NEW YORK ( TheStreet) -- The eight-month-old Claymore/NYSE Arca Airline ETF ( FAA) was the best-performing exchange traded fund in the third quarter as airline companies loaded up planes with passengers over the summer.The Claymore/NYSE Arca Airline ETF returned 51%, beating the No. 2 Market Vectors Brazil Small-Cap ETF ( BRF) by 6 percentage points. (Leveraged funds were excluded from our review. The top leveraged fund was Direxion Daily Financial Bull 3X Shares ( FAS), which rocketed 78%. Two key metrics for the measurement of airline health are "available seat miles" and "revenue passenger miles." Available seat miles measures capacity by counting the number of seats available times the distance traveled. Revenue passenger miles multiplies paying passengers by the number of miles traveled. This allows the "load factor" percentage to be found by dividing revenue passenger miles by available seat miles. The U.S. airline industry's load factor climbed to more than 80% in July and August from a low of 70% in January. AirTran Airways ( AAI) set a new personal-best September load factor of 77% on an 11% increase in revenue passenger miles compared with 12 months earlier. Continental Airlines ( CAL) traffic gained 7% over the same period, and its load factor hit 81.5% on restricted seat capacity. Taken as a group, the airlines held by the Claymore/NYSE Arca Airline ETF are expected by analysts to see a smaller decline in revenue than in the prior quarter. This optimism combined with relatively quiet energy markets led to super-cruising third-quarter return velocities of 189% in UAL ( UAUA), 98% in AMR ( AMR), 63% in US Airways Group ( LCC), 86% in Continental and 55% in Delta Air Lines ( DAL). The Market Vectors Brazil Small-Cap ETF, started just over four months ago, is weighted toward 12% real estate, 10% homebuilders, 6.9% retail, 5.4% commercial services, 5.4% building materials and 5% telecommunications. If Rio wins the contest to host the 2016 Olympics, this fund is well-placed to score gold. Regardless, its fortune is tied to the rising standard of living in Brazil.