Helipad Windsock Requirements: Hospital, Offshore and Private Helipads

Helipads are unforgiving environments. A pilot approaching a rooftop hospital deck, an offshore platform in the North Sea, or a private estate pad has seconds to read wind direction and speed before committing to the final approach. The windsock is the primary visual wind indicator on every one of those decks, and its specification is not a matter of preference. It is written into CAA CAP 168, ICAO Annex 14, and the sector-specific rules that sit above them.

This guide sets out what UK procurement teams, aerodrome operators, hospital estates managers and offshore duty holders need to specify when sourcing a helipad windsock. It covers dimensions, visibility, illumination, mounting, and the differences between onshore hospital sites, offshore installations, and private landing areas.

Why the helipad windsock is a regulated item, not a fitting

A helipad windsock is classed as a visual aid to navigation. In the UK, the Civil Aviation Authority CAP 168 (Licensing of Aerodromes) and CAP 437 (Standards for Offshore Helicopter Landing Areas) set the baseline. Internationally, ICAO Annex 14 Volume II covers heliports specifically. Where hospital helipads operate under HTM 06-06 guidance, the windsock still has to meet aviation visibility and illumination rules.

The consequence is straightforward. A windsock that fails inspection can ground the pad. For a hospital HEMS deck or an offshore production platform, that is not a maintenance issue. It is an operational risk.

For a wider view of standards, see our guide on windsock compliance standards.

Baseline specification for a helipad windsock

The windsock must be a truncated cone, visible from the air, and free to rotate through 360 degrees. It must respond to winds of 3 knots (about 1.5 m/s) and indicate wind speeds up to at least 15 knots by fully extending horizontally.

Colours are prescribed. A single high-visibility colour (international orange) is standard for helipads under CAP 168 and ICAO Annex 14. Where the background is likely to reduce contrast, alternating orange and white bands of equal width are permitted. Five bands is the common configuration.

Dimensions by helipad type

Helipad type	Minimum sleeve length	Throat diameter	Mouth diameter	Governing standard
Hospital rooftop (HEMS)	2.4 m (approx 8 ft)	0.6 m	0.9 m	CAA CAP 168, HTM 06-06
Offshore installation	2.4 m minimum	0.6 m	0.9 m	CAA CAP 437
Private onshore pad	1.2 m minimum, 2.4 m preferred	0.3 to 0.6 m	0.45 to 0.9 m	CAP 168 Chapter 6
Licensed heliport	2.4 m	0.6 m	0.9 m	ICAO Annex 14 Vol II
Elevated FATO	2.4 m	0.6 m	0.9 m	EASA EU Regulation 139/2014

The 12 ft (3.6 m) size is common on larger commercial heliports and offshore decks where sightlines are longer. For most UK hospital and private pads the 7 ft (2.4 m) or 8 ft variant is correct. Our windsock size guide gives the full breakdown.

Hospital helipad windsock requirements

Hospital HEMS pads in the UK sit under CAA CAP 168 for licensed sites and under HTM 06-06 for NHS estates planning. The windsock has to be visible from every approach and departure path, which for a rooftop deck usually means a single mast positioned to avoid conflict with the FATO (Final Approach and Take-Off area) and TLOF (Touchdown and Lift-Off area).

Key points for hospital procurement:

• Illumination is mandatory for any pad used at night or in low visibility. That means either internal LED illumination or external floodlighting that reaches the full length of the sleeve.
• The mast must not infringe the obstacle limitation surfaces. This is where fixed masts fail. A swivel-arm or hinged pole allows the windsock to be lowered for replacement without a MEWP or working at height permit under LOLER 1998 or BS 7121.
• Replacement cycles matter. UV exposure and city pollution degrade fabric. Most hospital sites replace annually. See our windsock replacement guide for the inspection intervals.
• The colour scheme on hospital pads is almost always solid international orange. This maximises contrast against both sky and urban backgrounds.

For rooftop installations, the Falcon Swivel Arm (/products/falcon-swivel-arm) is designed to lower the windsock horizontally, keeping maintenance at deck level.

Offshore helipad windsock requirements

Offshore is the harshest environment a windsock will see. CAP 437 sets the standard for UK continental shelf installations and normally requires:

• A 2.4 m minimum sleeve length
• Two windsocks on larger installations, one visible from each approach sector
• Full internal illumination, powered from the platform emergency supply
• Salt-spray resistant mast, bearing and swivel assembly
• Fabric rated for sustained winds well above the 15 knot indication threshold, typically to 90 knots survival

Offshore duty holders operating under HSE COMAH will want to align windsock procurement with the wider safety case. The mast, bearing and fixings are lifting-adjacent equipment and should be inspected under LOLER 1998 alongside other deck fittings. Where the windsock is accessed via a fixed ladder or fall arrest system, BS EN 1808 (for suspended access) or the site's own working at height plan applies.

