Even more silly, RAF Pumas were at one time fitted with rear view mirrors. It was just prior to the fitting of polyvalent (PIP) engine intakes. The “book” purpose was to monitor the intakes and the flat plate cowling area between them for any build up of ice/snow; the engines had no other ice protection and a small amount of slush going down an open Turmo intake could cause a flameout. This slightly extended the low temperature operational envelope. However, when the PIP intakes were fitted the mirrors were removed, much to our dismay. As far as I know, there had been absolutely no consultation with operational aircrew on their removal. On seeing that they were being taken away (and the rivets holding the brackets being drilled out) we asked to retain them because they could be repositioned to look all the way down the sides of the aircraft, which allowed the front seat occupants to view both the exhausts and the tail. The FRC engine fire warning drills required us to “Check for signs of fire” before taking further actions. Mirrors would have made this so easy.. how else would this be easily done if IMC?