Value of DME

Caramon13 said:
Show me where on the DME it says turn left. Or right. Or anything that provides lateral guidance of any sort. It's a number. There is no guidance. What if you turned left at SLOAF, DME is still going to show 26 if you are on a left arc, there's nothing to show you on the DME that you should have turned right instead.

An ADF shows you where to go, it's a big gauge with an ARROW. A DME does NOT show you where to go. Not sure why this is so hard. You are looking at a map and you see 26, your DME says 20. Doesn't show you how to get to 26. You are using the MAP for guidance.
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By this standard NDB, VOR and LOC/ILS give you no lateral guidance.
 
My vote would be to keep it. If you loose the GPS, or it's signal, you will be happy that you have DME.
 
Caramon13 said:
The SLOAF waypoint is identified by the lateral guidance of the VOR and the distance from the DME, you fly the DME arc based on the distance from the VOR. The radials are from the VOR, THEY provide lateral guidance.

Show me where on the DME it says turn left. Or right. Or anything that provides lateral guidance of any sort. It's a number. There is no guidance. What if you turned left at SLOAF, DME is still going to show 26 if you are on a left arc, there's nothing to show you on the DME that you should have turned right instead.

An ADF shows you where to go, it's a big gauge with an ARROW. A DME does NOT show you where to go. Not sure why this is so hard. You are looking at a map and you see 26, your DME says 20. Doesn't show you how to get to 26. You are using the MAP for guidance.

DME determines how far away you are from a point. If you are left or right of that point, but the same distance, it doesn't care does it? Similar, VOR's are lateral, not distance. If you tune in a VOR you won't know how far you are from it, but you'll know which way to turn to get to it.

Turning left or right to get a number higher or lower isn't lateral guidance.
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OK, let's take a step back.

I'm not saying that DME's general purpose is lateral guidance. But what does the FAA's rule that GPS can be substituted for DME unless the DME is providing lateral guidance on final approach mean, if DME cannot provide lateral guidance in the first place?

Now... Let's look at THIS APPROACH. You're on final. What instrument is telling you whether you are on course, to the left or to the right of course?
 
I disagree that DME doesn't provide lateral guidance on an arc. That's what it's for. Nothing about "guidance" says anything about how it's presented to the user. The CDI is just one way. The DME readout, the ADF bearing pointer, an RMI, your moving map are all ways of getting lateral guidance.
 
My car is a 6 speed manual transmission. The GPS will do everything you need until its degraded or off line. I love reporting VOR radial plus DME mileage for position on initial contact for ATC requests. It is precise and simple. VOR is not going away for the next 20 years. Folks,,,,there is even talk of bringing Loran back, (the military is talking about it/it is resistant to EMP interference). I am an analog man in a digital world.
 
n2230b said:
My car is a 6 speed manual transmission. The GPS will do everything you need until its degraded or off line. I love reporting VOR radial plus DME mileage for position on initial contact for ATC requests. It is precise and simple. VOR is not going away for the next 20 years. Folks,,,,there is even talk of bringing Loran back, (the military is talking about it/it is resistant to EMP interference). I am an analog man in a digital world.
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You can report VOR/DME position with your GPS
 
just completed some panel work, I had my DME removed. Did I use it? Only once in a great while, and that was just to check the distance compared to what the GPS said......Do I miss it? Nope.
 
I do not have a panel mount gps...use my DME regularly when flying ILS approaches in my area.
 
I would pull the DME from the plane before my IFR check ride. It would not be worth failing a check ride on something you would never realistically use in real IFR. Now if you are an older pilot and you have used the DME a lot, and you train on the use of DME on a regular basis and use it as one of you IFR 6 month approaches. Then I would keep it, if not, move on and put the time, money and learning into buying and using a gps system.
 
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