Customs pilots have gone to great lengths to try to keep the F-16s from
becoming involved, to the point of crafting handmade signs with the
emergency frequency on them and waving them at pilots of target aircraft
through the Citation's cockpit windows. Cox said that in the end, they
just painted the frequency on the noses of the Washington-based aircraft
so the customs pilots could better maintain visual contact (it was hard
to see through the signs).