Magnetic anomaly detector

MAD rear boom on P-3C
The SH-60B Seahawk helicopter carries a yellow and red towed MAD array known as a "MAD bird", seen on the aft fuselage

A magnetic anomaly detector (MAD) is an instrument used to detect minute variations in the Earth's magnetic field.[1] The term refers specifically to magnetometers used by military forces to detect submarines (a mass of ferromagnetic material creates a detectable disturbance in the magnetic field); military MAD equipment is a descendant of geomagnetic survey or aeromagnetic survey instruments used to search for minerals by detecting their disturbance of the normal earth-field.

  1. ^ Wragg, David W. (1973). A Dictionary of Aviation (first ed.). Osprey. p. 183. ISBN 9780850451634.