FRG Tower Controller reported an aircraft went past the threshold and into the runway safety area just as another aircraft was about to land; causing a loss of runway separation. ATC informed the landing aircraft to go around; but the landing aircraft was already in the flare and could not go around. The reporter stated there have been numerous runway incursions at Taxiway G4/Runway 19 intersection since the airport had construction done a few years prior that reduced space between Taxiway G4 and the hold bar. General aviation pilot flying reported being notified of aircraft nose crossing the runway line but believed that had not occurred.
Synopsis
FRG Tower Controller reported an aircraft went past the threshold and into the runway safety area just as another aircraft was about to land; causing a loss of runway separation. ATC informed the landing aircraft to go around; but the landing aircraft was already in the flare and could not go around. The reporter stated there have been numerous runway incursions at Taxiway G4/Runway 19 intersection since the airport had construction done a few years prior that reduced space between Taxiway G4 and the hold bar. General aviation pilot flying reported being notified of aircraft nose crossing the runway line but believed that had not occurred.
Narrative
I was the On-the-Job Training Instructor (OJTI) responsible for Local Control. Runway 19 was in use and things were normal. Aircraft Y was over the runway; PAST the threshold when Aircraft X crossing into the Runway Safety Area (RSA) and came to a stop partially over the edge line of Runway 19 at G4 intersection; to the immediate forward left of Aircraft Y. This happened without warning and was an immediate loss of runway separation; as Aircraft Y was past the threshold and very low over the runway. My trainee yelled 'stop that guy' in reference to Aircraft X; as is often the case in a situation like this. I said 'not that' as my trainee quickly switched to trying to send Aircraft Y around. My trainee started with 'Aircraft Y over the runway; go around' but also used Aircraft Y's callsign in the same/a repeated instruction at the end. Aircraft Y said they couldn't go around; so I advised them of the traffic over the edge line to their forward left; which the pilot acknowledged seeing. Aircraft Y touched down in close proximity to Aircraft X and almost certainly rolled past them on the ground. At the time of the runway incursion; Aircraft Y was past the threshold; and in the flare. After the event; the pilot of Aircraft Y advised that he 'was committed to the landing and unable to go around.' The touchdown zone on Runway 19 is before the G4 intersection and with different timing a collision was certainly possible. Light General Aviation (GA) aircraft often exit 19 at [Taxiway] B3; which is directly across from G4 and are almost always on the ground by G4. Unfortunately; from the Local Control perspective; there isn't really anything we could do with this sequence of events/timing to prevent the situation. Ground Control did not see Aircraft X violate the RSA in time to stop them. When Ground did try to stop Aircraft X; they were already in the RSA; but did not respond to instructions to stop. After we attempted to send Aircraft Y around on Local Control; we reached out to Aircraft X and they were on Tower frequency but never checked on. This is the second runway incursion at this location in just over a week. The same thing happened at G4 on Day 0 at the same location with Runway 19 active. The only difference on Day 0 was that the arriving aircraft had not yet passed the threshold and was able to go around. In both instances; I'm relatively sure that the pilots of the violating aircraft were not based here or local. Furthermore; this runway incursion has occurred multiple times over the years I have been here. The FBO's Ramp has multiple taxiway stubs/intersections that DO NOT CONNECT to a parallel/main taxiway and are VERY SHORT; pretty much only existing after the hold bar. Prior to a few years ago; the RSA was smaller and there was more Ramp space around these intersections.A few years ago; Runway 01/19 underwent construction for RSA issues. Among many changes; the Golf-side taxiways had their hold bars moved to the correct; further away RSA. This took away from the Ramp space that was there; shortening the available space to move before an aircraft would reach the RSA. The taxiways in question are G2; G3 and G4. Taxiway Golf starts at G5 and runs parallel to Runway 01/19. The reason why G4 is always an issue is that it is directly abeam the FBO Ramp. Aircraft utilizing G2 or G3 are typically the ones parked near them; and are almost always FRG-based aircraft. G4; on the other hand; is in line with the front of the FBO hangar; and aircraft are almost always parked nose-in to the hangar. When these aircraft start up and call for taxi; they are waved left - west - by marshallers; turning toward the runway and away from the hangar. With transient aircraft; this points them right at G4; with limited time and space before they reach the hold bar. We; Organization and Management at the local level; have brought this issue up with Airport Operations multiple times over the years; but have not had any success mitigating the issue. We have asked for it to be a hot spot and asked for guard lighting. Recently; both of those steps were taken for the Bravo/Alpha intersection due to runway incursions onto Runway 01. In all of my years at FRG; I believe G4 has had more issues and definitely should get the same treatment. Irrefutably; this problem has occurred twice in a very short amount of time. The layout is somewhat unusual and the only spot it occurs at FRG. Pilots go from non-movement area to RSA/'on the runway' in a matter of feet; with only a few lines of paint separating them - hold bar.
Second reporter narrative
At XA:20 in preparation for departing; after receiving taxi instructions from the FBO; I departed [the] FBO onto Gulf 4 taxiway to proceed to Runway 19. I saw the 'hold short line' for Runway 19 almost immediately after entering G4. I applied my brakes and stopped short of the runway. I was told to hold short of the runway. I was then told to cross 19 and turn right onto Bravo to then hold short of l9.As I waited; I was told to call the Tower either before departing or after landing at my destination. I elected to depart when permitted and fly to my destination at ZZZ. I then called the Farmingdale Tower and was told that the nose of my aircraft crossed the runway line. I had seen the incoming plane land without any difficulty. The Tower then said this problem had occurred just the previous week because of the short length of Taxiway G4 from FBO to Runway 19. The Tower said the FAA had been notified the previous week of this same problem. I felt strongly that the nose of my aircraft never crossed the runway line prior to being cleared across.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.