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I wonder if some kind of "TCAS" for runways can be implemented - once the controller clears an aircraft for a given runway, some antennas start broadcasting tha

I wonder if some kind of "TCAS" for runways can be implemented - once the controller clears an aircraft for a given runway, some antennas start broadcasting that aircraft's identifier so any equipped planes approaching the runway can tell whether they've been cleared for it. For planes on approach, the existing ILS antennas can be reused but I'm not sure whether that will work on the ground - do the ILS antennas cover enough of the ground to accurately target a plane that's approaching the runway perpendicularly (off a taxiway, etc)?

t0mas88 3y ago
Two types of systems already exists on the ATC side of things. There are red stop-bar lights at each runway entry point. Pilots are trained never to cross a red stop-bar even if told by ATC. The controller has to press a button to turn the lights off, and they automatically come back on after 1 plane has passed the lights. In larger airports with an automated system, the system monitors the runway occupancy and approach sector. If the runway is occupied or an aircraft is on final within a certain distance, the system throws an alert before the stop-bars can be turned off. On top of that there is also an autonomous version of this system that will use red lights to indicate a dangerous runway status (e.g. aircraft on approach) at each entry point. And the other way around, an aircraft line up for takeoff (but holding) will get red lights if any of the entry points further down the runway are crossed. More here: https://skybrary.aero/articles/autonomous-runway-incursion-warning-system-ariws https://skybrary.aero/articles/autonomous-runway-incursion-w...
- t0mas88 3y ago
  I can't edit this comment anymore, but there has just been an update that the stop bar lights I describe above were out of service at the airport in this incident.
__m 3y ago
ASDE-X should warn the controller, not sure if it's installed at that airport
- asystole 3y ago
  I'm in the realm of pure speculation here, but does ASDE-X to some extent rely on a/c having mode B transponders, which I've seen people saying the coastguard Dash-8s didn't have? If this is the textbook runway incursion it appears to be then it does seem incredible it wasn't caught by runway safety systems.
  - Nextgrid 3y ago
    I wonder if another system can use lasers/light beams to detect obstructions on the runway? Rather than relying on vehicles actively reporting their positions (which can malfunction, and as far as I know only aircraft are equipped - cars/trucks/snow clearing vehicles don't have it), it would instead just check whether there's anything on the runway and alert the controller (and ideally any approaching planes via the ILS antennas) that the runway is obstructed?
wlonkly 3y ago
Something like "TCAS for runways" is RIMCAS[1], but it notifies the controller, not the pilots. [1] https://www.indracompany.com/sites/default/files/indra06-nova-9000-rimcas.pdf https://www.indracompany.com/sites/default/files/indra06-nov...

t0mas88 3y ago

Two types of systems already exists on the ATC side of things. There are red stop-bar lights at each runway entry point. Pilots are trained never to cross a red stop-bar even if told by ATC. The controller has to press a button to turn the lights off, and they automatically come back on after 1 plane has passed the lights. In larger airports with an automated system, the system monitors the runway occupancy and approach sector. If the runway is occupied or an aircraft is on final within a certain distance, the system throws an alert before the stop-bars can be turned off. On top of that there is also an autonomous version of this system that will use red lights to indicate a dangerous runway status (e.g. aircraft on approach) at each entry point. And the other way around, an aircraft line up for takeoff (but holding) will get red lights if any of the entry points further down the runway are crossed. More here: https://skybrary.aero/articles/autonomous-runway-incursion-warning-system-ariws https://skybrary.aero/articles/autonomous-runway-incursion-w...

t0mas88 3y ago
I can't edit this comment anymore, but there has just been an update that the stop bar lights I describe above were out of service at the airport in this incident.

__m 3y ago

ASDE-X should warn the controller, not sure if it's installed at that airport

asystole 3y ago
I'm in the realm of pure speculation here, but does ASDE-X to some extent rely on a/c having mode B transponders, which I've seen people saying the coastguard Dash-8s didn't have? If this is the textbook runway incursion it appears to be then it does seem incredible it wasn't caught by runway safety systems.
- Nextgrid 3y ago
  I wonder if another system can use lasers/light beams to detect obstructions on the runway? Rather than relying on vehicles actively reporting their positions (which can malfunction, and as far as I know only aircraft are equipped - cars/trucks/snow clearing vehicles don't have it), it would instead just check whether there's anything on the runway and alert the controller (and ideally any approaching planes via the ILS antennas) that the runway is obstructed?

wlonkly 3y ago

Something like "TCAS for runways" is RIMCAS[1], but it notifies the controller, not the pilots. [1] https://www.indracompany.com/sites/default/files/indra06-nova-9000-rimcas.pdf https://www.indracompany.com/sites/default/files/indra06-nov...