N4184R After

Adelaide, AU (C172)
Microlights in Strethalbyn
Pipers in Sedona
Oshkosh 2002
Maui Fly-about
Sedona Jan 2003
March RAFB - Mar 2003
Flying Trips


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Here is what N4184R looks like after the avionics panel replacement.

n4184r new panel leftl.jpg (148330 bytes)This is the left side of the new panel.  Notice that the AI has a flight director, and below that a Sandel SN3308 HSI.  The Sandel is a very cool instrument.  With two bearing pointers, a GPS or Heading pointer, a moving map display, including the flight track from the Garmins, and the WX-500 Stormscope data, this instrument is pure pleasure to use.

In the far left, there is a backup electric AI, to use if the vacuum system or the primary AI ever fails.  I considered putting this on the far right side of the panel, for use by the co-pilot, but this would have meant having to move some of the engine instruments, which would have mean more FAA paperwork and approval.  No thanks.

n4184r new panel middle.jpg (139502 bytes)This is a picture of the middle of the new panel.  On the left, you can see the new altimeter and VSI, the auto-pilot control panel and indicators, and the #2 VOR indicator.  At the top of the middle "stack" is the PS Engineering PE7000MS audio panel & intercomm.  Underneath are the two Garmin GPSes: a GNS 530 and a GNS 430.  Below them are the avionics power switches.

The GNS 530 and 430 pair are a dual system of GPS receivers, with embedded communication and navigation radios. The GPSes are interconnected for "flight plan flow through", which means that if the #1 GPS fails, the #2 GPS carries on, uninterrupted, including sending signals to the autopilot and SN3308.  Also, if either GPS fails, the GNSes are designed with internal dual backplanes, so that their nav/comm radios remain independent of GPS power and electrical problems.  The only problem which will affect both the GPS and radios is if the display screen goes out (in which case #2 display is available).

I use the top GNS for flight plan setup, display, and tracking, and the bottom GNS for radio work, frequency tracking, and other information that the GNSes are capable of displaying.  While I'm fiddling with the knobs on #2, the #1 display continues showing the current flight plan.

n4184r new panel right.jpg (128452 bytes)This is the right side of the new panel. You can see the Garmins on the left side.  The next "stack" is the S-Tec System 55X auto-pilot main control panel, the Garmin GTX-327 digital transponder, the original King DME (it's still a useful instrument for IFR, even though the GPSes can also show distance), and then the AM/FM radio/CD player.  

The radio, in conjunction with the awesome features of the PS7000MS, has come in very handy for those long 3 and 4 hour flights across the Midwest.  The CD is a very handy way to keep the kids entertained; the music can be switched off for the crew, while the kids continue enjoying it. And, when the co-pilot is playing arbitrator to the squabbling kids, the "Isolate" switch is very handy to keep the pilot from missing any communications.

Here is another "pilot's view" of the new panel:

n4184r pilot panel.jpg (165237 bytes)You can see the DVR-300 clock on the far left, below the electric AI.


The system, as a whole, works very well.   As part of my pre-flight:

  • I program the flight plan into the GPSes (which can store 20 plans for easy later reuse).
  • For checklists, it's possible to use either the plastic one (that I bought), the audible one that I programmed into the DVR-300, or the visual one that I programmed into the GPSes.
  • Set the altitude alerter to the proper barometer setting (along with the altimeter, of course).
  • Dial the HSI's bug to the assigned departure heading
  • Set the altitude alerter at the clearance altitude (typically 1500 or 3000).

After takeoff:

  • I place the S-Tec S55 autopilot into "HDG" mode, and with VS set to "+7" or higher (at sea level).  At this point, the plane will track to the HDG bug on the SN3308, and climb at +700 FPM until it reaches the altitude programmed into the altitude alerter, at which point it will level off.
  • If I am assigned new headings, I dial the HDG bug accordingly, and the plane tracks.
  • If I am assigned or released from an altitude restriction, I push "VS" on the autopilot control and dial in the appropriate climb rate.

One of my friends, also a pilot, once said to me: "You're not flying a plane; you're playing a video game!"  This guy is even more of a geek than I, so I took it as a compliment.

Establishing the Flight Plan:

  • When released from the assigned heading, I then hit the "FP" button on the #1 GNS, which shows the flight plan, indicating the current (first) waypoint.
  • Since the flight track to the first waypoint is based on an origin of somewhere at the airport, and since we're no longer at the airport, I hit the "direct" button, and redirect the flight plan from our current location, instead of some reference point at the departure airport.
  • A second later, the GPS flight plan is established, I hit the "GPSS/HDG" button, and switch to GPSS mode, which causes the autopilot to track to the GPS flight plan instead of the HSI heading bug, even though the autopilot is in HDG mode.  Often, there will be a slight turn to track since we'll have moved on from the point at which the new flight track origin had been reset.
  • Alternatively, I could push the "NAV" button on the auto-pilot, which causes it to take its input from the current "NAV" source. 

    This is the part that gets interesting: The Sandel 3308 HSI has a "NAV" source button (top left) which controls which input source is to be used for navigation.  It can be one of "GPS1", "GPS2", "Nav1", "Nav2", "ILS1" and "ILS2".  The latter two are actually the same physical source as the two Navs, but show "ILS" when the frequency range is that of a localizer.

    Anyway, with the autpilot in "NAV" mode, it and the Garmins can be switched between having GPS and NAV as the input source with the Sandel's Nav button, or with the "GPS/VLOC" button on either Garmin.   It may sound complicated but it's actually quite intuitive.  It's harder to explain than it is to use.

Reaching cruise altitude:

  • Once we've reached our assigned altitude, and assuming that I've correctly entered the right numbers into the altitude alerter, the autopilot should level off at that altitude.
  • It's important to understand and remember that the autopilot knows nothing about airspeed.  If you program a vertical speed that is not possible for the airplane (eg: 800 FPM at 10,000 ft.), the autopilot will dutifully trim the plane in a valiant but futile attempt to set the right pitch to achieve that rate of climb, and, if you don't recognize the problem soon enough, it will stall the plane.

For "fun", I often tune the navigation radios to the upcoming or nearby VORs or NDBs, and enable the SN3308 bearing pointers so that I can triangulate and confirm location with means other than just the GPS.

Another fun thing: to get the current "winds", the GPS has a page which automatically displays the current wind speed and direction.  I often use this page as I am approaching an airport, and during the downwind leg to confirm the winds based on GPS calculations.  The ATIS, ASOS or AWOS information may not be local to the airport, and it may not be current, so having the GPS provide real-time wind numbers is very handy.  Of course, I always look for the wind sock at the airport, too.  Technology makes things fun, but always have a backup to technology -- because it will fail at some point.

On the AUX pages, the Garmins have Fuel Planning pages, by which an estimate of fuel needed to reach the programmed destination, as well as fuel remaining upon arrival can be reviewed.  It's based on input including the current fuel flow.

There is also a Trip Planning page in the AUX section of the Garmins, with which the total time enroute as well as the destination local time can be reviewed.

The Garmins and autopilot are also incredibly helpful during IFR flights.  Since GPS navigation includes a CDI indicator, the Garmins are a legal substitute when suffering a partial panel failure of the DG (in my case, the Sandel HSI) and/or AI.

I received my IFR certificate in July, 2002, and I've been flying IFR consistently ever since.

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Alan K. Stebbens Flying Website - Last updated: 04/13/2003