If you had access to Part 4 of the UK Mil AIP, you could look in there and see the true extent and effect of Oakhanger. In this document, it states that the hazard is only in the sector 090 TO 270 deg, in other words it's actually a semi circle NOT a full circle. In any case although it MIGHT affect on board electronic gizmo's, it was actually established when a Wessex fitted with radio triggered flotation bags flew through it and the bags inflated!