Lan Chile are one of the smaller members of teh Oneworld alliance, and as you may guess, are the national airline of Chile.
Having experienced both their long haul and domestic services I have to say that they really are not bad at all.
There is a distinct difference between their international and internal services. On domestic routes the airline is a little more like a bus service, making multiple short hops, meaning that you may actually take longer to reach your destination than you may think. A short flight for example between Santiago and Ariquipa would take a little under an hour direct, but with up to three stops on the way this soon adds up to a two and a half hour flight. The service though is quite good. Even on these short hops you are treated to a drink and a light snack by courtious cabin crew who appear both professional and dedicated. If there were an advantage to the multi-hop method it would have to be that you are fed and watered on each leg, so you probably receive more than of you were on a 5 hour international flight.
The standard domestic aircraft is the boeing 737, and though all of the aircraft I have used were a little rough around the edges there was a huge amount of legroom and the seats were perfectly adequate.
The possible disadvantage of flying Lan chile on domestic routes, or routes within South America is the price. While they are not terribly expensive (my Santiago-Ariquipa flight was around US$120) they do have some serious low budget rivals. Aero Continente has risen through the ranks to be a serious contender within South America, and while there punctuality and service is apalling they do charge up to 60% less.
Where Lan Chile really excel is in the Long haul sector. It isn't often that people buy tickets for the airline direct. It is more likely that you would fly a sector as a One World partner, especially if you are flying some of the more unusual routes such as Australia / New Zealand to South America where few airlines fly. With free stopovers in places such as Tahiti and Easter Island (they are the only airline to fly to easter Island) you have the option to visit places you would otherwise never visit. Add to this the fact that their connections through to the USA and the rest of South America are excellent this makes the airline a serious contender for your business.
One of the great advantages of selecting Lan Chile is that in all of my flights with them I have never seen a full aircraft. With more legroom than on most long haul flights inflight comfort is notibly high. The inflight entertainment has yet to be upgraded to the seat back TV's, and this is a shame as this omission is almost the only factor preventing Lan Chile from competing with the very best of the rest.
Inflight catering is excellent, and while there is not a huge variety what there is is of a high standard and well presented. The crew are both courtious and professional and add to the whole experience by being very eager to cater for your every need.
All said and done there are better airlines out there, yet with some very unique routes and a better than average service Lan Chile are well worth considering. While in my opinion they remain the best South American airline, with an upgraded inflight entertainment system and perhaps a slightly improved domestic service they could become even better.