I'm working in the vicinity of military airspace today, where by today I mean the day on which I took these cryptic notes and put them in my blogging file. In Canada the lateral boundaries of permanent military airspace are marked on charts with a busy line itself composed of fine parallel lines that are perpendicular to the line they define. The area so designated is usually tagged CYR and a unique three digit number. That must be C for Canadian, Y for why do Canadians use Y so much in aviation? and R for restricted. The number is so you can look it up in the Designated Airspace Handbook to see who is in charge of it. Some military airspace may be CYA (A for advisory), but that just warns pilots that military aircraft may be present, and doesn't obligate pilots to remain clear or obtain permission the way restricted airspace does.
The vertical and temporal limits of restricted airspace must be discerned by careful scrutiny of the notations inside the marked boundaries. A lot of military airspace is only active nine to five local time Monday through Friday. Given the non-business-hours nature of military operations, this always seems a bit strange to me, but it's nice to be able to use their sky on the weekends. The civilian term for airspace restrictions being in effect is the word I just used, active, but the military controllers say hot and cold which is short and clear and sounds flashy. The military are good at that. Often military airspace is hot between certain altitudes continuously and then at an extended range of altitudes occasionally by NOTAM. That means I have to check the NOTAMs to see if CYA 999 is active today, but of course I have to check the NOTAMs anyway to see if there are any temporary flight restrictions. And yeah, I used that phrasing so I could make fun of the US which has what appear to be permanent TFRs over strategic national locations such as Disney World. They do have some pretty advanced robotics there, and you never know, Disney World might close down before the end of the current chart cycle.
On the particular day I'm writing about, I have done the chart interpretation dance before the flight, and decided that our work doesn't require entrance to the military airspace. I talk to the military controller anyway, for flight following. I go under some airspace, because its floor is above the altitude I need. Some parts are NOTAMed cold, so I get to go through them. There are clouds in the area we want to work, but the actual spot we want to overfly is very small, so we fly around in circles waiting for the clouds to get out of the way, and trying to dodge them and their shadows well enough to complete the work. It takes a number of passes, but we get it all and then inform the military controller that we are going to land at a small non-military aerodrome nearby. There's a published mandatory route to land there, and I tune a particular radial to ensure I follow it. The controller sees what I'm doing and clears me direct. Well that was easy.
There's an elaborate honour system involving multiple codes and keys to obtain and pay for fuel here, and a really questionable restroom. A wave hello to those who know exactly where I am today. I know it can't be too hard to figure out if you've been here, and it's okay to guess in the comments if you want, but more fun for the game to leave cryptic hints than a straight out answer. Once everything is put away I file a new flight plan and depart. The controller again clears me direct through the airspace I planned around. Just in case you need confirmation of your guess where we are, my fellow crew member starts making cow noises after a pilot coming into the same airport reads back his clearance. I laugh hysterically, because I had been about to moo, too.
On the ground an older pilot sees my ride and comes up to me to reminisce because he once worked in Nepal flying the type I'm flying now. He nails the strengths and weaknesses straight off, and tells me something I didn't know, that the fuel selector is designed such that at low temperatures it can become impossible to switch from the inboard to the outboard wing tanks. Interesting. I had not known that. The manual permits take off and landing on any tanks, without a published restriction on which fuel is burned first, as long as there isn't a sizable imbalance between wings.