Can you use a Q-route below FL180?
Posted by Max
on May 21, 2009
Category : Flight Instructor Blog
Max Trescott - 2008 National CFI of the Year
David asked the following:
“Hi, I have a question about Q-routes. I understand they were developed for class A airspace. However, the Q100 airway out of Tampa, Florida has a 6000 foot MEA and a 1500 foot MOCA. Can you use this airway assuming you have /G and say fly at 7000 feet on an IFR flight plan?”
Great question David. So great that it took some research and phone calls to the FAA! As background for readers, Q-routes and T-routes are relatively new types of airways defined by GPS waypoints and requiring an IFR-capable receiver. They were created to handle the increasing density of air traffic and to take advantage of the widespread availability of GPS. T-routes are low altitude airways and Q-routes are high altitude airways. Per the AIM, Q-routes can be flown as low as FL180.
Q100 appears on a low altitude en route chart, which normally is used only for navigating below 18,000. So that begs the question: Why does a
Q-route, which can only be used above FL180, appear on a low altitude chart which is only used for navigating below FL180? I didn’t know, so I called the experts, the FAA’s RNAV/RNP group. They thought it was a very good question too. Which is why they had to make 3 phone calls to find out–and they’re the experts!
The answer back was No, you probably cannot get a clearance to fly this route even if you filed for it, unless you were flying above FL180. The reason it appears on the chart–at least for now–is that it was one of the first GPS airways, and it was created before the altitude rules were established (in 2003 as I recall) for T- and Q-routes. Thus it’s a legacy, which doesn’t really belong on the chart. But now that you’ve asked us and we’ve asked the FAA, don’t be surprised if it disappears from future charts. So save your current chart. It may become a collectors’ item!