Wednesday, January 02, 2008

Start Making Sense

Like many pilots, I subscribe to several aviation magazines and do a lot of reading to keep up to speed on changes and trends in aviation. I find some of them more useful than others. One magazine that I often find disappointing is Flying magazine. I probably wouldn't subscribe to it, but it's a freebie that comes with a membership to a professional organization to which I belong.

One of the reasons I find Flying magazine disappointing can often be traced to the editor, J. Mac McClellan and his opinion pieces. The January 2008 issue contains a McCellan commentary that doesn't fail to disappoint. Sorry if that's too many negatives - I mean to say I found his commentary disappointing because he attempts to explain how easy GPS and RNAV approaches are to execute with the Garmin 530/430 and G1000. Several of his statements irked me, the most obvious being his attempt to lay the blame for pilots' confusion in using these units at the feet of flight instructors and not where it belongs. To paraphrase the old Woody Allen joke, "Manufacturers (like Garmin) and the FAA have built a castle in the sky. Pilots and flight instructors live there."

But if this misplaced blame weren't enough, Mr. McCellan makes several assertions that he probably meant to be helpful, but are factually not true. His overly simplistic advice just might get a pilot into the danger zone. Jumping to the end of the commentary, McCellan closes with this claim:
The great news about WAAS is that just about every instrument approach looks like an ILS, can be flown like an ILS, and you don't need to learn how to do any extra button pushing. I think we want to make this seem hard because it's really so easy.
While the goal of the new RNAV approaches is to provide vertical guidance for every airport, it's not always possible. Sometimes the required WAAS service level is not present and all you get is LNAV with no vertical guidance whatsoever. It may make things more complex, but an instrument instructor would be remiss if he didn't prepare a pilot for such an eventuality.

The commentary starts off fine and there's a lot to agree with. A recurring theme for Mr. McCellan is that navigational systems should be simple and easier to use and I agree that there is a tradition that mires pilots (especially GA pilots) with unnecessary amounts of detail about how things work. Mr. McCellan points out that many GPS instructional courses start out describing the constellation of GPS satellites and include many layers of complexity that have no direct relationship to successfully flying an instrument approach. Then it goes South with this amazing claim.
The box itself, and the instrument approach chart, show you everything you need to fly approaches with WAAS, and they do it automatically with no need for additional training.
He then goes on to describe the Garmin product line in such glowing terms that it makes me wonder if we're using the same equipment. Perhaps someone from that corporation actually asked Mr. McCellan to write this piece to divert attention from the user interface mess they have created. It reads a lot like (gasp!) an advertisement.
But here's the rub that is baffling many pilots and their instructors—you can't modify the procedure if you elect to fly it as published. ... The system won't allow you to skip a holding pattern, for example, if that is part of the published procedure...
... Stay with a vectors to final approach every time you can, and life will be easy. When a full approach is necessary you must understand that a WAAS box will not skip a thing.
With all due respect - Bladerdash!

Consider the RNAV RWY 34 approach to Willits, California.

Assume you are located somewhere near the Mendocino VORTAC (ENI), are proceeding direct to O28 (Willits), and then you learn the weather is not so hot. You request the RNAV RWY 34 approach and Oakland Center clears you "direct HERMT, expect the RNAV runway 34 approach." So you press the PROC button and select the RNAV RWY 34 approach and select HERMT as the transition. As Mr. McCellan points out, selecting and activating an approach is relatively straightforward once you've done it a few dozen times.

Here's where the 530W/430W units are a bit smarter than the older versions. Since the Initial Approach Fix (IAF) you selected has a hold in lieu of a procedure turn, the unit asks if you want to fly the hold. Mr. McCellan's simplistic description doesn't mention this behavior and here's where the FAA's regulatory complexity keeps instrument flight instructors busy. 14 CFR 91.175 says, basically, that in our scenario you shouldn't expect to fly the procedure turn. If you want to do a turn in the hold, say for currency, you need to ask ATC and get their permission.

Let's say that in our scenario we actually want to do a turn in the hold, Oakland Center gives us permission, so we answer YES to this prompt.

We've selected the full procedure. You can see the magenta line leading to HERMT and the hold depicted in white. Mr. McCellan claims that once the holding option is selected, it cannot be changed. Again I wonder if we're using different equipment or if he's in need of some refresher training.

