VOR/DME Arc

[Terry]

Hi All:

I am having trouble staying on the 10 mile DME arc. I fly in to Hays, KS. on the 078 radial. I would have a heading of 258*. When I get to 11 miles out I turn north and then tune the 068 radial. I hold my 10 mile DME arc for about 1 to 2 twists of turning the VOR and then I seem to drift out to 11 or 12 miles.

Any suggestions? I am working on my IFR with 20 hours of hood time. I am doing this on my simulator.

Thanks;

Terry

 

[spiderweb]

If you are holding the Arc for that long and then losing it, it is probably a simple matter of not scanning the DME as much once you are on the arc. Question: how are you making your corrections once on that Arc? Perhaps a more aggressive cut, and more aggressive scanning of the DME would help.

What is/are your primary instruments once on the Arc?

Hi All:

I am having trouble staying on the 10 mile DME arc. I fly in to Hays, KS. on the 078 radial. I would have a heading of 258*. When I get to 11 miles out I turn north and then tune the 068 radial. I hold my 10 mile DME arc for about 1 to 2 twists of turning the VOR and then I seem to drift out to 11 or 12 miles.

Any suggestions? I am working on my IFR with 20 hours of hood time. I am doing this on my simulator.

Thanks;

Terry

 

[Areeda]

Terry,

There's a lot of ways to do this the way I've been teaching is as follows. I assume we're talking about the VOR/DME RWY 16 http://www.naco.faa.gov/d-tpp/0513/05440VD16.PDF

As you said you are approaching on the 078 radial heading is 258. When you get about 0.5 nm before the 10 DME point you turn right until 248 is at the 9 o'clock (heading is 338), tune the VOR to 248 you will start with a full scale left deflection. Note that the 0.5 nm assumes a speed of about 100 kts, adjust as necessary.

Now tune the VOR 10° into the arc for a left turn this would go to 238°. Turn to put 238 at the 9 o'clock position. Now watching the DME when it goes to 10.1 you want to turn another 10 deg into the arc so the VOR setting would be at the 8 o'clock (approx) position. If the DME goes to 9.9 you delay your next turn, if it goes more than that you can turn to the right and to put the VOR setting at 10 o'clock.

Everytime the VOR needle centers tune 10° and turn 10°, keep the VOR heading at the 9 o'clock position as long as the DME is set right.

PTS says you have 1 mile, but you should be able to do it to .2 or so.

Hope that helps. I really like using the DG and the VOR as "graphical computers" to do all the calculations. It takes a little practice to get it but it is very simple and much easier to do under pressure than addition and subtraction.

Joe

 

[Bill]

I was taught similar to Joe, and distilled:

1. Turn in 0.5 DME from your IAF, standard rate.
2. Initially fly heading of radial +/- 100 degrees depending on direction of flight.
3. Continue to fly heading radial +/- 100 degrees, but closely monitor DME as you may need to modify based on wind direction and strength. (I've flown anywhere from radial +/- 80 to radial +/- 130 to stay on ARC.

 

[Areeda]

One thing I forgot to explain (at least).

The reason you want the TO indication on the VOR is so that when you do the last tuning to 170° it will be the inbound course. The lead to start your turn to final will be a bit less than ½ scale deflection maybe as little as ¼ scale. It depends on the DME distance and speed.

Joe

 

[Bill]

One thing I forgot to explain (at least).

The reason you want the TO indication on the VOR is so that when you do the last tuning to 170° it will be the inbound course. The lead to start your turn to final will be a bit less than ½ scale deflection maybe as little as ¼ scale. It depends on the DME distance and speed.

Ah! Depends on equipment. The 172 I used had two NAV's, the upper nav head OBS was set to inbound, and the lower VOR head has "ARC" (I believe it stands for automatic radial centering), a little known gizmo that some older heads had. If I push on the OBS knob (spring loaded, pops back out to middle position), an orange led comes on and the VOR will automatically center the needle on the "TO" bearing. Yup, the OBS ring spins around, then it hunts back and forth, and stops with needle centered, and the light goes out. In the middle position, you can spin the OBS knob like any other VOR head. The fun begins if you pull on the knob (it locks out in this position), the led comes back on, and the VOR head continually tracks your "FROM" radial.

So, using the lower nav/vor head in tracking mode, the VOR continually shows my my "FROM" radial without further input. Thus, I use nav2 to trak my from radial, and add/subtract my 100 to get headings. I know when we're getting close to leadin, as it is not hard at all to know your reciprical to your inbound heading.

