Well, everytime I look in the back of an RAAus mag theres at least one - if not two or three - incidents involving a Jabiru powered craft either neccessitating a shut down or suffering mechanical failure of some sort. I reckon the poor old Jabiru design is either suffering 'tall poppy' syndrome via market saturation or the design is being overstressed.
The internal combustion engine may well be somewhat 'off the mark' as far as perfection goes, but then again it is easily constructed, maintained and operated. I say thats a pretty good deal. As for environments that weren't anticipated... thats crap. All air designers know that engines may well be used anywhere in the world and under almost any condition - thats the precise nature of aircraft.
The Merlin engines were reliable in Lancasters because they were detuned and subjected to much kinder operating conditions. They were somewhat cantankerous in Spitfires because of their greatly increased state of tune, and the fact that they were operating on, what was then, the edge of the possible. I would also say that the wartime demand had stressed the production facilities and maintenance to the point of impacting on reliability, too.
An EGT is almost a neccessity in an aircraft and I would be somewhat uncomfortable without one as they can show up engine problems as they start and before they become a dangerous emergency situation. They also show good engine tuning, running condition and are cheap and easy to install. 'Hot and hard' may well sound a bit harsh but you need reasonable operating temps and efficienct combustion (ie hot and hard) to run an engine at its best. THis also happens to prevent carbon buildup, sticking rings, etc.
No mixture control? Either its EFI or something is seriously wrong.
Light aircraft are, like anything, quite safe when operated and maintained correctly. I could, for example, be out flying my Minicab at the moment as its a gorgeous day here in Goulburn. However, I am of the sorts not to want to fly on a tyre going bald, nor a prop that is structurally ok but also over 42 years and 900 hours old!
The way I see it is that if people take risks, they accure a 'luck debt'. Like all major owings, sooner or later the debt collector comes around. In aviation, he wears a dark hooded robe and carries a scythe.
CHeers - boingk