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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: aircraft magnetic compasses
From: Paul Hirose
Date: 2005 Feb 2, 23:19 -0800
From: Paul Hirose
Date: 2005 Feb 2, 23:19 -0800
George Huxtable wrote: > > Isn't it true that magnetic bearings also enter into the labelling of > runways? Correct. For example, a runway oriented to 60 degrees magnetic would normally be designated Runway 06 or Runway 24, depending on which direction is in use (normally determined by the wind). With two parallel runways at the airfield, they'd be called 06L and 06R, etc. I think letter C can be used too if there are three parallel runways. Los Angeles International has *four* parallel runways, so one pair's numbers are fudged a little to eliminate conflict: the runways are called 06L, 06R, 07L, and 07R (or the reciprocals). In reality, all four are parallel to better than .1 degree. I doubt that runway designations are changed if the magnetic variation changes at the airfield. The 10 degree numbering increments so coarse, the situation should rarely occur. If it does happen that a number change becomes appropriate from a mathematical standpoint, I'm sure the practical difficulties of repainting the runway numbers, revising publications, etc. would take precedence. For an instrument approach you do need accurate runway heading, but that's found in the published approach procedure.