Flying IFR has its rewards. Certainty of clearances, routings, and ATC services eases workloads and provides reassurance. There’s no begging one’s way through busy or heavily regulated airspace under VFR, feeling like a trespasser. Now, direct routings enabled by GPS technology are becoming less the exception and more the rule.
That’s what performance-based navigation (PBN) is all about. “In the past, as pilots flew across the National Airspace System, they had little choice but to fly from one ground-based VOR transmitter to the next, often adding flying time and excess miles. No longer constrained by these devices, PBN enables aircraft to fly more directly from departure to arrival by using satellite signals. Closely spaced parallel routes and approaches become possible, and aircraft can descend to lower minimum heights over high terrain,” says the FAA’s website page explaining performance-based navigation’s role in a NextGen-modernized air traffic system.
So, what’s the catch?
Performance-based navigation’s routing flexibilities make it possible for IFR aircraft to transit some of the remaining areas of Class G that protrude above its usual ceilings.
Such routings bring procedural nuances that should be known before they play a role in an in-flight scenario that would have been better to avoid.
ATC will not deny a pilot’s request for routing through Class G airspace, but controllers won’t advise you when you enter or leave it. While you are in there, however, don’t expect IFR traffic separation services.
For example, ATC would not be responsible for keeping aircraft operating in IFR or VFR conditions separated. Yes, ATC would point out other aircraft, but if you are in cloud, that won’t help much.
Could you request a vector?
Perhaps. It would be considered additional service, and your aircraft must be above a minimum altitude. Meanwhile, responsibility for terrain clearance is yours.
Do such service limitations seem like a potential recipe for a complicated scenario?
“In the end, it is the pilot in command’s responsibility to be cognizant of what airspace the route will take them through,” said Rune Duke, AOPA director of government affairs for airspace and air traffic. "There is less and less Class G airspace above 1,200 feet agl, making it simpler, more efficient, and safer for the many aircraft conducting point-to-point IFR operations.”