14.27 What does "J168" mean - and what's a GPS?
From FlightSim
A J### is a US high altitude (18,000-60,000) airway called a Jet Route. It is a defined route between a series of VOR's and intersections. For example, if you wanted to fly from Dallas-Fort Worth to Nashville you could fly along J42 which is DFW-TXK-MEM-BNA. Below 18,000 feet the airways are called Victor Airways and are numbered V###.
GPS stands for Global Positioning System, which is becoming the new standard in naviagation. It uses satellites to triangulate your position in three dimensions with an accuracy of less than 100 meters. GPS is nice because it allows you to fly a direct course between two places rather than zigzagging between VOR's.
MDK
J168 is Jet airway number 168 -- part of the high altitude airway structure.
You need NOAA or Jeppesen high altitude en-route charts to see these. There are
also Victor (VOR) airways in the low altitude en-route structure (below 18,000
feet), which can be found on the low altitude en-route charts (both NOAA and
Jeppesen) and also on sectional charts for VFR use.
These airways are all defined by specific radials from various VORs (radio navigation stations).
GPS stands for Global Positioning System, a constellation of 24 satellites (21 active at a time), which transmit continuous signals. When 3 or more of these satellite signals are received by a GPS receiver, you can read out your current location (among other things) on the GPS display. With at least a fourth satellite added, you can also get an altitude readout, although I'd not trust it to be closer than 700-1000 feet to your actual altitude with a NORMAL GPS signal (yes, I've seen errors in altitude that great; also I've seen it within 100 ft).
Larry N.
