off the beam

off the beam  {adv.} or  {adj. phr.}
1. (Of an airplane) Not in the radio beam that marks the path to follow between airports; flying in the wrong direction.
A radio signal tells the pilot of an airplane when his plane is off the beam.
2.  {slang}
Wrong; mistaken.
Maud was off the beam when she said that the girls didn't like her.
Contrast: ON THE BEAM.
Categories: {adj. phr.} {adv.} {slang}