I'mmmm let's see,
The ONCHO program has lasted for something like 20 years, and it basically about 2 things, one is applying chemicals in very precise doses into rivers of every size all over West Africa, the reason is control an insect that spreads Onchocercosis or "river blindness", and the other is "prospecting" which is going out and landing in rivers and villages to take samples and see if things are working OK.
We flew the MD500 D/E models, which does things that I didn't know helicopters could do, the maintenance is great, although they don't really worry about the appearance, and fancy stuff, bring your own GPS. At one time there was more than 30 500's working on the contract, and a couple of spray planes. We also had a Cessna 206 to go to the city, run errands.
There have always been 2 main bases one in Togo, LamaKara and one in Ivory Coast, Odienne, each one of those has its pros and cons and their share of very different flying, but the flying is almost always into neighboring countries, Guinea, Mali, Burkina Faso since it's where its most needed.
The flying . . . . ahh yes the flying indeed. Before I left, the Base Manager eMailed me and said "the flying is fun", I thought "flying is always been fun" . . . I was wrong.
We had a spray sistem thru which we applied small doses (say 1.3 lt) of expensive chemicals, this meant, being precise, being low so as to get it all in the water, and being most of all, FAST! The WHO is grouchy about pilots who take their time to make an approach to a river, this meant you could fly 150 miles or more in a day between or below trees, always trying to get as close to the ground, the water, as possible. When an WHO guy tells you to "make a drop" from crusing above the river, he expects you to inmediately dive for the river and get in and out of there as quickly as possibe and move on down the river. As you fly you get to see all kinds of cool scenery and animals.
There are fuel caches stewn about the country in small villages where you have to land and "recharge fluids" this is kind of a bummer since you have to do the refueling yoursef and those barrels are HEAVY! specially in 40C heat.
I had never refueled myself before I went there, and moving those barrels could always be exciting since 20cm scorpions and Cobra snakes liked them for shade.
You kept in strict contact with your base reporting every new river, TO or LDG, via HF, they always knew where you where which was great in case you inadvertanty ran into a tree, and had to have someone get you, it happened more than once. There are practically NO wires in any of the countries, only large cities have electricity and telephone so the few wires there are are clearly known. We usually went out on tuesdays, and came back, the next day or the day after that, spent the night mostly in small hotels in the other countries.
Overall it was a cool job, lot's of fun. The Con's were, flying in aircraft in which looked like they had belonged to the Taliban, dealing with the chemicals and fuel all the time, and that since the program is winding down after 20 years there are few people at the bases to make friends with, historically Evergreen has hired people from all over the world to do the job in, this makes it more intersting and fun, in our 2 bases, we had people from, Portugal, Switzerland, NewZeland, England, Peru, France, Mexico (me), and U.S.
Well here you go, hope this gives you a picture.