Runway Threshold Markings
Airport Runways & Infrastructure · 4 specs
Direct Answer
Runway designations reflect their magnetic azimuth heading divided by 10 (e.g., 094° rightarrow Runway 09, 274° rightarrow Runway 27), while the number of longitudinal threshold stripes (piano keys) strictly indicates the runway width.
Specs
| Standard Authority | FAA AC 150/5340-1M / ICAO Annex 14 |
| Runway Number Orientation | Magnetic heading rounded to nearest 10 degrees (01 to 36) |
| Parallel Runway Letters | L (Left), C (Center), R (Right) |
| Threshold Stripe Dimensions | 100 ft (30 m) length, 5.75 ft (1.8 m) width per stripe |
Runway Orientation Numbering & Azimuth System
Runway numbers correspond to the magnetic azimuth of the runway centerline divided by 10 and rounded to the nearest integer:
- Azimuth Math: A runway oriented along 274° magnetic is numbered 27. A runway along 094° magnetic is numbered 09.
- Reciprocal Runways: Opposite ends always differ by 180° (18 units), e.g. Runway 09/27, 04/22, 16/34.
- Parallel Runways: Parallel runways receive lateral suffix designators from left to right from the approaching pilot's perspective:
–2 Parallel Runways:
L(Left),R(Right) –3 Parallel Runways:L(Left),C(Center),R(Right) –4 Parallel Runways: One pair shifted by 10° (e.g.27L/27Rand28L/28Rat LAX/ORD) orL,LC,RC,R.
ICAO / FAA Standard Threshold Stripe Counts by Runway Width
| Runway Width (Metric) | Runway Width (Imperial) | Number of Threshold Stripes | Stripe Width & Gap Standards |
|---|---|---|---|
| 18 m | 60 ft | 4 stripes | 1.8 m (6 ft) wide stripes; 1.8 m spaces |
| 23 m | 75 ft | 6 stripes | 1.8 m (6 ft) wide stripes; 1.8 m spaces |
| 30 m | 100 ft | 8 stripes | 1.8 m (6 ft) wide stripes; 1.8 m spaces |
| 45 m | 150 ft | 12 stripes | Standard precision instrument runway |
| 60 m | 200 ft | 16 stripes | Widebody / Code F (A380) international runway |
Touchdown Zone, Aiming Point & Displaced Threshold Markings
| Marking Type | Visual Presentation | Longitudinal Distance from Threshold | Operational Purpose |
|---|---|---|---|
| Threshold Bar | Solid white bar 3.0 m (10 ft) wide across runway | Beginning of runway | Marks start of usable runway for landing |
| Touchdown Zone (TDZ) | 3-bar, 2-bar, 1-bar longitudinal white rectangular pairs | Every 150 m (500 ft) | Distance awareness during touchdown rollout |
| Aiming Point | Two solid broad white bars 45–60 m long | 300–400 m (1,000–1,300 ft) | Visual aiming target for instrument glide path |
| Displaced Threshold | White arrows pointing along runway centerline | Variable (100–500 m) | Usable for takeoff and rollout; landing prohibited before bar |
| Blast Pad / Stopway | High-visibility yellow chevrons pointing toward threshold | Pre-threshold overrun | No aircraft operations permitted; overrun absorption |