 

[Areeda]

ARC sounds pretty cool, I've never seen such a thing.

DVORs and Radial mode of some NAV radio's help alot with SA.

That's not to mention a good GPS that puts the purple line on the map.

Joe

 

[Terry]

Ben, Areeda, and Bill:

Thanks All.

I was mainly forgetting my scan.

Also I didn't like turning to final with the VOR opposite of my heading. (If I use this method will the DE approve?)

I am printing out the information and will try this again.

Thanks!!!!

Terry B)

 

[Areeda]

I was mainly forgetting my scan.

Spend as much time in the sim as possible. Works wonders for the scan. I assume it's a low cost PC program. If you can get to the point you can deal with the program requiring mouse input, the cat jumping on your lap, a kid screaming for attention, the better half requesting emergency maintenance and still hold altitude and heading you're ready for the test (and hard IMC to minimums).

Also I didn't like turning to final with the VOR opposite of my heading. (If I use this method will the DE approve?)

IMHO this is the best way to do it. I can't imagine a DE not approving. Their job is to test to standards not teach a method. The PTS does not say anything about how you set up the instruments.

That said if your double eye taught you differently, do it her way, please.

Joe

 

[Terry]

Areeda:

Thanks for the input. I was able to hold the DME Arc to within .6 of the Arc.

I tried VOR to minimums and missed the runway. I'll stay on the FS4 as long as necessary. ( I have yoke and rudder controls and a real hefty computer.)

I have passed my written (90%) but had to stop flying due to some unexpected expenses. I have over 20 hours under the hood but thought I would use the simulator until March when I can start the flying up again.

I will be changing CFII's and would like to be real profeccient when I start again.

Thanks;

Terry

 

[gismo]

Areeda:

Thanks for the input. I was able to hold the DME Arc to within .6 of the Arc.

I tried VOR to minimums and missed the runway. I'll stay on the FS4 as long as necessary. ( I have yoke and rudder controls and a real hefty computer.)

I have passed my written (90%) but had to stop flying due to some unexpected expenses. I have over 20 hours under the hood but thought I would use the simulator until March when I can start the flying up again.

I will be changing CFII's and would like to be real profeccient when I start again.

Thanks;

Terry

First, I strongly suggest you spend at least 20% of your time on the PC sim with a CFII. It's awfully easy to fall into bad habits and the more you practice them the more trouble they will be in the long run. Second if your CFI teaches a different method than what Areeda offered, I would discuss that method with the CFII rather than abandon it. Unless you are in a part 141 school, most good CFI's will accomodate variations in what they teach especially if it works for the student.

 

[Areeda]

First, I strongly suggest you spend at least 20% of your time on the PC sim with a CFII. It's awfully easy to fall into bad habits and the more you practice them the more trouble they will be in the long run. .

I agree with Lance, although I would put a time like once every 2 weeks rather than a percentage. Most double eyes I know will come to your place and work with you on your simulator for their regular hourly rate, if you're not too far away.

I would suggest you set up exercises with the II and review them and the procedures you're using on a regular basis. The cost will be more than made up by reduced time in the aircraft once you start up again.

Second if your CFI teaches a different method than what Areeda offered, I would discuss that method with the CFII rather than abandon it. Unless you are in a part 141 school, most good CFI's will accomodate variations in what they teach especially if it works for the student.

I would be a bit stronger here (Lance probably would too but he's polite). The value of learning a procedure from some guy on the Internet vs. learning it from the II who's going to sign your logbook should be obvious. If your II wants you to do it differently, forget what I said. You can discuss it with her or in this thread but the difference is one is from a trusted source and the other is just bits from the ether.

Joe

 

[Terry]

Hi All:

The owner called from the aircraft rental and I am meeting with my new CFII this Friday.

While I can't afford to start right away I could afford to pay him to spend some time on the simulator with me.

The meeting is set up for Friday morning. Will keep everyone posted.

Thanks;

Terry

p.s.> My wife informed me if I cleared out the lilacs and made her a new flower bed that she probably could find some extra cash to let me start my training by late January.
So today I dug out the chain saw and commenced to "buzz" the lilacs with "turns around a point" and "short field" wacks. This is no weekend project.
Not complaining. We have been married +34 years and she is my flying partner.

 

[Eamon]

A DME arc can also be done by watching you bank angle on the AI & just adjusting according to the DME. I find this much easier than using the VOR. I found that using the VOR took too much scan time. doing all the twisting, etc.

This may or may not hold true with Y'all.