Radials, HSI, Reciprocals, oh my

[Champcar]

Well Holds and DME arcs are putting a snag on my progress. I thought I had Radials all figured out for a non HSI aircraft. My HSI question is do you use it just as you would with a NAV like in the 172. For example when flying to the station you put the radial you want to fly on the tail of the pointer or just put the pointer on the radial since a HSI does not allow reverse sensing? i dunno why that confuses me.

Reciprocals are killing me when doing holds and arcs, Im having alot of trouble figuring them out in my head, and am constantly messing things up in the aircraft. I have used te +2 -2 rule but i forget it all the damn time like a idiot. UGGHH!!

end rant.

 

[dpilot83]

As far as reciprocals are concerned, the 2s rule is nice when you don't have anything else, but in my opinion, the fastest way to do it as far as practical application is concerned if you're struggling with it is to look at the heading on your DG or Nav1 or something like that and then look at the opposite side of the same instrument to see the reciprocal of that heading.

In answer to your HSI question, my opinion is that you should always twist in the proper radial even if the HSI will track it either way, which it almost always will. There are two primary reasons for this. Number one, if you ever fly anything with an autopilot, it will always try to turn towards the head of the needle in the normal nav mode, so it's good to be in the habit in preperation for that.

The other thing is, there is one instance where if you are sloppy about which way you twist it in, the HSI can still give you reverse sensing. To prevent yourself from becoming lazy in the manner you twist it in, you should always properly select the radial you want to fly.

The instance where the HSI will give you reverse sensing is going to be a little further down the road in your training I would imagine so don't worry about it for now. Just work on being a professional in the small details for now and it will help you out later.

 

[Airdale]

Holds and DME Arcs - These always present some trouble for Instrument students in the beginning. Here's some tips for you that I usually tell my students.

First, make sure you always tune to the station when flying to the station. Despite the HSI not reverse sensing, improperly tuning the HSI can give you incorrect flag indications, and thus confuse you as to which side of the station you are on.

For Holds:

Remember that all VOR stations have radials stemming from the station. From being the key word. So the 360 radial, is the radial that departs the VOR on a 360 heading. So to track the 360 radial TO the station, would be a magnetic heading of 180. When tracking the 360 outbound from the station, your magnetic heading will be 360.

That being said, when told to hold on a radial, you outbound course will always be the radial. So if you are told to hold west on the 270 radial, standard turns (Right), your outbound heading is 270. So if your hold entry were to be a teardrop, you would subtract 30 degrees from the outbound course to determine your heading to fly when crossing the fix (250). Once you determine your entry, I teach my students to use the 5 T's as their steps for entering the hold:
Turn to a new heading first
Twist the HSI to the inbound course (always tune to the fix)
Time, when wings level or abeam the fix, whichever occurs last
Throttle, adjust to maintain proper holding speed
Talk to ATC as required

I throw out the tune part, because you're already tuned to the station and have identified the frequency.

For hold pattern entry, I teach my students the thumb method using the HSI. For more info PM me. Too much to write on here!

DME Arcs are easy with an HSI. At .5 DME from the start of your arc, first turn 90 degrees in the direction of the arc, then twist the HSI until it centers (remember, tune to the station). Once it centers, keep flying until its half scale deflection, then turn 10 degrees and twist the HSI 10 degrees, or until it centers. Then repeat the process.

You'll get the hang of it, and once you do, you'll see how easy it is.

 

[Champcar]

Thanks for the tips. I understand holds, I have no problem on the entries, I nailed the holds in the sim. But when I get in the airplane for some reason a become lost. I think i just need to stick to the procedures and not try to make sense of it.

 

[Airdale]

Thanks for the tips. I understand holds, I have no problem on the entries, I nailed the holds in the sim. But when I get in the airplane for some reason a become lost. I think i just need to stick to the procedures and not try to make sense of it.

Ah yes, the typical " I left my brain on the ground " syndrome.

You'll understand it much better with experience, just nail the procedures and you'll be fine.