Standard & Basic Configuration
Rule note
Applicability, configuration, position and performance rules are never mixed across standards — e.g. an ICAO position rule is never combined with an FAA quantity rule.
Rule note
RGL and Stop Bar are connected but never assumed to substitute for one another (see Calculator #10).
Applicability
Rule note
RGL is not automatically installed at every runway intersection — applicability depends on the selected governing standard and the airport operating configuration. Select the outcome per the applicable document; the exact ICAO/FAA applicability criteria are not hard-coded in this build.
Function, Colour & Flash Operation
Rule note
RGL is reported as a warning/conspicuity system, never as general runway lighting.
Rule note
Flash characteristics come from Standard → RGL Type → Flash Characteristic — arbitrary user-defined flash timing is not accepted into the compliance calculation.
Configuration & Quantity Engine
Rule note
The applicable geometry loads automatically from this selection — do not assume the in-pavement quantity equals the elevated quantity.
Rule note
Distance from the taxiway centreline to each elevated housing. Elevated RGL housings stand outside the taxiway edge, so the value must exceed half the taxiway width. The 14.5 m default is illustrative for a 23 m taxiway (3 m clear of the edge). Left = left when facing along the taxiway heading toward the runway.
Rule note
One elevated housing may contain multiple optical sources — housing count, optical-source count and physical-assembly count are reported separately below.
Taxiway Centreline Reference & Intersection Geometry
Rule note
PCL is the taxiway centreline / runway intersection reference point. Every RGL position is calculated relative to PCL, then transformed into airport coordinates using the taxiway heading — the RGL line is set out square to the taxiway centreline; the intersection angle is recorded only. A simplified, clearly-documented model, since the exact position/spacing database is project/standard-verified.
Rule note
Taxiway/runway intersections are not always 90°. θ is recorded for the schedule and report only: the RGL line is always set out square (90°) to the taxiway centreline, so it does not rotate with θ.
Rule note
Separate from the left/right symmetry tolerance. If left blank the symmetry tolerance T is used and the result is shown as provisional.
Duplicate-Position Handling & Display
Rule note
Generated positions are auto-checked pairwise against the symmetry tolerance T.
Existing-Installation Inspection (optional)
Rule note
ICAO Annex 14: 30 to 60 flashes per minute for each light, with equal lit and unlit periods and the lights of a unit illuminated alternately. Enter the figure from your governing document or the fixture specification; the value is not auto-filled.
Electrical Test Record (optional)
Inspection results
Report details
Coordinate schedule & BOQ
Coordinate Schedule
RGL BOQ
| Item | Quantity |
|---|---|
| Elevated RGL assemblies | — |
| In-pavement RGL assemblies | — |
| RGL control/interface | — |
| Monitoring interface | — |
| Associated accessories | — |
| Total physical assemblies | — |
RGL quantity is never reported as equal to Stop Bar quantity — these remain separate systems with separate functions and separate counts.
Stop bar relationship
Build-up
How This Calculator Works
Standard → Applicability → Configuration → Position Engine → Stop Bar/Holding Relationship → Quantity → Compliance. RGL is never auto-installed, never assumed equal to Stop Bar quantity, and never given an arbitrary user-defined flash characteristic.
Stop Bar ≠ RGL
Stop Bar = controlled clearance/holding indication. Runway Guard Light = conspicuity warning of a runway intersection. They are functionally distinct, standard-database-distinct, and quantity-distinct — this calculator never derives one from the other.
Applicability before quantity
The first calculation is applicability (Required / Recommended / Not Required / Project-Specific / Engineering Review), not quantity. RGL is not automatically installed at every runway intersection — applicability depends on the governing standard and the airport's operating configuration, entered explicitly rather than assumed.
Elevated vs. in-pavement quantity
Worked example (in-pavement, illustrative): L = 23 m, Sdesign = 3 m → N = 8 spaces, Sactual = 2.875 m, 9 lights (one at each end of the coverage length). The in-pavement quantity is never assumed equal to the elevated quantity — each configuration loads its own geometry.
Left/right symmetry
Checked against the symmetry tolerance T. A configuration is reported symmetrical or asymmetrical based on this measured difference, not assumed from the configuration type alone.
Local → airport coordinate transform
PCL is the taxiway centreline/runway intersection reference. Every RGL position is generated relative to PCL in local coordinates, then transformed using the taxiway heading. The RGL line is always set out square (90°) to the taxiway centreline; the intersection angle θ is recorded for reference only. A simplified, explicitly-documented model (not a published standard table); local X is positive to the left when facing along the heading.
Flashing frequency test
The allowable deviation tolerance is entered from the applicable standard rather than hard-coded — left blank, the deviation is reported without a PASS/FAIL verdict.
Standard-specific database
| Standard | Applicability | Position/Quantity |
|---|---|---|
| ICAO Annex 14 | Project-entered | Project-entered |
| FAA AC 150/5340-30J | Project-entered | Project-entered |
| DGCA / Indian implementation | Project-entered | Project-entered |
No figure is assumed by default — the exact ICAO/FAA RGL configuration and position/spacing database are not incorporated in this build.
ICAO Annex 14 reference (advisory, not auto-applied)
| Item | Basis |
|---|---|
| Configuration A | Elevated; a pair of alternately flashing yellow lights each side of the taxiway, at the holding position |
| Configuration B | In-pavement; yellow lights at 3 m intervals across the taxiway, adjacent lights alternately lit |
| Config A required | RVR < 550 m with no stop bar; RVR 550 to 1,200 m where traffic density is heavy |
| Stop bar | Config B shall not be collocated with a stop bar |
| Flash rate | 30 to 60 per minute per light, equal lit/unlit periods |
Summary for orientation only. Confirm against the current Annex 14 Vol I edition and the DGCA implementation before relying on it.
Housing vs. optical source vs. physical assembly
One elevated housing may contain multiple optical sources. This calculator reports housing quantity, optical/light-source quantity, and physical assembly quantity separately, preventing procurement confusion between "2 housings" and "2 lit surfaces" when a housing contains more than one source.
Combined Stop Bar / RGL configuration
| Configuration | Status |
|---|---|
| RGL without Stop Bar | Standard/project review |
| Stop Bar without RGL | Standard/project review |
| RGL + Stop Bar | Applicable combined configuration |
Electrical & flashing inspection fields
Supply voltage, current, insulation resistance, earth continuity, circuit ID, control panel ID and operating status are captured as an inspection record alongside the design calculation — making this tool usable for field verification, not only new design.
What this calculator does not do
It does not maintain the exact ICAO or FAA RGL configuration/applicability tables, does not resolve the exact position/spacing database, and its intersection-angle coordinate transform is a documented simplification rather than a published standard formula. Applicability engine, configuration-specific geometry, symmetry, Stop Bar relationship, and quantity distinctions are fully calculated; exact figure-level configuration must be confirmed against the approved layout.