The total length of natural gas pipelines in Germany exceeds 350,000 km. Currently, inspections are performed using hand-held sensors such as flame ionization detectors. Moreover, transmission pipelines are inspected visually from helicopters. In this work, remote detection of methane by passive Fourier-transform infrared (FTIR) spectrometry for pipeline surveillance is investigated. The study focuses on fast measurements in order to enable methane detection from a helicopter during regular inspection flights. Two remote sensing systems are used for the detection of methane: a scanning infrared gas imaging system (SIGIS), which was originally developed for the visualization of pollutant clouds, and a new compact passive scanning remote sensing system. In order to achieve a high spectral rate, which is required due to the movement of the helicopter, measurements are performed at low spectral resolutions. This results in overlapping signatures of methane and other constituents of the atmosphere in the measured spectrum. The spectra are analyzed by a detection algorithm, which includes simultaneous least squares fitting of reference spectra of methane and other atmospheric species. The results of field measurements show that passive remote sensing by FTIR spectrometry is a feasible method for the remote detection of methane.