On February 23, 2009, Rolls-Royce
indicated that a redesign of the FOHE was underway, and that
they anticipated the redesign to be tested, certified and
ready for installation within 12 months.
Just about the time it took to redesign, test fly and put into production a complete new Mk of Spitfire and several Merlin supercharger & carburrettor upgrades
....more than 60 years ago without CADM and with bombs dropping on one's offices and factories !