Boston, MA
The Federal Aviation Administration (FAA) operates a prototype Runway Status Lights (RWSL) system at Boston Logan International Airport (BOS).
Runway Status Lights indicate when a runway is unsafe to enter, cross, or take-off through the use of in-pavement red lights installed at selected intersections and runways as described below.
RWSL convey the runway occupancy status, indicating when a runway is unsafe to enter through the use of red in-pavement warning Runway Entrance Lights (REL) and when it is unsafe to take off through the use of red in-pavement warning Takeoff Hold Lights (THL).
REL are a series, typically 6, 7, or up to 20 or more, of red in-pavement lights spaced evenly along the taxiway centerline from the taxiway hold line to the runway edge. One REL is placed just before the hold line, and one REL is placed near the runway centerline.
REL are directed toward the runway hold line and are oriented to be visible only to pilots and vehicle operators entering or crossing the runway from that location.
REL are operational at the following intersections at BOS:
Runway 4L/22R
Taxiways K and E (East and West Side)
Runway 4R/22L
Taxiway E (East Side)
Runway 9/27
Taxiway C (Northwest Side)
Runway 15R/33L
Taxiway D (Southwest Side)
THL are a series of red in-pavement lights at 100-foot spacing along the runway centerline.
THL are directed toward the approach end of the runway and are visible to pilots in position for takeoff or just commencing departure roll.
There are two sets of THL on the following runways at BOS:
Runway 9
16 pairs (total of 32 lights)
Runway 15R
16 pairs (total of 32 lights)
When operating at airports with RWSL, pilots will operate with transponder "ON" when departing the gate or parking area until arrival at the gate or parking area. This ensures interaction with the FAA surveillance systems which provide information to the RWSL system.
Runway Status Lights indicate runway status only. They do not substitute for an ATC clearance. Pilots are still required to receive an ATC clearance for any operation on the runway.
Pilots are encouraged to learn more about the RWSL system at:
http://www.faa.gov/air_traffic/technology/rwsl/