Let's throw a twist into the scenario and say that you just learned that heavy precipitation has been reported 10 miles northwest of the airport and it's moving southeast bound. You decide to skip the hold. Press the FPL button, press the small knob to enter cursor mode, scroll with the big knob so that the hold is highlighted. Now press CLR and when the unit asks if you really want to remove the hold, press ENT. Viola! The hold has been removed. What's more, if the autopilot was engaged in NAV mode and was taking you to HERMT, it will correctly sequence you through the rest of the approach.

I've written before about the dangers associated with selecting Vectors-to-Final when the approach contains stepdown fixes outside the FAF. The short version is that if you take Mr. McCellan's advice then you won't see the intermediate fixes and you might descend into cumulus granitus if you're not careful. There are some new features in the Garmin units that make it a bit easier to handle this and I'll cover that in a future post.

Flight instructors are an easy target for frustrated pilots and for magazine editors who are trying to put lipstick on a hog. The problem with these units is that the user interfaces are a mess and by approving of these units, the FAA's fingerprints are all over them.

It's obvious that many flying magazines are dependent on advertising revenue from aircraft and aviation equipment manufacturers. And I wouldn't be the first person to point out that this often leads the columnists writing for these magazines to avoid taking off the gloves and drawing attention to the flaws and shortcomings in these products. I, on the other hand, have no relationship with these manufacturers and no incentive to ... well ... fib. I receive no income from these manufactures and I'm offering these observations for free to anyone who cares to read this. If you value my unbiased perspectives, please consider making a donation using the link found in the upper right side of this page. The amount you choose to donate is up to you, but it will help me continue to set the record straight.

Oh, and Mac, if you're reading this, feel free to drop me a line next time your in the Bay Area. If you buy me a coffee, I'll give you some free ground instruction in the use of the 530W. Or we can just chat about why you feel the need to blame flight instructors ...


Dave Starr said...

Some good points, John, Happy New Year.

It's fortunate that Garmin builds an electrically and mechanically sound box, because they certainly could not survive on their usability features.

The interfaces are clearly designed by EE's and MSC's, who may or may not be pilots but are still thinking in "geek speak". A real opportunity for them to employ a usability expert who doesn't have a computer background.

RE: J mac? Well let's say I haven't subscribed to Flying since he took over. Sad to see the direction the magazine has taken. Comments about the 'ease and reliability' of GPS-based nav systems just scare me. Mac has many more degrees, hours and ratings than I, but I've worked directly with the GPS since the days there was only one satellite.

Great system, fantastic people, even a "sort of" interface between the FAA and the USAF (to make WAAS work), but it is just one tool and it certainly does not make approaches "simple".

Why the flight instructor gets blamed for Garmin's and the FAA's mess is beyond me ... they (CFI/CFII) don't pay for ads in Flying I guess.

Ron said...

I guess I'm the minority, but I've never been bothered by the VTF behavior of the Garmin boxes. It's true that you don't get the fixes (if any) outside the FAF, but then if it's a vectored approach, you're being vectored to the FAF anyway. Once students understand how the box works, it's a simple matter of adding a couple of numbers to know where you are in relation to any "missing" fix. This is also the sort of thing that the moving map is good for. I know, I know -- the map is not for navigation. But it is helpful for situational awareness.

Rule #1 for IFR flying is to always know where you are. If you do that, then there should never be any risk of running into terrain, no matter how the box works. Cross radials, bearing pointers, moving maps, distance countdowns to the FAF... each of these can help you figure out where you are.

I'm sure Garmin could improve the UI, but all in all it's the best one I've seen yet. Ever use an Apollo/UPS, Northstar, Bendix, or other comparable unit? Oy...

I think getting them to change the logic will be an uphill battle because every single GPS Garmin makes works the same way.

I echo your comments about Flying magazine. For years the editorial pages have exuded an snooty east coast vibe which hasn't set well with me. The AVwebs of the world are only hastening the downturn in Flying's subscription base, I think.

Happy new year to all!

John said...


I notice the ILS 19R into your home airport has only one intermediate fix. The two ILS approaches into Westchester County, which Mr. McCellan probably flies regularly, are set up beautifully for VTF since there are no intermediate fixes.

