Navigating w/out DME,GPS, or VOR Cross Radials?

[akpilot907]

Hey all, I've had yet another brain fart..

This is what happens to you when you deploy...and not to mention I'm a low time IFR Pilot. I was sitting in my tent the other day planning an IFR trip to fly when I get back from this deployment and it struck me.. The airplane I have access to back home does not have a DME, approved IFR enroute GPS, (but it does have an 8 year out of date KLN 89b)... Now the airplane has dual VOR's and an ADF <----(CAN YOU BELIEVE IT!!)

If you guys/gals take a look at the chart I've attached, it's an Alaskan IFR Low chart... VORs are far and between.. and even the ones that look close, have 6,000ft MTs in the way.. so the lowest MEA in the state you can prob find is no less than 8-9,000ft.. Anywho, How do I identify a VOR change over point, and Identify a FIX (That doesn't have a VOR Cross radial)?? Can I use my KLN 89b (Which is an IFR GPS but the last it was current was in 2002) for DME reference only?

Thanks for the help guys!

 

[akpilot907]

Flight is from: PAFA FAI V480 ENN V436 TKA

 

[Marauder]

Flight is from: PAFA FAI V480 ENN V436 TKA

The changeover point is this symbol:

So, you would need a means to identify it... Answer: You would calculate the changeover by your flightplan time over the fix. Take a look at the V438 airway next to this airway. There is a DME symbol for distance, not on this airway. Even if you had DME, you couldn't identify it. The expired GPS could be used if you can verify that the expired database hasn't changed for this area (using a chart).

 

[SbestCFII]

Short answer is yes, if the unit is installed in an IFR certified configuration you can use the KLN89B as a legal substitute for ADF / DME even if the database is out of date and ID the VOR COP by DME. You can also use it for enroute navigation with the expired database, legally. However you must have current charts. All that being said, I'd update the database since it's still supported by Jeppeson. If the database is up-to-date the unit can also be used to fly LNAV (non-precision) GPS approaches.

I used a KLN-89B and it's color-cousin the KLN-94 for a number of years before finally switching to the Garmin 430W. If the unit works and the display isn't shot, then it's still a pretty decent unit to have.

 

[Marauder]

Short answer is yes, if the unit is installed in an IFR certified configuration you can use the KLN89B as a legal substitute for ADF / DME even if the database is out of date and ID the VOR COP by DME. You can also use it for enroute navigation with the expired database, legally. However you must have current charts. All that being said, I'd update the database since it's still supported by Jeppeson. If the database is up-to-date the unit can also be used to fly LNAV (non-precision) GPS approaches.

I used a KLN-89B and it's color-cousin the KLN-94 for a number of years before finally switching to the Garmin 430W. If the unit works and the display isn't shot, then it's still a pretty decent unit to have.

I don't know the 89 series. This airway does not look like it has an approved DME fix for the changeover point (unlike V438 next to it). Isn't he required to time the changeover point if it isn't marked identifiable by DME?

 

[aterpster]

Flight is from: PAFA FAI V480 ENN V436 TKA

In the old days we old guys flew IFR with two (sometimes one) VOR and no DME.

The change-over point was part of our flight log, which we estimated just like any other fix or VOR.

 

[roncachamp]

Hey all, I've had yet another brain fart..

This is what happens to you when you deploy...and not to mention I'm a low time IFR Pilot. I was sitting in my tent the other day planning an IFR trip to fly when I get back from this deployment and it struck me.. The airplane I have access to back home does not have a DME, approved IFR enroute GPS, (but it does have an 8 year out of date KLN 89b)... Now the airplane has dual VOR's and an ADF <----(CAN YOU BELIEVE IT!!)

If you guys/gals take a look at the chart I've attached, it's an Alaskan IFR Low chart... VORs are far and between.. and even the ones that look close, have 6,000ft MTs in the way.. so the lowest MEA in the state you can prob find is no less than 8-9,000ft.. Anywho, How do I identify a VOR change over point, and Identify a FIX (That doesn't have a VOR Cross radial)?? Can I use my KLN 89b (Which is an IFR GPS but the last it was current was in 2002) for DME reference only?

Thanks for the help guys!

Why do you have to identify it? Nothing happens there, there's no course or altitude change, and it's not a reporting point. The ENN R-171 and TKA R-352 radials do not simply end at the COP. It's not like a switch is thrown and you go from a strong signal to no signal. You've got two VORs and an ADF, have one of them on ENN and the other one on TKA, and get Summit NDB on your ADF. The COP looks to be about a 210 bearing from the NDB, you should have a good signal from TKA before you reach that point.

