MarkXS

Also you would not be joining AviancaTaca Lifemiles - that makes no sense. What you want to do is use the miles of another Star Alliance Member, Singapore in this case, to book an award that includes flights on a different Star Alliance airline, Taca.

Joining LifeMiles has absolutely nothing to do with what you are attempting. Awards to fly on any of the *A airlines must come only from the award ticketing department of the *A airline in which you have miles.

Because AV/TA has a variety of award levels for its own members plus that sliding-scale miles+money, using LifeMiles.com to check AV/TA availability for what awards are published via the StarNet to the rest of Star Alliance is frustrating and confusing. Most of what you find on LifeMiles will not be available to United Mileage Plus or Lufthansa Miles & More or to Singapore FF members.

If the flight shows up on United.com as available for an award booking, it should be available for SQ (Singapore) to book it too. Or if it shows up on ANA's site (the "ANA tool" people often talk about on FT for checking *A availability.) ANA may have less of a bias against finding it, because United Mileage Plus is also the native program of Copa Airlines, based in the same region as AviancaTaca (Central American & Colombia). Thus the UA site tends to display Copa or mixed Copa/Taca itineraries, but can be talked into showing it if you put in the specific flight times and cities in a multi-city search.

The upside of using united.com for this is that ANA now I believe requires that you have some ANA miles to use their search. United doesn't even require that you be a MileagePlus member.

As to the cabin config: Taca (as opposed to Avianca) is an all-narrowbody airline. The front cabin is basically North American-style domestic First class configuration. All Airbus 320-family. So nowhere near International Business Class; however better than typical European airline narrowbody Business Class which is usually just coach seats with the middle seat blocked.

Taca uses an advanced Recaro coach seat that has no seatback pocket taking up knee-room and a sliding recline, so it has a lot better comfort for the measured pitch than you would expect. On every Taca Peru flight, which is the subsidiary you would be on for LIM-GRU, I have had seatback AVOD IFE and a USB charging port. So in business, my expectation for you would be a nice domestic F-type recliner seat with entertainment. Zero possibility of anything better than that. Some possibility of no AVOD/Power.

edit: BTW by the time you fly, Taca will be rebranded as Avianca, as the holding company's single brand for the combined Avianca (Avianca) and Grupo Taca (Taca International - El Salvador, LACSA - Costa Rica, and Taca Peru) operation. However only "real Avianca" has any widebodies and I think they only fly them TATL from Colombia, and maybe on some heavy-load US-Colombia routes. If you want LIM-GRU from Star Alliance partner miles on a widebody with a real business class, you need to be looking at LATAM Airline Group's TAM Airlines while TAM (JJ) is still in Star Alliance.

LIM-GRU isn't all that long a flight. I'd save miles and get Taca coach.