It is LED airfield guidance sign is the latest model of airfield sign to be manufactured by Vardhman airports. This sign is specifically designed to meet the ICAO requirements for Mandatory and Information airfield guidance signs. (ICAO Annex 14, Vol.I, Paragraph 5.4 and Appendix 4.)
Information signs are signified by yellow characters on a black background (location signs) or black characters on a yellow background (destination signs) and are used to provide additional guidance to pilots manoeuvring aircraft on the ground.
Mandatory signs are characterised by white characters on a red background and are used to advise pilots (and vehicle drivers) of an airfield location beyond which they must not proceed unless authorised by air traffic control.
The enclosure of the guidance sign is manufactured from a corrosive resistant aluminium extrusion which is powder coated, white as standard. Other colors are available Black / yellow, by special order. The guidance sign housing can be either single sided, only one message displayed or double-sided allowing for two messages to be shown in a bidirectional format. Both types of signs are designed to have a minimum ingress value of IP55.
Luminance / Chromaticity
This LED airfield guidance sign is designed specifically to comply with the ICAO specifications for color and luminance.
The legend panel is one single piece of substrate material that will cover all signs up to a maximum of 3m. To prevent damage to the message from external debris, such as stone chips created by jet blast, the inscription is applied on the inner face of the substrate material. The legend and fascia are UV resistant and flame retardant.
The airfield guidance signs IR858I, are powered from a standard 6.6Amp AGL circuit through a suitably sized isolating transformer. The design of the power supply units allows for the signs to be powered from different types of CCR’s that can be found in airports around the world. The thyristor type CCR comparable to the Micro 100, or an IGBT / ferro resonant CCR which has a sinewave output similar to that of the Micro 200 regulator can be used.
As the circuit input current varies the output brilliancy of the sign will vary relative to the input current. The output luminance will not fall below 1/3rd its average minimum value (at 6.6A) at the lowest input step (2.8A).
Other power sources include 230/110volt upon special request.
A rotary switch option is available which can be used to isolate the secondary current within the sign enclosure to enable safe maintenance work to be conducted. When the switch is activated a shorting link is also applied to the isolation transformer secondary. It is recommended however, that the primary circuit be isolated when working on AGL equipment.
Bird Deterrent System
Spike strips can be provided to help prevent birds from landing on the sign which helps to detract birds from resting in critical areas and also assisting in eliminating possible damage. Bird wire can also be offered as an alternative.
Stainless steel tethers are available to ensure that in the case of an incident the sign does not become a further FOD hazard.