Product Details & Technical Spec

The PAPI (Precision Approach Path Indicator) system is a simple and efficient, positive visual aid to the pilot on final approach. The PAPI system consists of a line of four units at 90˚ to the runway centre line which are typically spaced at 9 metres apart. Units are identical, producing a beam of light with the upper portion white and the lower red. A pilot sees the four individual lights in a combination of red and white, depending on his vertical position. Typically the elevation settings of each unit vary by 20 minutes of arc, the nominal 3˚ glideslope angles being midway between the centre pair. The system is easily set for other glideslope angles. Using a PAPI system it is possible to follow the glideslope to less than 300 metres from touchdown (approximately 15 metres height).

Features & Benefits

The Research Engineers PAPI unit is modular in design and features interchangeable PAPI projectors, facilitating low cost maintenance of the airfield installation. The option of servicing Research Engineers PAPI projectors in the workshop results in minimum runway shut-down time. re-lamping projectors is also a very simple task. The cost of life of Research Engineers’ PAPI system is the least expensive on the market.

PAPI slope angle is set quickly and simply using three legs. The front legs of the PAPI level the unit laterally whilst the rear leg provides the elevation adjustment. Corrosive resistant construction using light alloys and stainless steel make Research Engineers PAPI a robust device. The simple design and optical efficiency make this a first class choice of PAPI for the international aviation world.

The modular concept

Interchangeable Projectors – Simplifying maintenance & spares management.
Minimal Field Maintenance – Individual projectors can be replaced in seconds.
Stable Reference – Projectors are mounted on a precision base plate.


  • Precision spirit level with micrometer screw adjustment
  • Calibrated in degrees and minutes
  • Overall accuracy better than 1 minute of arc
  • Operating range from -50 C to +70 C
  • Supplied in protective fitted case

Precision Base Plate

  • Available in 2-projector or 3-projector format
  • Rigid and stable in all environmental conditions
  • 3-leg mounting eliminates induced stresses
  • Provides repeatable clinometer location
  • Anodised aluminium alloy construction


  • Azimuth Range: + or – 10 degrees
  • (15 degrees – meeting CAP 168 – also available)
  • Vertical Adjustment: up to 10 degrees
  • Transmission: 2 minutes of arc
  • Filter Transmission: 25%
  • Meets both ICAO and FAA performance specifications
Australian Made