The poor cockpit ergonomics of the bolt in British avionics suite and the unreliablity of the Nav kit in the beginning were not strong points, in fact the cause of a lot of accidents especially in the first 10 years until the FIN1064 kit was incorporated. After the GR1A mods, CFITs dropped but still occured. It was only the GR1B/GR3/A upgradres were GPS and TERPROM were incorporated that CFITs became a thing of the past, bar the last Jagaur frame loss in 2001 where the TERPROM database did not include Alaska. There were no other losses up to retirement. It was never a Marmite aeroplane, everyone that flew it, loved it.