Sometimes one's April Fool spoofs can go slightly wrong...
In 1984 I was the editor of Gateway and we printed an article on mods to the BAe 146 of the 146 Development Flight for 'special duties'. This included an AAR probe, and our cover showed it fitted to the aircraft and being checked by a technician. It was actually a convincingly painted broomstick with 2 support struts on top of the fuselage complete with a fairing made from layers of Dr White's sanitary products for ladies, which when sufficiently wetted made the whol thing looked very realistic indeed.
The article went on to describe 'a RFIL loop' fitted to the aircraft, which was supposed to deflect RF illuminating energy and also to apply polarising optics to 'reduce the optical signature' to make the aircraft invisible - it even concluded 'This is a specific property of optical fibres'.
No-one noticed either the anagram of 'April fool' or 'This is a s.. p.. o.. o.. f..' in the last sentence! Worse was to come, for 'Air Clues' swallowed it hook, line and sinker and also used the photo, referring to a 'technician adjusting the AAR equipment of the BAe 146P'. Eventually I had to phone the editor to tell him he'd been had - not a Happy Bunny!
But HALO from Concorde - did anyone really fall for that?