I have over 3000 hours on the Alouette 111 with the Artouste 111B engine also includes the Lama and about 250 hours with the Astazou. The Artouste engine was very reliable although thirsty, 200 litres per hour while the Astazou was around 160 litres I believe. We operated from sea level up to the top of Damavand a 19,000 ft extinct volcano, and from below 0C degrees to +50C degrees.
Much of the work was sling often above 10,000 ft, also offshore from Sirri Island, Kharg Island, Lavan etc. The longest distance regularly flown was Bushere - Scan Bay - Bahrain and back something like 400 miles round trip. Never thought about the fact that it was single engine, so confident were we, or was it just the spirit of youth?
Our Alouette fleet flew around 2500 hours per month and in the five years I was there I only know of two engine failures. Neither resulted in any damage and in fact one was was restarted on the ground and flown back to base. They would also burn just about anything you put in the tank from jet fuel, diesel (used in remote areas where no jet fuel was available or in limited supplies) made a little smoke though and temperature limited in the winter. Petrol also, but was limited to 20 hours in the lifetime of the engine.
I found the Alouette good to fly, you could throw it all over the place, superb in the mountains, lots of power and easy to maintain. A pilot and engineer could go off into the bush for six weeks, fly up to 150 hours and all that was needed was routine daily maintenance.
Occasionally the engine did not want to start but the use of a little piece of locking wire to create a shunt, or re-positioning the T5-A relay switch would overcome the reluctance.
The question was which was the better helicopter the 316 or the 319. For myself it was the 316, it was a robust but thirsty engine and I had total confidence in it. The 319 was more economical but I never flew it long enough to feel as comfortable as in the 316 but that is not to say it was not as reliable.
Did I enjoy the Alouette 111, you better believe it.