ADF Required?

[ArrowFlyer86]

We're doing some practice approaches this evening and I wanted to find a few new ones to try. I came across this one but it says that an ADF is required (unfortunately I don't have a working ADF) and I don't want to recommend an approach I couldn't actually fly!

What about this approach necessitates an ADF in order to do it? The IAF is a VOR and SEDLY looks like it can be identified as the intersection of the localizer and the OXI R-307 radial. Is there a component that I'm missing?

 

[Arnold]

The NDB is the missed approach holding fix. Before magenta lines the Compass Locator was an excellent too for SA during vectors for an approach.

 

[unsafervguy]

its required because the missed approach is a right hand turn directly to sedly, you can only do that with an adf or approved gps.

 

[ArrowFlyer86]

its required because the missed approach is a right hand turn directly to sedly, you can only do that with an adf or approved gps.

Thanks, that's helpful. I guess I wouldn't be able to go directly to it without an ADF or GPS. Thanks!

 

[Larry in TN]

you can only do that with an adf or approved gps.

Not just GPS, but any RNAV system that is approved to substitute for the applicable navaid.

 

[unsafervguy]

Not just GPS, but any RNAV system that is approved to substitute for the applicable navaid.

come on larry, its time to give up that king kns80....

 

[ArrowFlyer86]

come on larry, its time to give up that king kns80....

Get rid of a KNS80!? I'm hoping to upgrade to one! (joking)
I still have this ancient, inop brick in my plane

 

[Larry in TN]

come on larry, its time to give up that king kns80....

Never got to fly with a KNS-80. Those were just in the fancy corporate airplanes when I was learning to fly in the 1980s. They are a type of RNAV more accurately called a course-line computer. Back then, that was the only type of RNAV that was accessible to light GA airplanes.

Ten years ago I was flying 767s with DME/DME/IRU, without GPS updating. Those FMS systems were approved for terminal and enroute RNAV, including substituting for VOR and NDB waypoints. I even flew an Atlantic crossing, Miami to western Africa, in one. Once away from land, the FMS was ded-reckoning from IRS inputs for the rest of the crossing. As I recalled, we had a mile, or two, of map-shift when we coasted in at Senegal. Those 767s are still flying today without GPS.

I've also flown a CRJ with the GPS inoperative which left DME/DME updating for the FMS but still provided RNAV.

On that CRJ flight, the other pilot, who had learned to fly after GPS became common in GA airplanes, didn't understand that we still had RNAV capabilities with the GPS updating unavailable. To him, GPS, RNAV, and FMS were interchangeable terms. He knew the FMS had DME/DME updating from ground school but didn't understand what that really did.

That's why I point out the distinction when someone uses GPS interchangeably with RNAV. Instrument pilots should understand the difference.

 

[Mongoose Aviator]

That's why I point out the distinction when someone uses GPS interchangeably with RNAV. Instrument pilots should understand the difference.

I thought theses (RNAV & GPS) were interchangeable terms. I read your post a few times but am not really understanding it.

 

[Larry in TN]

I thought theses (RNAV & GPS) were interchangeable terms. I read your post a few times but am not really understanding it.

GPS is one type of RNAV. Many other technologies can provide RNAV which are not GPS.

 

[unsafervguy]

the kns80 that i was joking with larry about was one of the systems he was describing. it used vor and dme for the box to calculate the position of the waypoint and made it a pseudo vor and allowed direct navigation to it. it was pretty high tech for its day. some people still have them installed and use them.

 

[MauleSkinner]

I thought theses (RNAV & GPS) were interchangeable terms. I read your post a few times but am not really understanding it.

“RNAV” is short for “Area Navigation”, which has been around long before GPS, and can take (or has taken) many forms. VOR/DME, DME/DME/DME, LORAN come to mind.

These were fun to shoot approaches with…

 

[asicer]

“RNAV” is short for “Area Navigation”, which has been around long before GPS, and can take (or has taken) many forms. VOR/DME, DME/DME/DME, LORAN come to mind.

I didn't think VOR/DME is RNAV. And I think you only need 2 DumMiE's, not 3.

 

[MauleSkinner]

I didn't think VOR/DME is RNAV.

the unit I posted the picture of is a VOR/DME RNAV system, as is the KNS 80 that was mentioned.

And I think you only need 2 DumMiE's, not 3.

It takes 3 to triangulate a position. Two gives you a circle. It’s a lot like the way GPS does it, actually.

 

[Larry in TN]

and can take (or has taken) many forms. VOR/DME, DME/DME/DME, LORAN come to mind.

Loran-C, VLF/Omega, Doppler, Inertial reference (IRU), course-line computer, DME/DME/IRU, Cel-nav. Probably more.

These were fun to shoot approaches with…

That is a course-line computer, just not as advanced as the KNS-80.

I didn't think VOR/DME is RNAV. And I think you only need 2 DumMiE's, not 3.

The automated systems auto-tune VOR-DME, VORTAC, & LOC-DME and can use both the Rho and Theta data from multiple stations to update the FMS position. I've seen systems that can autotune either two, or three, stations simultaneously.

The IRU/FMS systems I've flown have all been in airliners. I'm sure there's a lot of combinations in corporate jets that I haven't seen.

 

[asicer]

the unit I posted the picture of is a VOR/DME RNAV system.

Suitable for an approach?

It takes 3 to triangulate a position. Two gives you a circle.

Hm, all the plates say "DME/DME". I suppose that nomenclature is a bit misleading.

 

[Pinecone]

FYI, you can't fly that approach with a KNS-80 (and yes, I have flown one in a GA-7), because SEDLY is either NDB or two radials.

With the KNS-80 you need a radial and distance to "offset" the VOR.

Just saying.

And yes, having a KNS-80 was the bee's knees back in the day.

 

[RussR]

Suitable for an approach?

Back when there were VOR/DME RNAV approaches, yes. And that wasn't that long ago, the last one was just canceled maybe 2 or 3 years ago.

 

[John Collins]

Suitable for an approach?

There used to be RNAV VOR/DME approaches and the KNS80 was approved for them using RNAV. All these approaches have since been removed from the NAS. I kept my KNS80 as my #2 Nav system because it allows me to fly RNAV direct with the remaining VORTAC or VOR/DME in the MON system. It also includes a DME, VOR receiver, and ILS receiver. So if GPS fails, I can still navigate. My #1 NAV is the GTN 750Xi.

 

[Larry in TN]

Suitable for an approach?

The installation documents will specify what a particular equipment installation is authorized to do. AIM Chapter 1 has a lot of information about this and the various systems and their capabilities.

Hm, all the plates say "DME/DME". I suppose that nomenclature is a bit misleading.

Such a system will auto-tune ground stations to get the data it needs. They often have only two receivers but those receives don't have to stay on a single frequency like a VOR or ILS receiver would.