VOR
I bought a text book in order to prepare for the CVFR rating. I have always loved good text books. I know, that’s a bit weird, but I like to follow a well organized stream of thoughts on a specific topic.
CVFR is a very specific topic. Controlled Visual Flight Rule is a part of the qualifications of a private pilot. The rating will enable me to fly in controlled airspace and with guidance by ATC.
The big thing about CVFR however, is learning to make better use of the instruments and to use radio navigation.
VOR stations are the back bone of radio navigation. VOR is short for “VHF omnidirectional radio range”. The idea is very close to the idea of a light house. The VOR indicator in the cockpit shows me the bearing to the VOR station.
The VOR stations are marked on my aviation map. If I know That my relative bearing to the station is 090, I know that it is at 90° to the right. So I know that if I draw a line at 90° from the staion, my position would be somewhere on this line (called a radial, by the way).
This information alone is enough to get a pretty good idea about my position if combined with other VFR navigation skills (“this looks like the lake on the map”). At night or above the clouds however, I would need a second VOR station in order to do a triangulation. If I know that I am on radial 90° of station A and radial 200° of station B, I can draw two lines on my map and the point at which they meet is going to be my position.
Still with me? Great!
I have been taught to use the VOR from my first lesson for the private pilot on. My instructor knew that I was going to go for the CVFR rating eventually.
Today he means it. The flight preparation today is longer than usual. We have a very detailed flight plan. Up to the north and climbing up into the controlled air space over the city. Then a flight from the VOR in Löwenberg, via Tegel Airport to the VOR in Fürstenwalte. North to south over the big city.
I call ATC after take-off and anounce our big plan. After a bit they call back with bad news. The weather is bad, the airspace is full and they don’t need a green horn who needs extra attention. No clearance for me today.
Plan B is to clear the controlled airspace to the north and then climb to 7.500 feet and do our drills there. The day is rainy and other small aircraft ask for advice and divert right and left. My instructor is not impressed by a bit of rain on the screen and before long we are above the grey clouds. I close the vent as the stream of outside air is getting quite cold. The instructor hands me the IFR cap “Put this on”.
An IFR cap is a plastic visor that blocks the view to the outside. After I put it on, I can only see the instruments. What a difference!
Steady as she goes
The first task at hand is to hold course and altitude. The air up here is calm but I still need a lot of concentration for the task. After a bit, the instructor tells me to start going right and left, 10 degrees from the course. After this works, he pulls the flaps lever. Kilo Sierra slows down because of the added drag and climbs at the same time because of the increase in lift. I counter the movement and fight to keep the altitude.
Radio Navigation
The instructor seems to believe that I will not fall out of the sky. So we start with navigation. He tells me to fly to the Fürstenwalde VOR station. We had set the frequency before, so all I have to do now is turn the bearing indicator of the VOR receiver until the course deviation indicator is in the middle and the direction flag shows “To”.
The bearing to the station is 179, so I turn right onto the new course. After a few minutes, the instructor tells me to sink. We go down to 5.500 feet, 3.500 feet, then 2.000 feet. Finally I contact Strausberg and ask for QDM. That is the magnetic heading to the station. The controller on the tower can determine my relative bearing to him.
The heading to the airport is 250. So I turn right until I have 250 locked and ask again. 260 now. The runway is 270, so we are getting very close. The instructor tells me to sink to 1.000 feet and take off the cap. The runway is directly in front of me, I am on long final – wow!
After we are back on the ground and done with the de-briefing, I walk to the train station. There is a light drizzle and I enjoy the rain on my face. My head is pounding from the concentration, I’m exhausted but I feel great nontheless.
To be continued…
(originally posted on October 7, 2012 by tilbo at aloft.blog.com/vor/)