Decision Attitude

Decision Altitude in instrument flying is the lowest altitude possible on a precision approach (ILS, LPV, LNAV/VNAV). At the specified altitude you either see the runway and land or fail to see the runway and immediately start the missed approach procedure. It used to be called decision height, but height is something we never really know. Altitude is what barometers measure.

But right now I have reached the decision attitude, at least in regard to instrument charts.

In the United States we have two major sources of charts, a government agency called NACO, which is an acronym for National Aeronautical Charting Office and Jeppesen, a commercial vendor. The charts show the same information with slightly different formats, and one pilot I know dismissed a rather loud airport lounge debate about which was better with "Some like chocolate. Some like vanilla." End of discussion.

Other countries have similar situations: charts come from Jeppesen or a government or at least quasi-governmental agency.

I started instrument training in 1985, and some may say that I still don't get it. No matter: since 1985 I have used Jeppesen charts for my instrument flying. A few years ago at the Oshkosh fly-in I bought a pair of beautiful green leather Jeppesen binders with Arabic calligraphy and the English legend "Royal Air Maroc B-737 Operations Manual." I kept the contents for reference; I use the binders for my charts.

[I promise to take a picture and post it over the weekend.]

But lately I have been less satisfied with the Jeppesen charts. First, they moved a lot of their NOTAMs online, which isn't much help in the cockpit. I wrote them a letter, and got a perfunctory response. And this was a big change: it used to be that Jeppesen's customer service was the best there was.

They missed a change of a Minimum Enroute Altitude (MEA), which I suppose can happen to any chart service. I found out the semi-hard way when ATC told me that I couldn't be cleared via the airway at the altitude I'd used for many years. "But my [brand new] chart doesn't show an MEA change," I complained. ATC was right.

That was the semi-hard way to discover an MEA change. The hard way would be to hit some rocks.

My flying changed, too. I'm not flying the King Airs anymore, so don't need faraway charts at short notice. The company bought Jeppesen charts for the airplanes, but I never knew who had done the revisions, and some of the pilots were better than others at refiling charts after flights. I didn't want to find myself someplace strange in the middle of the night with the approach chart misfiled. So I carried my own charts, at my own expense.

And expense has become a big issue. I got my Jeppesen renewal notice today; they want $281 for the year. But NACO charts are public domain and are available free online, from sites like FltPlan.com, airnav, or FlightAware. A subscription to NACO charts for 99% of my flying will cost about $105, which I can pay as the charts are issued, rather than all at once. In the past few months, $176 has become a lot of money.

So the decision is made; while I'll miss Jeppesen's approach, tomorrow I plan to stop at a pilot shop and buy a couple of NACO books and an enroute chart or two.

I'll sure miss using those green binders, though. Ebay, anyone?

Instrument Departures

The IFR world is always changing, and change comes faster and faster.  

In the old days, there were two main sources of instrument charts in the USA, the government (under a continually changing variety of names) and  Jeppesen, a commercial provider.  I still use Jeppesen charts for most of my flying, but now government charts, which are public domain, are widely available on the internet, through sites like AOPA, FltPlan.com, Airnav, and probably others. For this trip, I have downloaded government charts for the airports I am likely to use, although I am unlikely to fly IFR.

Let me say it out loud: I am unlikely to fly IFR because the airplane does not have an IFR GPS.  Yes, I can and may fly IFR, but the lack of a GPS makes it much more difficult, and it reduces the options.

This was reinforced while catching up on my chart revisions.  (Actually, I was getting ahead, since some of the charts are not valid until Thursday, but I determined that none of them will affect my flying between now and then.)  One of the advantages of the Jeppesen charts is that they tell you why the chart has changed.   Lately, there have been a lot of changes to departure procedures.

Departure procedures are strange to begin with.  Generally, they are optional.    They are not optional when Air Traffic Control (ATC) includes the departure procedure in a clearance, which they will do if they need it for separation.  This tells me that when a departure procedure changes, ATC would like to use the new one in order to move more airplanes more efficiently.  Why change a procedure that has worked for 20 years unless you want to actually use the new procedure?  (It used to be that the exact statement about departure procedure being pilot's choice was only published in the controller's handbook, not in any publication for pilots, but now it is in the FAA's Instrument Procedures Handbook, FAA-H-8261, available online.)

Look first at Driggs, Idaho.  (Unless you have a Jeppesen subscription you'll have to wait until Thursday to look, because charts are not available online until they become effective.)  The chart had a minor change this time around, but in looking it over I noticed that there is no non-GPS departure.  There are no ground-based navaids at Driggs, which is in a narrow U-shaped valley, so the only alternative to a GPS-based departure is to pick a smart heading, climb steeply,  and hope that the winds aloft forecast is correct.  There is no radar coverage, so nobody looks over your shoulder.  No thank you.

The Cherokee Six we're in this week has DME but no GPS. Suppose that we decide to stop for lunch at Driggs on the way home (the restaurant there is excellent), and find that we need to depart IFR. No can do! This alone wouldn't keep us from stopping, but it still makes me pause.

Next, look at Pocatello, Idaho, which has a new departure procedure, even though the old one had worked well keeping airplanes out of the rocks for at least 15 years.  The new procedure involves a "departure gate" at SICOY; in other words, every departure ends up about 13 miles west of the airport, even for an easterly flight.  Also, you need DME (or some equivalent) to identify SICOY, so many KPIH-based airplanes cannot fly the procedure.  You can see SICOY on the VOR 3 chart at right.

I think a lot of Pocatello-based pilots will react to the change by saying "ATC seldom clears us via the departure procedure." But this is may be about to change.  Pocatello is generally below radar coverage, so ATC keeps airplanes apart procedurally.  The old departure procedure used the same airspace as the ILS missed approach, which meant that no airplane could depart while another was on the approach.  Now, ATC can send the departure to SICOY and be sure that the missed approach area is clear.  In other words, it will be easier to get out of Pocatello, as long as you have DME.

If you keep or rent an airplane in Pocatello, you have to ask whether departure delays will cost enough to justify an avionics upgrade.