Jan 23 2007

Flying Holds using Autopilot in a Cirrus...

Category: Personal Flights | Training ThoughtsMJG @ 21:51

I guess I've kind of fallen behind in my blogging about personal flying. I've actually, with the kinds support of my wife, gotten back on my instrument training.

I had stopped after the first third of the training about two and a half years ago to concentrate on transitioning into the Cirrus. And like many others, it has been a challenge to get back to this point due to work, family and just life in general.

I've been flying with Ron from Sunrise and he's great. Lots of experience in SR22s as well as many other types of airplanes. We went up Monday night for some practice and after doing a number of maneuvers, we moved on to try a few holds using the autopilot.

It actually was much simpler than I thought it would be. Of course, we were holding over a VOR so it was much simpler than it would be at an intersection but here's the drill.

Avidyne PFD Once you've copied and acknowledged your hold, you tune in the VOR and identify that you have the right one. I set the "Pri Nav" on the PFD to VLOC1 (where I've tuned the VOR to hold over) and I also set the "Sec Nav" to point at VLOC1 as well to give me a bearing pointer to the station for reference purposes.

I would then turn the "Crs Set" knob on the PFD to indicate the inbound course for the hold. Looking at the CDI indication (Pri Nav) as well as the bearing pointer (Sec Nav) on the HSI I can easily determine a suggested heading to fly and enter the hold. While flying to the hold fix (remember, it is just a VOR this time) I will climb/descend to the altitude assigned by ATC. I'm guessing the best way to do this is with the autopilot (since that is what we are working on) so we'll assume that I'll just flying Heading and using the Bug to set our course.

During the time spent flying to the fix, I would get set up and do my calculations and diagrams. Draw the fix, determine the entry and then determine the inbound course to set up in Pri Nav. For example, if told to hold west of El Toro on the 270 radial with left turns (the default being right), I'll set the Pri Nav course to 090 degrees.

As I cross the fix, I'll spin the bug to my desired outbound heading for the entry (assuming teardrop or parallel) for one minute. This, of course, is the beginning of my six Ts. Time (start), Turn to correct heading for entry, Twist Crs for inbound (which I've already done), Throttle back (already slowed to 120 while approaching hold), Tune com (as needed) and finally Talk to ATC and advise of entry into the hold.

At the end of one minute, I begin the turn to the inbound course. If all is going well, this can be accomplished by leading the turn with the Heading bug and then once the turn is started hitting HDG NAV on the autopilot for the system to pick up the course on Pri Nav. While flying inbound, I can take the time that "Otto" is flying to spend more attention setting things up for the next step. Initially this will be determining the outbound course (in the example given, 270 degrees) keeping in mind any anticipated wind correction needed.

This is another great thing about the Avidyne PFD is right there next to the HSI is a wind indicator that shows you the wind's direction and strength which makes guessing at an outbound course so much easier.

So, with the bug now set to my outbound course (unless it is the reciprocal of our current heading in which case I would subtract it by 10 or 15 degrees to keep the autopilot from accidentally turning the wrong way to pick up the heading) I continue flying toward the station. Once I've passed the station and the flag flips to From instead of To, I'll press the HDG button on the auto pilot so that it will turn in the appropriate direction to acquire the heading indicated by the Heading bug. Once the turn is initiated, I'll place the bug where it needs to be in case I had to set it short of the outbound course.

Once I've passed the station again going outbound, I'll begin timing and off we go. From this point on, it is just a matter of refining the outbound course and the length of the outbound legs to ensure that we can get a good solid 1 minute inbound leg.

This seems like a pretty long way to describe what is going on, but it actually was quite simple. Anyone else out there have a differing technique they'd like to share? If so, please leave me a comment.

I'm hopeful that by documenting these procedures after I fly them, it will help reinforce them. Can't wait to see what kind of fun stuff we'll be doing on Friday morning!

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