Clutter

CLUTTER- In radar operations, clutter refers to the reception and visual display of radar returns caused by precipitation, chaff, terrain, numerous aircraft targets, or other phenomena.

GCR
Ground clutter rejection.
GEAR
Landing gear, the undercarriage and wheels of an aircraft.

Clutter is a dirty word.
7. Select the most experienced passenger to sit next to you.
8. Always begin an approach series with the one requiring the least effort.
9. Always depart with the return to field approaches most available.
10.

Much is made of noise canceling microphones and with good reason—the less background noise cluttering up your transmissions, the better.

It's no longer necessary for aircraft designers to create cluttered panel lay outs in order accommodate all necessary flight instruments.

Low-altitude flight also made the bombers very difficult to detect from aircraft at higher altitudes, including interceptors, as radar systems of that generation could not "look down" due to the clutter of the ground reflections.

See also: Aircraft, Altitude, Weather, Flight, Speed