Page:UK Traffic Signs Manual - Chapter 4 - Warning Signs. 2013.pdf/57



The low-flying aircraft sign, diagram 558, is for use on roads skirting or in the vicinity of airfields where road users are likely to be startled by low-flying 600 aircraft or by sudden noise from aircraft. A plate to diagram 558.2 indicating "Gliders" should be added where appropriate. A plate to diagram 773 (see para 21.3) should be mounted below the sign if wig-wag signals are installed to control the movement of traffic during the take-off or landing of aircraft.

The standard siting distances recommended in Appendix A are not likely to be appropriate for aircraft warning signs; an aeroplane might be virtually overhead before a driver sees the sign. It will therefore usually be more effective for this sign to be sited further in advance of the flight path, accompanied by a distance plate to diagram 570 (see section 18). However, in the case of wig-wag signals, signs to diagrams 558 and 773 should be sited at the standard distance from the stop line in addition to any general aircraft warning signs to diagram 558 used in advance. A distance may be added to diagram 558.2 where this is used; details can be found on the working drawing (see para 1.8).

Where helicopters are likely to be encountered, the sign to diagram 558.1 may be used. 56