IFR 22(b): Getting my Groove Back
Instructor R and I are back in the plane doing the “Cropper 1″ departure from our home airport. This is an unofficial procedure named after one of the other instructors that combines a departure from our home airport, a DME arc, and the VOR, ILS, and Localizer approaches. It is a well-designed local training procedure that we fly in VFR weather with foggles. We’re flying out and he says with a smile, “It’s another beautiful day and you get to look at your foggles. That’s ok, I’ll look outside for you!”
So I end up distracting myself by messing with the GPS and radio, I start the 10 DME arc at 9.6 nm or less. Not a great start, but within PTS tolerance. I turn the correct way, and track the arc. At the right radial we turn off to the VOR approach.
Things are going better, if not perfect. I’m at least with the plane, if not ahead. I’m missing smaller things, like the wind direction for the procedure turn to line up for the ILS. It takes a while to get back, as we’ve end up with a good headwind.
I’m not doing very well with radio calls that are useful for the other IFR and also for VFR pilots. R is pointing out after each call things I could have said better. His style is to let me do as much as I can, at this stage, that’s pretty much everything. He’s there to be my practice ATC (Air Traffic Control), keep an eye outside, and suggest better ways of doing things. This works for me.
On the way to the localizer, I “lose” my directional gyro as R puts a cover over it. I tell him, “I don’t get to see outside, and now I can’t see my pretty new DG either!” He smiles back and says, “Nope, but you’ve got a compass.”
Compasses have errors, well, so does everything. Aviation compasses in the northern hemisphere have a small weight on their south side to counteract the dip that the descending lines of magnetic force put on the compass. The inertia of this weight causes errors when accelerating or decelerating, more when heading E or W. No problems when heading N or S though.
When the plane is banked to turn, the weight falls down, and makes the heading undershoot when heading more N, and overshoot when heading more S. No problems on E or W headings though.
So there are two ways to make compass turns in IFR: by figuring the overshoot and undershoot (which is 1/2 your latitude in degrees). The second way is to measure the seconds in the turn. But I couldn’t remember if it was three degrees/second or three seconds/degree. It sounds silly now, but I couldn’t work it out and I didn’t want to ask R either.
At the time I was flying the plane, staying on altitude and heading, and responding to R’s simulated ATC radio calls.
I realized the turn coordinator had “2 min” on it’s face, so a standard rate turn for 360 degrees is two minutes, or 180 degress in 60 seconds. Ah ha! So, 180/60 = 3, so three degrees/second or about 3 seconds for 10 degrees. I was to turn 20 degrees, so a six-second count. I rolled out near my intended heading and was still on altitude.
So, I’m getting my groove back. I’m not where I want to be, but I’m within PTS now and that’s good.
I’m near the end, I still have the long cross country to do, and some more hours to build up. And I need to wrap up the written test too. But getting close!