Loading Airways: GNS 430?

[Lance F]

Hmm, doesn't sound like top-notch instruction to me.

SuperCubRick: Victor Airways have a simple design and are easy to understand. They are routes between two VORs. To fly along an airway, first tune the outbound VOR, set the published radial, and fly that radial. Then, halfway between the VORs (the standard COP, or change over point) switch to the inbound VOR and fly the published radial (you'll need to figure the reciprocal of what's on the chart). Every now and then you'll find a published, or nonstandard, COP where VOR service volumes or high terrain don't allow for the standard "halfway" COP.

If your instructor believes the airway will randomly change course between fixes published along the airway, he's incorrect. Fixes in the form of DME fixes or cross-radial fixes are published along the airway after the airway has already been born. They are used as reporting points, holding fixes, etc.

The ONLY time you'll ever need to adjust your course/ground track (and therefore heading) is at the COP. If there happens to be a fix at the COP, it's just a coincidence. Hope this helps.

What you're saying is not accurate. There are many Victor airways that make major heading changes between VORs. These occur at fixes/intersections which can be anywhere between the VORs and there may be multiple changes like this between VORs. You have to enter each of these waypoints in the 430/530 flight plan to follow the airway.

There are many examples of these in the northeast. The only chart I happen to have at home is L-20. Take a look at V415 between Foothills (ODF) and Rome (RMG). The airway takes a 19 degree turn at EYNUH.

It is for these airways that not having them available in the 430/530 is such a PITA. Flying them without GPS at all (1 or 2 VORs) is real work.

 

[n9088d]

I'm aware of all of that - I didn't just fall off the back of the ol' turnip truck. :laff:

You're learning instruments. You're not yet instrument rated, so you certainly did "just fall off the ol' turnip truck!"

Pulling your leg. Good luck.

 

[n9088d]

What you're saying is not accurate. There are many Victor airways that make major heading changes between VORs. These occur at fixes/intersections which can be anywhere between the VORs and there may be multiple changes like this between VORs. You have to enter each of these waypoints in the 430/530 flight plan to follow the airway.

There are many examples of these in the northeast. The only chart I happen to have at home is L-20. Take a look at V415 between Foothills (ODF) and Rome (RMG). The airway takes a 19 degree turn at EYNUH.

It is for these airways that not having them available in the 430/530 is such a PITA. Flying them without GPS at all (1 or 2 VORs) is real work.

Thanks for your reply. I recently sent one of my instrument students up for a checkride and I sat in on the oral. The DPE asked my student several questions about Victor Airways regarding COPs (unpublished vs. published) and proper procedures for flying airways in the event of GPS failure. Heck, I remember when I took my instrument checkride years ago we didn't have GPS. The DPE stressed to my student that GPS is NOT required to fly airways. To some of us who've been around a few years this is a silly point to make, as we (and many others before us) have been flying airways for some time without GPS.

You have to enter each of these waypoints in the 430/530 flight plan to follow the airway.

Let me remind you that a pilot absolutely does not need any RNAV capability to fly an airway. Saying you have to use GPS to fly the airway is just plain old wrong.

I was able to review the airway you mentioned. According to you, I couldn't fly V415 without a GPS. I'll address this with two points. First, sure I could! Let's say I'm equipped with dual VOR indicators and no GPS. I'd fly outbound from Rome on the 059 as charted. I'd pass YESVU, PIMEE, and UTIDE with no course change. Once I reached NELLO (defined as the intersection of the Rome 059 and Foothills 258), I'd turn right to intercept the Foothills 258 (with 078 set in my OBS) as charted. Again, with no GPS. Then I'd simply track the Foothills 258 inbound to the station. Please note that I'd pass several additional fixes along V415 with no course change on my way to Foothills. As you can see, V415 is quite simply defined by two VOR radials: the Rome 059 and the Foothills 258. This is exactly as I discussed in my previous post. NELLO intersection is located at the COP for increased positional awareness as it defines a significant change in course. Please understand that any fixes along a Victor Airway are only "piggy-backing" the airway. A pilot need not consider any type of course change until reaching the COP (which COULD be co-located with a fix, or it might not be).

If you're using GPS as primary means of flying an airway, you're using improper procedure. I remember this coming up on my CFII checkride several years ago as well. The GPS course line will NOT coincide with the airway necessarily. If you need further convincing... I've got a close friend who is a controller at Kansas City Center. He routinely works a sector where he observes pilots who are evidently improperly attempting to navigate an airway using GPS. This becomes obvious to him as the aircraft nears the COP and is several miles south of the airway centerline (almost outside of the 4 mile airway boundary, which is there for your protection). I'll remind you that all aircraft are expected to follow the centerline of the airway. Tracking a GPS line as opposed to flying published radials is guaranteed to make you first diverge then slowly re-converge with the airway centerline (even if the deviation is slight). If you don't believe me, go out VFR and configure your VOR indicator(s) appropriately to track a chosen airway. Then configure your GPS to fly the airway. Track your GPS line and notice how the CDI on your VOR indicator(s) slowly drifts away from center. You will have proven to yourself that you are indeed drifting away from the airway centerline and violating approved procedures.

