Estimating Operations and AirportSpecific Landing Take-off Cycles at GA Airports—Estimating greenhouse gas and particulate emissions around airports is important when seeking to understand the impact on a community of existing or increasing aviation operations. Environmental consultants prepare models, and these models need estimates of the number of operations and landing/take-off (LTO) cycle characteristics. This information is difficult for GA airport managers to obtain. This presentation shows how to estimate LTO characteristics and the number of operations more easily by using sampling methods