CASA Windsock Requirements
In Australia, CASA (Civil Aviation Safety Authority) is the government body that regulates Australian aviation safety. They licence pilots, register aircraft and oversee safety. Here's what you need to know about Windsock compliance at aerodromes.
Topic
CASA Aerodrome Compliance
Key Standard
MOS Part 139 — Chapter 8, Division 7
Applies To
Certified & Uncertified Aerodromes
Sector
Aviation
Regulatory Background
CASA enforces the Civil Aviation Act 1988 (CAA) to ensure the safety of civil aviation, with emphasis on preventing aviation accidents and incidents. Forming the basis of the CAA are the Civil Aviation Safety Regulations 1998 (CASRs), which contain the Manual of Standards (MOS) and Advisory Circulars (AC).
As far as Windsocks (also referred to as Wind Direction Indicators) at certified aerodromes are concerned, the following CASRs are relevant:
Relevant CASR References
✓ AC 139.C-09 v1.0 – Visual Aids, Markings, Signals and Signs
CASR Specifications
Reference should be made to the full text of the CASRs, a summary (ONLY) of which is set out below:
| Requirement | Details |
|---|---|
| Minimum Installation | there must be installed and maintained at least one Wind Direction Indicator (Windsock). In some situations CASA may give orders that more than one wind direction indicator be installed; |
| Position and Height | The position of the Wind Direction Indicator (Windsock) is set out in the CASRs. The Wind Direction Indicator (Windsock) shall be as close as possible to being 6.5m above the ground; |
| Dimensions | The Wind Direction Indicator (Windsock) shall be 3650mm long, 900mm Ø mouth diameter, and 250mm Ø tail diameter; |
| Mounting Requirements | The mouth must be mounted on a rigid frame that: (a) keeps the end of the sleeve open; and, (b) keeps the sleeve attached to the pole; and, (c) allows the sleeve to move freely through 360 degrees around the pole; |
| Preferred Colour | The preferred colour for the Wind Direction Indicator (Windsock) shall be white; |
| Ground Markings | At a non-controlled aerodrome, the pole of at least 1 Wind Direction Indicator (Windsock) must be located in the centre of a 15m diameter circle, coloured black, and bordered by a white perimeter or white markers; |
| Additional Indicators | At aerodromes with more than one Wind Direction Indicator (Windsock), any additional Wind Direction Indicator (Windsock) must comply with Division 7 except that the sleeve colour may be yellow or orange; |
| Night Illumination | an aerodrome intended for night use at least 1 Wind Direction Indicator (Windsock) shall be lit in accordance with Chapter 9, Division 5. |
Important Note
The full requirements of the CASRs should always be referred to. The above is a summary only and does not replace official CASA documentation.
Key Requirements at a Glance
Uncertified Aerodromes
At an uncertified aerodrome, it is an operator’s and/or the pilots responsibility to determine suitability of the facility for use, in addition to the procedures to be followed. Refer to Aerodrome categories.
Further guidance is set out in AC 91-02 Guidelines for aeroplanes with MTOW not exceeding 5700kg – suitable places to take off and land.
Chapter 8.3 explains that the Windsock has been used for many years to provide pilots with wind direction and strength and sets out further interpretative information. It further explains that conditions that cause the Windsock to vary rapidly in direction, or where two Windsocks are available – a difference in direction or speed between the two is observed, these conditions should be treated with caution.
Your Compliance Partner
Windsocks Australia has been supplying Windsocks, poles, frames and illuminated Windsocks, to the Aviation Industry in Australia (and throughout Asia Pacific) for 20+ years, enabling pilots and operators to comply with CASA Standards. Please contact us for more information.
For further advice Contact Us. Click to take a look at our Product Range.
What We Supply
✓ CASA-compliant Windsocks for certified aerodromes
✓ Illuminated Windsock systems for night operations
✓ 20+ years serving Australian and Asia Pacific aviation
Key Takeaways
3650mm
Required sleeve length
900mm
Mouth Diameter
6.5m
Height above ground
360°
Free rotation required
MOS 139
Key standard reference
White
Preferred sleeve colour
Why Windsocks Australia?
- Australian Made & Owned — specialist manufacturer
- CASA, marine & hazardous area compliant range
- Premium fabrics — Sunbrella, WeatherMax & High Visibility Neon
- Stainless Steel hardware for harsh environments
- Proven track record across all major industries
About Windsocks Australia
Australia's leading manufacturer of industrial Windsock systems. Designed, engineered and assembled in Australia for the harshest environments — from offshore platforms to remote mining and LNG facilities.
windsocksaustralia.com.au | info@windsocksaustralia.com.au | +61 468 474 656
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