Sunrise Aviation

Last month I started in on what must surely be the most complex of all skill areas confronting new IFR pilots–setup and preparation for final vector/approach clearance. The complexity stems from two sources: clearance information comes very quickly, and the penalties for getting the details wrong are severe.

Before getting on with the details, it is essential to make a couple of philosophic points. IFR approach is arguably the most dangerous element of instrument flight. Consider the following: once you receive approach clearance, for the first time since initial departure you are free to change altitude without specific instructions to do so. And now the changes are all down, each one bringing you closer to unseen obstacles below. How close? How about 250' on a VOR/GPS approach? Or, even more impressive, 115' on an ILS? In virtually any other activity, this proximity to potential disaster would be enough to bring the OSHA folks running, violation papers in hand.

But not in aviation, where it is assumed every PIC has the skill and knowledge necessary to survive some impressively risky situations. It's a great freedom, but one that demands sophisticated understanding.

Most pilots have some sort of mental checklist to assist with organization of the competing elements involved in getting set up for an approach; mine is AHARMMMS–flawed and incomplete, but still good enough to have proved a life saver more than once. I dealt with the first two items–ATIS (or ADVISORY at non-towered fields) and HEADING–last time. Now it's time to see how much progress can be made on the remainder of the list.

AHARMMMS: ALTITUDE.
I have run into a number of pilots who use this item as a reminder to set the altimeter. I have a better idea. To start with, your altimeter should have been set on receipt of ATIS, the first item on the list. Failing that, at the very least the altimeter is updated regularly by ATC and should be current at this point in the flight. That said, if you need to set the instrument now, go ahead, then put some attention on the real action item facing you at this point in the checklist: a check of your current altitude to see how it blends into the planned approach. As an example, if you are several thousand feet above initial segment altitude or glide slope intercept altitude, it is clear you'll need to descend. Some awareness of this helps with your expectation of what is going to come next. And if you're really high, it might be time to call and ask for a lower altitude–better that than finding later you have to come down more quickly than you want.

When on radar vectors, your most recently assigned altitude often provides very specific clues to ATC's intentions. Using the John Wayne ILS approach as an example, any assigned altitude above 3300' leaves open the possibility of joining the approach outside Snake. Once you receive an assignment below 3300', you can count on joining inside that fix–very useful information for planning purposes.

AHARMMMS
The next item is misleading: a single "R" for radios. In fact, there are three or four times as many things to do at this point than on any of the other checklist items. The possibilities are so extensive, I expect the examination to consume the remainder of this month's available space. Throughout, I intend to concentrate on a "classic" GA radio setup: two VHF navcoms, DME and ADF. For those equipped with and planning to use more modern equipment–GPS, moving maps, VNAV, etc.–the substitutions should be fairly straightforward.

NAV 1: Common sense dictates that whenever possible the nav radios come first: there is little value in getting your com radios all lined up for contacting the tower or the CTAF if the necessary navaids aren't ready for use. Thus, if you plan an ILS, start with the #1 VHF nav receiver: it should be tuned, idented and checked for orientation to the localizer and glide slope.

Of course, as mentioned last month, none of this may be possible–and here begins some of the complexity. If the #1 nav is already doing duty keeping you on an airway or perhaps a feeder route, you can't very well just switch to another facility. What I find most workable when this happens is to make a loud mental note, "Nav #1 to go," then move on.

Before I move to the next step in radio setup, here is an important point: after tuning and identifying a new station, there is a critical last action–orientation. Pilots often feel rushed during approach setup, but it is essential to take the time to verify that nav indications make sense after you tune each receiver. Again using the John Wayne plate, and assuming vectors from the west, the expectation is for a left needle (provided you are close enough to the course–30°–for the indicator to read accurately). Equally important is orientation to the glide slope (GS) indication. Ideally, you are below, but it is common during some stages of vectoring to be above, waiting for instructions to descend to a more comfortable position. When you take the time to check the GS and find yourself above the course, it plants an important red flag.

NAV 2: Now the #2 VHF. Again using the John Wayne ILS approach, this would be set to the Seal Beach VOR for general orientation and backup on the approach. As indicated above, the decision which course to pre-select–058° or 077°–is determined by position and expectation. As with the localizer/glide slope, it is essential to go all the way through each of the required steps as you initialize the navaid: tune, ident, twist the OBS and orient to the needle and flag indications.

DME: Next comes DME, quite useful on this approach. While not all localizers are equipped with DME, there is reasonable likelihood of the navaid showing up. When it does, DME is approved as a substitute for the outer marker (OM) and can mark step down fixes and the missed approach point on Localizer-only procedures. In addition to these formal roles, DME is extremely helpful for general situational awareness: all through the approach, its indications provide a clear and accurate picture of your progress, both prior to course interception and subsequently as you descend toward the airport. A small amount of time invested in reviewing the DME numbers before starting the approach will do wonders for your ability to visualize your position–almost as good as a map.

ADF: Don't skip this one, even if your ADF skills are rusty. A quick look at the approach chart shows a Compass Locator–an NDB–at the Middle Marker site. In the absence of a moving map display, this navaid is even more useful than DME in boosting situational awareness prior to interception of the localizer course. By tuning in Maagg and then remaining oriented, it becomes easy to see your relationship to the localizer long before the localizer needle itself becomes active on the panel. As an example, if you are proceeding on vectors outbound from Seal Beach, the localizer gives you no help at all until you are within 2.5° degrees of its centerline. By contrast, the ADF shows the closing angle all the way from the VOR to the localizer: first an angle of approximately 115° and then less with every mile as you progress toward the northeast–extremely useful data for planning purposes.

COM RADIOS: Fortunately, we are just about at the end–one radio to go, whichever of the two coms is not currently in use monitoring ATC. Set it to the tower frequency or the CTAF, and you're done. The only exception I can think of would occur if you were doing all this work before getting switched to the final controller. In that circumstance, with one more radio switch still in your future, it might make sense to delay putting in the tower frequency, knowing it will get bumped when the last ATC switch comes in.

Next month, more AHARMMS: the rest of the list.