How do you know that? And what does the color of their suits have to do with anything? (unless you mean the Men in Black either from the movie or part of a secret hush-hush military program, in which case we are departing the realm of the rational.) How do you know that? Are you referring to the apparent speed on the radar scope? Such speeds are common for transient return artifacts. Modern air traffic radars are programmed to reject such artifacts, since otherwise they'd clutter up the view of the controller. A quick blurb on this phenomena from Wiki: ========= Ringing artifacts pose a problem with search, detection, and ambiguity resolution in pulse-Doppler radar. Ringing is reduced in two ways. First, the shape of the transmit pulse is adjusted to smooth the leading edge and trailing edge so that RF power is increased and decreased without an abrupt change. This creates a transmit pulse with smooth ends instead of a square wave, which reduces ringing phenomenon that is otherwise associated with target reflection. Second, the shape of the receive pulse is adjusted using a window function that minimizes ringing that occurs any time pulses are applied to a filter. In a digital system, this adjusts the phase and/or amplitude of each sample before it is applied to the Fast Fourier Transform. The Dolph-Chebychev window is the most effective because it produces a flat processing floor with no ringing that would otherwise cause false alarms. ================== Do a little research before you say silly things like that!