There is a optical phenomenon that relates to two objects that are on a collision course with each other known as 'Static Convergence Illusion'.
A mid-air collision or even a ground collision between two vehicles can be determined well in advance with tremendous accuracy by simply noting any change in the relative positions of each object while viewing that converging object through the glass of your windshield.
If you are inside the aircraft or vehicle and you notice the other craft moving ACROSS your windshield, you WILL NOT collide with that other craft because it is NOT on a collision course with you, since it's relative position is constantly changing on your windshield as it moves from left to right for example.
But if that other craft does not move on your windshield because it appears stationary as you BOTH move toward each other from ANY angle, you are on a collision course with that other craft.
This can better be described as the other craft appearing as an insect strike on your windshield, but as you get closer and closer to each other, that tiny spec on your windshield suddenly gets larger and larger, but does so without changing it's relative position on the glass of your windshield.
I believe that the helicopter's pilot simply did not notice the jet in front of him despite voice recordings confirming that the helicopter pilot had the jet in sight, only because those lights of the jet would NOT have moved on the glass of the helicopter pilot's windshield, which is why they collided... they were on a collision course and the jet would have appeared as a non-moving spec or smear on the helicopter pilot's windshield until both aircraft impacted with each other.