And go ahead and use your KLN 89b if you want to.

 

[poadeleted20]

So, you would need a means to identify it... Answer: You would calculate the changeover by your flightplan time over the fix.

Yup -- just like we did it 40+ years ago when we didn't have DME in most light singles and GPS didn't exist.

 

[poadeleted20]

I don't know the 89 series. This airway does not look like it has an approved DME fix for the changeover point (unlike V438 next to it). Isn't he required to time the changeover point if it isn't marked identifiable by DME?

No. An IFR GPS will do for the crossover point distance measurement as long as the database is current or the coordinates of the navaid you're using haven't changed (check waypoint data in GPS against current A/FD).

But it wouldn't hurt to note the times anyway just in case the GPS crumps, either itself or due to a RAIM issue.

 

[jonnyjetprop]

What Ron said. Time it using a known ground speed (asking ATC) or estimated using winds aloft.

Thank you for your service. Hope you come home soon.

Hey all, I've had yet another brain fart..

This is what happens to you when you deploy...and not to mention I'm a low time IFR Pilot. I was sitting in my tent the other day planning an IFR trip to fly when I get back from this deployment and it struck me.. The airplane I have access to back home does not have a DME, approved IFR enroute GPS, (but it does have an 8 year out of date KLN 89b)... Now the airplane has dual VOR's and an ADF <----(CAN YOU BELIEVE IT!!)

If you guys/gals take a look at the chart I've attached, it's an Alaskan IFR Low chart... VORs are far and between.. and even the ones that look close, have 6,000ft MTs in the way.. so the lowest MEA in the state you can prob find is no less than 8-9,000ft.. Anywho, How do I identify a VOR change over point, and Identify a FIX (That doesn't have a VOR Cross radial)?? Can I use my KLN 89b (Which is an IFR GPS but the last it was current was in 2002) for DME reference only?

Thanks for the help guys!

 

[akpilot907]

The changeover point is this symbol:

So, you would need a means to identify it... Answer: You would calculate the changeover by your flightplan time over the fix. Take a look at the V438 airway next to this airway. There is a DME symbol for distance, not on this airway. Even if you had DME, you couldn't identify it. The expired GPS could be used if you can verify that the expired database hasn't changed for this area (using a chart).

What do you mean, "Even if you had DME, you couldn't identify this VOR COP"?? The DME distances are listed on the COP symbol...

 

[RussR]

Technically, those are not DME distances, they are just along-airway distances. Consider if neither VOR/DME or VORTAC had DME - in other words, a normal VOR. The distances would still be charted, but there'd be no DME source to even get the distances from. DME is shown with the number inside the "fat D" symbol, with the exception of if the along-airway distance is printed, and it's the same, then by an open "arrow" symbol. Check the chart legend.

Yes, the mileage would be the same, but this COP is not a DME fix, and there's no guarantee that the DME signal has been checked at that location.

Many pilots forget that the abbreviation "DME" doesn't mean simply "distance".

 

[Marauder]

What do you mean, "Even if you had DME, you couldn't identify this VOR COP"?? The DME distances are listed on the COP symbol...

An example of a DME symbol can be found on the next airway over. The COP as was mentioned previously on the picture above can only be identified through timing. If it can be identified by DME, then the D symbol will be there.

 

[akpilot907]

An example of a DME symbol can be found on the next airway over. The COP as was mentioned previously on the picture above can only be identified through timing. If it can be identified by DME, then the D symbol will be there.

Even if, both NAVAIDs are DME equiped (VOR-DME, VORTAC) and the VOR COP is depicted, you can't use DME to identify it? Only timing..? Yet again, there's GPS for situational awareness.. but if thats not legal, you have to use timing? And I know that COP's are not a right now, lets go, better hurry type of depiction.

Definition of COP: VOR Changeover Point giving mileage to NAVAIDs... So you can't use DME to reference that

 

[Marauder]

Even if, both NAVAIDs are DME equiped (VOR-DME, VORTAC) and the VOR COP is depicted, you can't use DME to identify it? Only timing..? Yet again, there's GPS for situational awareness.. but if thats not legal, you have to use timing? And I know that COP's are not a right now, lets go, better hurry type of depiction.

Definition of COP: VOR Changeover Point giving mileage to NAVAIDs... So you can't use DME to reference that

If it doesn't have the DME symbol then, no, you can't use it. Keep in mind, it doesn't mean it you won't be able to see the DME distance, but something is preventing it from being a reliable measure. Maybe in certain atmospheric conditions the DME signal is degraded or lost.

