Side-by-Side Comparison
Airport Runways & Infrastructure
PAPI & VASI Lighting vs. Runway Threshold Markings
Comparing 2 standards across 8 specifications. 8 key differences identified.
Comparing:
PAPI & VASI Lighting
Runway Threshold Markings
The Precision Approach Path Indicator (PAPI) and Visual Approach Slope Indicator (VASI) provide visual glide slope guidance on final approach using color-transition optical lenses: 4 White (Too High), 2 Red / 2 White (On 3.0° Slope), and 4 Red (Too Low).
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.
Specification Comparison Table
8 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Approach Angle
|
3.0 degrees standard (up to 5.5° on steep approaches like London City EGLC) | — |
|
PAPI Array Layout
|
Single row of 4 light units perpendicular to runway on left side | — |
|
VASI Array Layout
|
2 or 3 bars of lights in tandem (Upwind / Downwind bars) | — |
|
Visible Range
|
5 miles (8 km) by day, up to 20 miles (32 km) at night | — |
|
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 |