systems are also quite common on smaller fixed wing UAVs. LiDAR is definetly better for covertness since the beamwidth and sidelobes are much smaller than even a MMW radar. For helicopters LiDAR is also very desirable because it has the resolution necessary to spot power lines that a radar or optical system would find very hard to detect.
Bell's concept V-280 uses an EO/DAS system (with multiple MWIR/LWIR IR imagers placed around the aircraft) connected to an HMD very much like the F-35 that in addition to letting the pilot "see" through the plane can act as a MAWS and I presume also as an optical collision avoidance system. It seems like a system extremely well suited for helicopter/tiltrotor use since it drastically improves situational awareness, something which could certainly help prevent crashes and shootdowns.