The two airways I depicted are relatively close to each other. There is a reason one has the symbol and the other doesn't.

 

[Marauder]

My guess some of those higher peaks on V436 are the problem with DME reception.

 

[akpilot907]

ok.. That makes sense... Now, here is another question.. If, there is no COP symbol depicted, and two airways you are using have a bend in the airway and the other with nothing (Using halfway distance) you can at that point, assuming both VOR's/VORTAC's are DME equiped, use DME... correct?

 

[akpilot907]

Also, can you use an IFR certified GPS to identify (DME) on that VOR COP on V436?? If it has an outdated database, you can check that the NAVAIDs haven't changed, correct?? Sorry about the questions, I think I've finally figured out what you've been trying to say.

 

[Marauder]

ok.. That makes sense... Now, here is another question.. If, there is no COP symbol depicted, and two airways you are using have a bend in the airway and the other with nothing (Using halfway distance) you can at that point, assuming both VOR's/VORTAC's are DME equiped, use DME... correct?

Nope. The only time you can use DME is when you see the D symbol with the distance number in it. This is the only way you know you will get reliable DME distance. Here is an example of an airway, where would you change over? Test time...

 

[Marauder]

Little wider view

 

[Marauder]

Also, can you use an IFR certified GPS to identify (DME) on that VOR COP on V436?? If it has an outdated database, you can check that the NAVAIDs haven't changed, correct?? Sorry about the questions, I think I've finally figured out what you've been trying to say.

V436 doesn't have a DME indicator, just a COP. You can use the GPS (assuming you verified the data) to determine how far you are down the airway. In this case it is not being used as a DME replacement since there is no DME distance indicating the COP.

 

[akpilot907]

because there is a bend in the airway, you would change over at ZEZJA intesction.. correct?

 

[Dr. O]

98% of IFR flights in Alaska have a Non-IFR certified Garmin on the yoke as the primary means of navigation.
And yeah, 40 years ago I flew IFR with one VOR radio and an NDB and a stop watch. It worked then and it works now. I like my Garmin better though.

 

[akpilot907]

Marauder,

That makes complete sense!! Now I remember a flight I made on a cross country ferry a CAP182 up from Anchorage to Fairbanks that was equipped with a DME... When I got out to about...oh, I'd say 30-40 miles, the DME stopped counting.. It just froze at the 33.7nm range.. I was like, HUH? "Tapped the display".. Damn thing is broken.. Now I know! Thanks

 

[aterpster]

because there is a bend in the airway, you would change over at ZEZJA intesction.. correct?

Correct. ZEZJA is a CNF (computer navigation fix). If you have an IFR RNAV navigator with airways, ZEZJA will automatically be part of V-513 should you load that airway including the segment from LVT to EWO (or EWO to LVT).

If your IFR navigator doesn't have airways all the fixes in this example will be in the database, including ZEZJA.

 

[akpilot907]

thanks aterpster! I love to always be learning...

 

[RussR]

because there is a bend in the airway, you would change over at ZEZJA intesction.. correct?

Right, you fly one radial until the other one centers up, then fly that one. In the typical case of a two-VOR receiver setup, this is elementary.

I also want to comment on the "straight-line" COP's though, I think we're getting wrapped around this idea that you have to know exactly where the COP is, and when to switch over. But think about how this works out in practice:

You have one VOR in Nav 1, the other VOR in NAV 2. There's no turn.
You fly VOR 1 for a while. At some point you'll start receiving VOR 2 while still using VOR 1.
At first VOR 2 might be wavering around a little, but soon it'll settle down as you get closer.
Then you're flying using both of them to cross-check the other - they may differ a little bit, but likely not more than a few degrees.
When you get close to the COP, you start to mentally switch the one you're following from VOR 1 to VOR 2, and just keep flying that one.
It's not like the signal from VOR 1 is all-of-a-sudden unusable at the COP, and VOR 2 isn't receivable until that point.

The comments about not being able to use DME are also a little bit strongly worded. If you have it, use it. Maybe not rely on it, since it's not a charted DME fix, but if it shows you getting close to the COP, you just start shifting your focus to VOR 2.

It doesn't need to be quite as precise as most of the rest of instrument flying.

 

[akpilot907]

I really do appreciate the responses.. I know I'm over thinking this and concentrating to much on the topic, but when I'm learning something new, I don't just say.. Gotcha! I like to understand why it's done a certain way, how it works, etc... Thanks again for the help..