The Falcon Heavy Duty is the specification we recommend for offshore duty. Full COMAH compliance verification for the Heavy Duty is in progress and we will publish the certification when complete.

Private helipad windsock requirements

Private helipads (estate landing sites, corporate pads, agricultural strips used for rotary) sit under a lighter regulatory regime, but the windsock still needs to be legible from the air. CAP 168 Chapter 6 sets the visual aid standard. Practically:

• A 7 ft (2.4 m) windsock is the sensible default. A 4 ft is only adequate on very small, low-traffic pads.
• Solid orange for maximum visibility.
• Free-rotating bearing that responds to 3 knot winds.
• A mast tall enough that the windsock is not screened by trees, buildings or the helicopter itself on approach.
• Illumination if the pad is ever used after last light.

Most private pads do not need duplicate windsocks. One correctly positioned unit is enough. See our windsock installation guide for mast height and siting.

Snap-on versus lace-on for helipad use

The two attachment methods each have a place on helipads.

Snap-on windsocks fit a sprung frame and can be replaced in minutes. This is the preferred choice for hospital and private pads where maintenance windows are short and estates teams manage the change themselves.

Lace-on windsocks bind to the frame with a continuous lacing cord. They are more robust in sustained high winds and are the standard choice for offshore and exposed coastal pads.

For a fuller comparison including durability data, see aviation vs industrial windsocks.

Illumination and night operations

Any helipad approved for night use requires an illuminated windsock. There are two accepted methods under CAP 168 and ICAO Annex 14:

1. Internal illumination using LED strips inside the frame, powered by low-voltage DC. This is the modern default. It gives even light along the sleeve and avoids external glare.
2. External floodlighting directed onto the sleeve. Acceptable if the light is white, evenly distributed, and does not dazzle approaching pilots.

For offshore installations, the illumination circuit should be on the emergency bus. For hospital pads, it should be on the essential circuit that covers the pad lighting and perimeter markers.

Mounting, mast height and inspection

Helipad windsock masts are typically 3 to 6 metres above the deck surface, positioned so the windsock itself is above the tallest obstacle within a 15 metre radius. For rooftop pads the mast is usually shorter because the deck itself is elevated.

Inspection cycles we recommend:

• Weekly visual check by the pad operator
• Monthly close inspection of the sleeve, frame and bearing
• Annual replacement of the sleeve on any pad in regular use
• Annual LOLER inspection of the mast and any lowering mechanism where it is classed as lifting equipment

Frequently asked questions

What size windsock is required on a UK hospital helipad?

A 2.4 m (approximately 8 ft) sleeve is the standard specification under CAA CAP 168 and referenced in HTM 06-06 for NHS HEMS pads. Smaller sizes are not adequate for hospital rooftop use.

Does a private helipad in the UK need an illuminated windsock?

Only if the pad is used at night or in low visibility conditions. For daylight-only private pads, an unlit international orange windsock meeting CAP 168 Chapter 6 dimensions is sufficient.

How often should a helipad windsock be replaced?

Annual replacement is standard practice for helipads in regular use. Offshore and coastal pads may need six-monthly replacement due to UV, salt and wind loading. Any tear, fade or bearing stiffness is grounds for immediate replacement.

Are two windsocks required on offshore helidecks?

CAP 437 requires visibility of a windsock from every approach sector. On larger installations this typically means two windsocks positioned on opposite sides of the deck. The operator's approved helideck documentation confirms the exact requirement.

What colour should a helipad windsock be?

Solid international orange is the default under CAA CAP 168 and ICAO Annex 14. Alternating orange and white bands (usually five bands) are permitted where background contrast is poor.

Can a helipad windsock be lowered for maintenance without working at height?

Yes, with a swivel-arm or hinged mast. This is the recommended arrangement for hospital rooftop pads and any site where working at height under LOLER 1998 or BS 7121 would otherwise be required for a simple sleeve change.

Do offshore helipad windsocks need to meet COMAH?

Offshore helidecks sit under HSE COMAH where the wider installation is a COMAH site. The windsock forms part of the safety case. Falcon Heavy Duty COMAH compliance is being verified separately and documentation will be published on completion.

About the Falcon Premium range

The Falcon Premium is our aviation-standard windsock, manufactured in the UK to meet CAA CAP 168, ICAO Annex 14 and FAA AC 150/5345-27F. It is available in 4 ft, 7 ft and 12 ft sleeve lengths, in snap-on or lace-on attachment, in solid international orange or alternating orange and white bands. Every Falcon Premium ships worldwide with free delivery and all duties and import taxes covered (DDP), so the price you see is the price you pay to your loading bay.

For your next helipad procurement, review the Falcon Premium Snap-On for quick-change installations, the Falcon Premium Lace-On for high-wind exposure, and the Falcon Swivel Arm where lowered maintenance access is needed. Speak to our compliance team for a specification review against your pad's approval documentation.