Complex sentence: In 1951, Lockheed was approached by Capital Airlines to develop a new turboprop airliner designated the YC-130, however there was no interest from other American carriers, so the design was dropped.
Split into simpler sentences: In 1951, Lockheed was approached by Capital Airlines to develop a new turboprop airliner which was designated the YC-130. There was however no interest from any other American carriers, so the design was dropped.