SURFACE FRICTION
A durable, type-tested alternative to conventional painted surfaces
0.68
TESTED FRICTION COEFFICIENT
NLR
LABORATORY TESTED
Zero
RECURRING FRICTION TESTS
Zero
BLASTING OR PAINTING
WHY THIS EXISTS
Adequate surface friction is essential for safe helicopter operations, particularly during wet or challenging offshore conditions. Traditionally, helidecks rely on abrasive blasting and anti-slip coating systems to achieve the required friction levels. Over time, these coatings can deteriorate and require periodic inspection, maintenance and friction retesting.
AOPL offers a much better solution: a mill-finished aluminium surface, engineered to provide permanent friction performance without the need for background painting or abrasive blasting.
Background painting is not required for aluminium helidecks. CAP 437, paragraph 4.8, recognises that the natural light-grey colour of untreated aluminium is acceptable, provided that the essential helideck markings remain sufficiently conspicuous. Where additional visual contrast is required, individual markings may be enhanced without applying a painted background across the entire helideck surface.
WHAT IT DELIVERS
Permanent friction profile incorporated into the deck surface · Tested friction coefficient of 0.68 · Meets the requirements for both fixed and moving helidecks
Laboratory tested by the Netherlands Aerospace Centre (NLR) · No recurring in-service friction testing required under the type approval
No background painting required · No abrasive blasting required · No deterioration of an anti-slip background coating
Reduced inspection and maintenance requirements · Lower whole-life maintenance costs
AGAINST PAINTED SURFACES
Conventional painted or blasted helideck surfaces normally require periodic friction testing. Under UK CAA CAP 437 guidance, testing is generally carried out annually, although the interval may be extended to two years where the measured friction values sufficiently exceed the specified minimum requirements.
Painted surfaces may also require periodic preparation and recoating due to wear, weather exposure and operational use.
By comparison, the AOPL permanent friction surface has undergone full-scale type testing as a profiled helideck surface. Under the applicable type-approval provisions, no further routine in-service friction monitoring or testing is required, provided that the approved surface remains unmodified and in serviceable condition.
COMPLIANCE
The AOPL Permanent Friction surface has been developed with reference to the friction criteria established in UK CAA CAP 437 and ICAO Doc 9261. The applicable guidance identifies the following minimum surface friction coefficients:
Fixed helideck
Moving helideck
Inside the TD/PM circle
0.60
0.65
TD/PM circle and H painted markings
0.60
0.65
Outside the TD/PM circle and parking areas
0.50
0.50
IMPORTANT
To preserve its approved friction characteristics, the Permanent Friction surface must not be abrasively blasted or covered with a background coating. Any unauthorised surface treatment may alter the engineered profile and invalidate its type-approved status.
Only the required helideck identification and operational markings should be applied in accordance with the approved specification. In line with CAP 437, visual contrast may be enhanced where necessary, for example by placing white markings on a localised black background or outlining the yellow TD/PM circle in a thin black line, typically 10 cm wide.
The AOPL Permanent Friction surface provides reliable friction performance without relying on a maintenance-intensive anti-slip background coating. It offers helideck owners and operators a durable, lower-maintenance solution designed to retain its functional characteristics throughout the service life of the helideck.
Enquiries
Tell us about the deck and the friction requirements that apply, and we will advise whether the permanent friction surface suits your operation.