 

[coma24]

Since the CNF was brought up, it's worth pointing out that CNF's shouldn't be referred to by name when working with ATC. They're unlikely to have a CNF depicted on the scope. As far as they're concerned, that's just where the airway magically bends.

 

[aterpster]

Since the CNF was brought up, it's worth pointing out that CNF's shouldn't be referred to by name when working with ATC. They're unlikely to have a CNF depicted on the scope. As far as they're concerned, that's just where the airway magically bends.

They have no knowledge of CNFs nor are they in the center database.

 

[roncachamp]

Since the CNF was brought up, it's worth pointing out that CNF's shouldn't be referred to by name when working with ATC. They're unlikely to have a CNF depicted on the scope. As far as they're concerned, that's just where the airway magically bends.

Do you mean they're unlikely to have the name of the fix on the scope? If so, you're right, but the names of fixes generally are not on the scope at all. They may not even have the airway depicted on the scope. At least not on the base map. Fix names, including CNFs, do appear on controller charts.

 

[roncachamp]

They have no knowledge of CNFs nor are they in the center database.

CNFs appear on controller charts. Since they have no ATC function that's pretty much all the knowledge that's needed. CNFs are in center databases.

 

[aterpster]

CNFs appear on controller charts. Since they have no ATC function that's pretty much all the knowledge that's needed. CNFs are in center databases.

On FAA en route charts of course, which center controllers have, just as pilots have.

Since you weren't a center controller can you provide an authoritative reference that CNFs are in center databases?

 

[roncachamp]

On FAA en route charts of course, which center controllers have, just as pilots have.

Controller Charts are a monochrome blend of low and high altitude enroute charts. They're not readily available to pilots.

Since you weren't a center controller can you provide an authoritative reference that CNFs are in center databases?

I was a center controller for nine years. The Flight Data Processing computers located in ARTCCs serve that center as well as the terminal facilities they interface with. TRACONs have their own Radar Data Processing, but not Flight Data Processing. I know CNFs are in the database because the computer accepts them.

 

[aterpster]

Controller Charts are a monochrome blend of low and high altitude enroute charts. They're not readily available to pilots.



I was a center controller for nine years. The Flight Data Processing computers located in ARTCCs serve that center as well as the terminal facilities they interface with. TRACONs have their own Radar Data Processing, but not Flight Data Processing. I know CNFs are in the database because the computer accepts them.

This is from the current DER:

Presumably this is in ZID's database.

So, why couldn't ATC clear me to ZEZJA?

0
VICTOR ROUTE NO. V513 15868
0
FACILITY OR FIX MAG 24550
INTERSECTION IDENT LATITUDE LONGITUDE ARTCC VAR FIX TYPE 142972
LVT LVT 36 35 04.2 085 09 59.8 ZID +02 VORTAC 96168
CENUD CENUD 36 56 24.4 085 23 32.9 ZID RPRT PT 93229
ZEZJA ZEZJA 37 06 37.6 085 30 05.4 ZID CNF 73687
OJETO OJETO 37 12 24.7 085 32 00.8 ZID RPRT PT 93301
GHOUT GHOUT 37 17 07.0 085 33 34.9 ZID RPRT PT 93910
EWO EWO 37 37 54.5 085 40 33.2 ZID -01 VOR 80062
JBEAM JBEAM 37 47 27.7 085 38 34.2 ZID RPRT PT 93025
BRBON BRBON 37 50 09.9 085 38 00.3 ZID RPRT PT 93201
IIU IIU 38 06 12.5 085 34 38.8 ZID -01 VORTAC 95674
0

 

[roncachamp]

Presumably this is in ZID's database.

So, why couldn't ATC clear me to ZEZJA?

I don't know, perhaps the controller examined the AIM at some point and learned CNFs "are not to be used for any air traffic control (ATC) application". CNFs are not mentioned at all in Order JO 7110.65 so there's no general prohibition on clearing an aircraft direct to them.

In any case, you can see that it wasn't because the CNF wasn't in the database. Why did you want to be cleared to ZEZJA?

 

[aterpster]

I don't know, perhaps the controller examined the AIM at some point and learned CNFs "are not to be used for any air traffic control (ATC) application". CNFs are not mentioned at all in Order JO 7110.65 so there's no general prohibition on clearing an aircraft direct to them.

In any case, you can see that it wasn't because the CNF wasn't in the database. Why did you want to be cleared to ZEZJA?

It was an academic question.