Mount Kelut (Indonesia) erupted explosively around 15:50 UT on 13 February 2014 sending ash and gases into the stratosphere. Satellite ash retrievals and dispersion transport modeling are combined within an inversion framework to estimate the volcanic ash source term and to study ash transport. The estimated source term suggests that most of the ash was injected to altitudes of 16–17 km, in agreement with space‐based lidar data. Modeled ash concentrations along the flight track of a commercial aircraft that encountered the ash cloud indicate that it flew under the main ash cloud and encountered maximum ash concentrations of 9 ± 3 mg m−3, mean concentrations of 2 ± 1 mg m−3over a period of 10–11 min of the flight, giving a dosage of 1.2 ± 0.3 g s m−3. Satellite data could not be used directly to observe the ash cloud encountered by the aircraft, whereas inverse modeling revealed its presence. Key Points Combining satellite retrievals and modeling gives valuable information Volcanic ash source term is constrained by satellite observations Estimates of modeled ash concentrations encountered by a commercial aircraft