Deisel is now included, so if u have piston aeros with them fitted u have it............. i am going to put my foot in it here, but check awn 46 issue 23 if you still have it and read para 3, it refers to a licenced engineer needing to jump through some hoops to certify them, the current one issue 24, the whole para 3 has gone and everything has moved up to replace it, so there is now a different para 3
see
http://www.caa.co.uk/docs/33/CAP455.PDF