The 1-in-60 Rule

Since an airplane can fly in any of 360°, pilots have a rule of thumb to aid navigation that they call the 1-in-60 Rule.  This means that if you have a heading to follow in order to reach your destination and you are off by just 1°, then for every 60 miles that you travel, you will be about 1 mile away from your planned flight path.  Travelling over small distances means that it is relatively easy to course correct and back on track.  On average, it’s about 15-20 miles as the crow flies from the centre of London to the M25 orbital motorway.  Fly that distance and you’ll be about 1/4 to 1/3 of a mile off course.  Even on a rainy day, you’ll be able to see Heathrow Airport or the Dartford Bridge little difficulty and course-correct easily enough.  If, however, you take off from Heathrow and head towards Sydney, Australia, that one-degree difference could mean that you could arrive on the other side of Canberra, about 180 miles away!

Similarly, after years of bad habits and poor communication, the bond that makes a relationship so special starts to weaken.  Many distressed couples find that their connection has faded and many will start therapy describing their relationship to more like “flatmates” or “siblings.”  There often is no particular date on which they shifted from lovers to flatmates or partners to siblings.  Couples will often describe themselves as leading “parallel lives”.  However, those lines are not exactly parallel.  If you follow them backward in time long enough, they will converge on a single point and the default for most couples is to be just one or two degrees off by default.  The aim is to figure out what they need to do to bring those lines back to the same path.

I once explained this idea to a pilot and his partner.  He informed me that the maths are a bit more complicated than I make it seem, but once a pilot realises his or her error, it is necessary to calculate an overcorrection to get back on the right flight path.  In other words, it isn’t as simple as just adjusting your heading to what it should have been.  One also must make up for the distance travelled off course.  He astutely pointed out that both he and his partner were going to have to make some changes to how they interacted in order to make up for the negative interactions that they have had over the years.