wind direction indicator TWI

wind direction indicator TWI


  • visual identification of direction and speed of wind at airports and heliports

Files for download

pdf Data Sheet (1.97 MB)

pdf Certificates SSGA (3.25 MB)

Certificate basis

  • ICAO Annex 14, Vol. 1, 5.1.1
  • FAA Specification AC 150/5345-27 C


  • when air moves with the speed of at least 6 km/hour, the revolving system situated at the top part of the pole on bearing will turn in direction of this movement
  • top hole of the wind sleeve takes in the air stream and the sleeve swings. At the wind speed of at least 28 km/hour the sleeve inflates and indicates thus visually wind direction and speed
  • Wind Cone
    • it is made from the mixture cotton and synthetic material in accordance with the standard EN 10204-2.2
    • two colour executions
    • when inflated by air it gets shape of truncated cone
  • Construction of shell
    • it keeps the entry hole of the cone open even at absolute windlessness, it supports the cone and keeps it in the required shape at the distance of three eights of its total length
    • structure made of Al tubes is designed in such a way that it prevents accumulation of water in the cone
    • shell bearings are self-lubricating
  • Pole
    • tiltable structure with support enables easy replacement or maintenance of the cone, shell or bulbs of lighting and obstruction lights
    • top part of the pole contains revolving fitting enabling rotation of the shell with the cone
    • surface finish by powder plastic material  colour RAL 1021  (yellow)
  • Lighting
    • outside light reflectors assure that each point of the longitudinal axis of the sleeve top par in inflated state is lit by intensity of at least 10 cd
    • feeding is lead inside the supporting structure from the terminal box situated independently next to the basis
    • protected by fuses 6A situated in terminal box
    • pole can be completed by obstruction a low intensity light, which is mounted on the highest point of the pole and is not shielded from the top view by any other component of the wind indicator

twi schema enMechanical parameters

  • height (without illumination) 6 500 mm
  • height (with illumination) 6 750 mm
  • total weight ~90 kg
  • dimensions of wind sleeve (version heliport)
    • lenght 2,5 m
    • diameter 0,6 m
  • dimensions of wind sleeve (version airport)
    • lenght 3,75 m
    • diameter 0,9 m
  • resistance to wind to 140 km/hours
  • working temperature ±55 °C
  • cone excludes accumulation of water
  • minimum strength of fabric  667 N
  • indication of wind direction by turning of wind sleeve with accuracy of ±5° at wind speed of art least 6 km/hour
  • indication of wind speed (by inflating) at min. wind speed of 28 km/hour

Electrical parameters (illuminated variant)

  • protection IP 54
  • insulation resistance min 2 MΩtotal power input 700 VA (halogen)
  • total power input <120 VA ±10% (LED)
  • rated voltage 230 V / 50 Hz or 6,6 A airport series supply

Fixing to concrete foundation

  • two steel plates that are inter-connected by a steel pin enabling tilting of the pole
  • dimensions of the basis 300×300 mm
  • fixation to the concrete foundation by four bolts M 16 mm

Kvapilova 2133, CZ 738 01 Frýdek Místek
+420 558 437 551
+420 558 437 553

VATIN: CZ26510634
File number: C 86718
registered with Municipal court in Prague
Data box: i6v74tw