II Morrow joins the IFR GPS world
II Morrow has borne tremendous scrutiny for being one of the last to certify an approach-capable GPS. No doubt the company's marketing staff has been grimacing every time the question "Where is it?" came before "It's almost ready. Just another month or so."
So you can imagine the company's relief finally to have the panel-mount Apollo NMS 2001 certified for en route and terminal navigation and nonprecision approaches. Previous iterations of the 2001 mated to a loran receiver were approved for en route and terminal IFR navigation. Now, however, the 2001 comes along as a standalone (no remote boxes necessary) approach-certified GPS. Current retail price is $4,995, with street prices around $3,700. Installation costs can add between $2,000 and $3,000, depending upon the equipment already in your airplane.
In converting the 2001 from VFR-only to IFR-capable, II Morrow carefully avoided monkeying with the unit's excellent user-interface logic. In other words, the programmers failed to make the box difficult to understand and hard to use. Accomplished users of the previous 2001s will find much familiar with the IFR- approved model. As with the previous model, this latest 2001 mates to optional external modules for loran input, a fuel-air data computer, various moving maps, and other-brand fuel computers.
As expected, the 2001 employs a complete database with airports, navaids, en route and approach fixes, special-use airspace, and sundry airport information. With the advent of GPS approaches, the number of named waypoints blossoms, so many of these approach-specific waypoints must be created within the 2001's expansive mind. Examples: points along an approach that correspond to DME fixes or when final- approach fixes must be created where there are none in the overlaid approach. Sometimes the labeling of these waypoints borders on the arcane.
The 2001's excellent dot-matrix LED display returns unaltered — it's a breeze to interpret in all kinds of lighting conditions, although it is conspicuously missing a moving map. It's become almost compulsory to have at least a rudimentary moving map in this class of GPS, so II Morrow has some catching up to do.
It's assumed that using any modern GPS should be a straightforward affair, so the acid test for the latest generation of IFR boxes is more narrowly focused: How well do they work and how easy are they to use in what is normally a high-workload environment? To see, we sampled several nonprecision approaches with the 2001 in a Beech Baron outfitted with the IFR box, as well as the optional loran sensor and air- data computer. II Morrow has certified the 2001 to be used with a variety of external course-guidance displays, from HSIs to dedicated miniature CDIs. Unlike most other approach models, the 2001 need not be connected to an external resolver input — that's the feedback from an HSI or CDI that tells the GPS the omnibearing selector (OBS) setting.
Setting up the 2001 for an approach is pretty uncomplicated. It's worth noting, though, that many requirements in TSO C129 — the governing text for approach- approvable GPSs — actually creates some fussiness. After flying with the 2001, two things are clear: One, the accuracy of course guidance is superb and remarkably steady — none of that needle-waggling so common with ground-based nonprecision approaches; and, two, actually flying the approach is notably more complicated than with conventional methods.
To activate the approach sequencing, you must pull up the current flight plan under the FPL button; universally in the 2001, touching a mode button twice returns you to the top page within the stack. Page over to the destination waypoint and punch SEL. The 2001 will prompt: "Load Approach?" Push ENT and you can scan through the approach choices by twisting the small data-entry knob. Find the one you want and hit ENT. The box will add the approach waypoints to the end of the flight plan, replacing the airport itself with the various approach coordinates. (You can assume the waypoint for the missed-approach point is the runway end.) Jab the NAV key to return to the main navigation page.
Assuming that you have made these entries well in advance of the destination, the 2001 will just sit there, navigating away. When you are 30 nm from the destination, the 2001 will flash the MSG light. Punch the MSG button and you'll be greeted with "push ENT to enable approach." Hit ENT and then you'll be prompted for the local altimeter setting. (If you load the approach into the flight plan within 30 nm of the destination, you will be prompted immediately.) The APPRCH remote annunciator will illuminate steadily, and the CDI scale will begin narrowing from the 5-nm en route to the 1-nm intermediate approach margins.
Nearing the initial approach fix (IAF), the 2001 flashes the MSG light again to warn of impending waypoint passage and issues instructions for the desired heading to the IAF. Once inside the IAF and about 3 nm from the final approach fix (FAF), the ACTIVE annunciator begins to flash. At 2 nm from the FAF, the CDI scale cranks down steadily from 1 nm to 0.3 nm. As you approach the FAF, the MSG will once again blink; the message is that you are close to the FAF. (Yes, there are a lot of blinking lights here.)
Once past the FAF, the ACTIVE annunciator will be on steadily; this is your confirmation that the GPS's brain, thanks to built-in receiver autonomous integrity monitoring (RAIM), believes that the satellites are healthy (and will be throughout the approach), the position resolution makes sense, and all the other details of setting up the approach have been executed properly. If the ACTIVE light is still blinking or is off, you are supposed to abort the approach. From the FAF to the missed-approach point (MAP), you simply fly the CDI, watch the distance and time count down, and start your search for terra firma.
Should you see nothing but deep gray at the MAP, you are expected to begin the missed-approach procedure. You have yet one more button to push, though, because the 2001 has illuminated its external OBS/HOLD annunciator/button, meaning that it has stopped sequencing along the approach flight plan in memory. If you intend to fly the published missed, you must jab this button to resume the sequencing of waypoints.
Aforesaid approach is, of course, the simplest kind — a straight-in with no procedure turn, DME arc, course reversal, or wrench-in-the-machine last-minute vectors that commonly take place out there. When you are confronted with the vagaries of real-world IFR flying, using the 2001 becomes a bit more complicated. The main issue is this: Because the box does not know about procedure turns or other pre-FAF antics, it aims to sequence along the approach waypoints by proximity. It tries to go to the nearest one. Assuming that you are flying a VOR overlay approach in which the IAF is the on-field VOR, you must remember to punch the OBS/HOLD button prior to crossing the VOR outbound for the procedure turn and then remember to push it again upon turning inbound on the final-approach course. So, at all times during the approach, you have to ask yourself, "Should the box be sequencing or not?"
Further complicating matters is the need for manual input of OBS. For example, say you have just crossed the VOR outbound to the procedure turn (as before, the VOR's on the field). You have already punched OBS/HOLD to stop flight plan sequencing. Now, after passing the VOR, you are expected to punch the direct-to key twice to set the OBS; twist the knobs to enter the desired inbound course back to the VOR. Upon turning inbound from the procedure turn, thunk the OBS/HOLD button again to resume sequencing.
How about DME arcs? II Morrow implements this function differently than the others. Rather than forming part of the approach flight plan, the DME "arc assist," as II Morrow calls it, is a supplementary function within the NAV menu. Instead of guiding the CDI needle around the arc, the 2001 simply gives you a heading to fly; the CDI needle stays aimed at the desired intercept course at the end of the arc. This implementation means that you must look at a different nav page (without time and speed information presented) and cannot slave the autopilot to fly the needle during this part of the approach. (II Morrow recommends using the heading mode.)
Naturally, the learning process for any kind of gear — particularly, sophisticated and capable nav equipment — can be daunting. (At least the 2001's manual is well- written and rife with excellent examples.) Most pilots, after a few dozen real GPS approaches, say that the confusion factor declines greatly. II Morrow has done an admirable job of keeping the old 2001's general simplicity while meeting the stringent needs of the approach TSO.
For more information, contact II Morrow Incorporated, 2345 Turner Road S.E., Salem, Oregon 97302; telephone 800/525-6726 or 503/581-8101; www.iimorrow.com.