Many pilots are positively reinforced when they fly airways using GPS because many times ATC won't call them on it due to the small (sometimes virtually no) difference in track. But at the end of the day, it's simply the wrong way to do it.

Regarding changeover points. Allow me to cite the AIM:

5-3-6. Changeover Points (COPs) ​

a. COPs are prescribed for Federal airways, jet routes, area navigation routes, or other direct routes for which an MEA is designated under 14 CFR Part 95. The COP is a point along the route or airway segment between two adjacent navigation facilities or waypoints where changeover in navigation guidance should occur. At this point, the pilot should change navigation receiver frequency from the station behind the aircraft to the station ahead.
b. The COP is normally located midway between the navigation facilities for straight route segments, or at the intersection of radials or courses forming a dogleg in the case of dogleg route segments. When the COP is NOT located at the midway point, aeronautical charts will depict the COP location and give the mileage to the radio aids.
c. COPs are established for the purpose of preventing loss of navigation guidance, to prevent frequency interference from other facilities, and to prevent use of different facilities by different aircraft in the same airspace. Pilots are urged to observe COPs to the fullest extent.

===================

You also mentioned a 19 degree course change at NELLO. You've touched on another common misconception that leads some pilots into thinking if both radials (from both VORs) that define the airway are the same that they can fly the entire segment using only one of the stations (given they can receive that station throughtout the entire segment). This is not true. Since no two stations are located at the same position on the surface, no two radials are created equal. The 028 from the first VOR is not the same as the 208 (when flown inbound) from the second VOR. The radials don't parallel each other. We may only be talking a fraction of a degree, but nonetheless. Therefore, it is invalid to compare the angular difference (for any reason) between two VOR radials. Imagine a no-wind situation for the sake of discussion. The turn at NELLO might require more OR less than 19 degrees.

 

[RPJ]

This becomes obvious to him as the aircraft nears the COP and is several miles south of the airway centerline (almost outside of the 4 mile airway boundary, which is there for your protection). I'll remind you that all aircraft are expected to follow the centerline of the airway.

Remember that a VOR receiver is allowed a certain amount of error, 4 or 6 degrees depending on testing method. This will have the aircrafts track not on the "exact" airway centerline. As long as the aircraft is withing the airways lateral boundaries it is legal and does not necessarily matter.

 

[MidlifeFlyer]

I'm aware of all of that - I didn't just fall off the back of the ol' turnip truck. :laff:

I think he likes that method because it gives you precise distance and ETA to the next fix in case ATC asks, doesn't make sense if you're in radar contact, they know where you are. I guess it'd be good information to have for position reporting in a non-radar environment.

For position reporting, you have the display that shows when you cross it even if it's not part of the flight plan.

It might be the "do more than needed during training" that is typical in flight training. Putting in every waypoint along the route sounds like the IFR version of checking time/speed/distance calculations every 10 miles in primary training.

But it seems to me that leaving them out and then asking that one or another be inserted en route ("proceed direct") - twirling the dials while you have other tasks to preform, maybe in actual, is a much more useful skill than twirling them on the ground.

Frankly, I's ask the instructor why he wants me to do the extra work. There may be a very good reason.

 

[roundout]

I prefer to input them all manually on the ground. That way, if ATC clears you direct to an intersection on the waypoint, or gives you a clearance limit and a holding pattern 5nm ahead when you're doing 200kts or better, you're prepared. I mean really, it takes 2 minutes, which is probably how long you have to hold for release anyway.

 

[Lance F]

Please don't forget that if the GPS meets FAA TSO C146a (as the 430W and 530W do) it absolutely can be used as the primary source of navigation. You do not need any VOR receivers to be legal and to navigate airways with this equipment, and ATC will be quite happy with the route you fly.

and btw I never said you needed RNAV to navigate an airway. I just pointed out that this statement "The ONLY time you'll ever need to adjust your course/ground track (and therefore heading) is at the COP" is incorrect. There are many fixes along many airways that require a course change that are not COPs, and I pointed one out as an example. Whether one makes that change by GPS or VOR/DME was not my point.

 

[Douglas]

Do it while taxiing out or holding on the ground waiting for takeoff clearance - he'll taxi out / do the pre-takeoff checks. Sometimes he'll enter them all in for me though, and I'll double check him. He's 62, retired airline guy, so he isn't looking for ways to milk students for $ I don't think, lol.

I am certain not milking my students when I am introducing them to instrument approaches, IFR communications, a GPS unit they have never used before and sometimes they have never even flown a piper before.

Loading the GPS on the ground is a great way to teach them how to use the GPS and grasp the GPS in a shorter amount of time. Save the "drinking from a fire hose" until later.

my .02 cents on why i do it and I am not milking.