In fact, people in most parts of the country probably don't think about the problem with the way VTF is implemented because they tend to fly approaches with no intermediate approach course fixes.

An ILS approach I fly regularly has three intermediate fixes and the vectored version of this approach is often a whirlwind affair with "maintain maximum forward speed" thrown in for fun.

In all instances I can think of, the 530W, 430W and G1000 are not going to display these fixes during VTF on the moving map with the default configuration.

There is a sequence of button pushes one can do to make the Garmin units at least display intermediate fixes on a vectors-to-final approach. I'll cover than in a future post.

The bottom line is that computers are supposed to (and can) make the pilot's job easier, safer, and obviate the need for mental math. Make a math error at the end of a long flight and you could become a CFIT statistic.

So sorry, I think we'll have to agree to disagree on this one.

eric said...

John, when you say "14 CFR 91.175 says, basically, that in our scenario you shouldn't expect to fly the procedure turn" I'm a little confused as to why. I understand from section (j) that if you're receiving vectors to final or a fix, or if it says NoPT, but I'm not sure how being cleared direct to a fix factors in.

Does the FAA consider 'fly direct to xxxxx, cleared for the GPS' to be a radar vector?

John said...


Take a closer look at the approach chart and you notice an MSA sector (just above the inset airport diagram) that lists the sector approaching HERMT. In that MSA sector it says NoPT, still the 530W asks you if you want to load the hold or not.

A really good way to piss off a controller is to make an unexpected procedure turn, so unless you get permission you shouldn't load or fly the hold. The topic of procedure turns often causes considerable confusion, so it probably deserves its own post. I'll put something up in a day or two.

Anonymous said...

I'd have to agree with your comments about Flying, John. I don't my some of the columnist but Mac gets me (almost) every time. His flight reviews may as well be advertisements for the manufacturer.

Hardly unbiased. Doubtful if I'll renew my subscription when it comes due.


Grant said...

Why not just load the hold, and then when you determine you don't need to fly the hold, just activate the leg after the hold sequence?

I understand the user interface gripes on the 430/530 units, but I'm finding that most of those griping don't have a whole lot of time actually using the units. In fact, most frequently those complaining about the user interface haven't received instruction on the units, much less actually read the manual or downloaded the simulator.

While I don't agree with Mac that instructors are to blame, I certainly think they play a role that is left unfulfilled.

The fact is, if you have a Garmin product installed in your airplane, you are expected to know how to use it. Not just going Direct To, but know that product inside and out.

There is a line drawn in the sand when it comes to teaching flying, and teaching resource management. It used to be that flying required 90% of the training, and the other 10% went into teaching how to use the tools on the instrument panel.

Now that we've got tools in small airplanes that would make large airplane drivers jealous, that line in the sand is shifting. Aviation instructors are now required to be technology teachers as well as stick and rudder teachers... not exactly part of the glamorous aviation picture we have stored in our brains.

The fact is, many instructors don't realize that the new gadgetry in general aviation airplanes requires more ground-based training. The last thing instructors want to do is spend more time on the ground.

After all, we've got maneuvers to teach, right?

John said...


Who are you? I ask because your Blogger profile is hidden and, frankly, you sound like a shill for Garmin.

Taking the points in your comment in order:

Of course you can load the hold and delete it later, but you're off point. Mr. McCellan claimed an approach could not be altered once it was loaded and I was simply pointing out that it can indeed be edited.

I have witnessed countless pilot who significant experience with 430/530 and G1000 units make the same, frustrating mistakes. This points to a poorly designed user interface, not poorly trained pilots and negligent instructors.

One could make a career out of knowing a G1000 "inside and out." There are several levels of knowledge that I group into the categories of "need to know" and "nice to know" and "who cares?" Chapter 1 of the AIM has a very nice section on the task in which a pilot should be proficient for IFR.

Any instructor worth his or her salt knows that ground instruction is an important part of any pilot's training. You're barking up the wrong tree ...

Instructors have always been "technology teachers" in that we are required to teach all the systems and theory related to a particular aircraft. The poor user interface design in the Garmin products only makes an instructor's job harder.

So Grant, why don't you let us know more about your bona fide and your level of experience in providing technology instruction. I'm all ears.