Going DCT sometimes seems so much shorter, and also there sometimes are "holes" in the airway network that would need to be bridged by going DCT from one airway to another. Is that common in real life?

Very common, in fact in some areas such as the northeast corridor were a good majority of the jet airways tend to flow east west and vice versa you encounter this often.It also depends on time of day and your altitude as well.One particular evening I departed Atlanta around 1AM for Burbank-Glendale, we flew WETWO direct MEM.Fort Worth Center cleared us direct to IRW, Albuquerque Center cleared us direct ABQ then PMD and then LA Center gave us our arrival into Burbank. The G-V is certified for FL510, which we filed for and were given. At that altitude were not in much traffic in fact the only thing we encountered that evening was some guy using a military

Thanks for that enlightening response! Really learned smthg:) Just one more question on that: would you also FILE (and, consequently, do your fuel planning) a flightplan with many directs? For instance, would GEFAR B244 OTZ FYU NCA28 YOWbe a realistic plan, given that there is a DCT of more than 400nm between OTZ and FYU? (never mind the sample waypoints/airways I put here, I was just curious about having filed a plan that includes a DCT bridging two airways)Or are DCT only given by ATC once you are inflight?

You can plan and file any route you like regardless of the number of

Thanks a lot for that great tutorial!:-)