Simple FIR filter won't do the job, noise from the rotors and moving air is wideband and overlaps with signal.
But adaptive filters used in noise-cancelling headphones with separate mics may work. One directional microphone records sound from the scene, the other undirected one records sound of the drone, then filter tries to minimize drone sound component in the signal from the mic by adjusting coefficients of the filter.
But adaptive filters used in noise-cancelling headphones with separate mics may work. One directional microphone records sound from the scene, the other undirected one records sound of the drone, then filter tries to minimize drone sound component in the signal from the mic by adjusting coefficients of the filter.