March 2012
How Do You Eat an Elephant?
How do you eat an elephant? You do it—one bite at a time. That’s the way replacement avionics get into most panels—one item at a time. Whether you order a whole new avionics suite at one time or have to develop an incremental plan for VFR or IFR upgrades, I recommend sitting down with a good avionics shop to chart your course. Here is a story of one journey following multiple Garmin upgrades with a bucket list for future additions.Garmin’s GTN (Garmin Touchscreen Navigator) series announcement woke me up to the fact that our aircraft’s avionics redo, which started in 1999 with a Garmin GNS 430, plus audio panel, GTX 320 simple transponder and L-3 Stormscope, might be due for some new upgrades.
At the time I installed the 430, the buzz was all about the risk of combining a Com/Nav-GPS navigator in one box. This was counter to the accepted avionics architecture of the late 1990s. The 430 was the new GPS navigator on the market at that time and was different from everyone else’s units.
Next came the GDL 49 NEXRAD receiver that—with a microcode update to the 430—offered General Aviation access to satellite weather downloads. The GDL 69 soon followed and today offers NEXRAD, winds, cell movement and lightning displays.
Watching weather and navigating with one 430 unit created too much information for one display. Adding a GNS 530 provided multifunction display and navigation backup. The GPSS (Global Position Satellite Steering) installation was the low cost addition and provided Nav tracking similar to the high dollar business jet long-range navigation/autopilot systems.
The GTX 330 Mode S transponder created another low cost entry to traffic advisories (Traffic Information System, or TIS) for Class B and C airspace. Suddenly I was able to see traffic between two and six miles that was invisible to normal eyesight. WAAS upgrades to the GNS 430/530 introduced ILS-like localizer precision vertical guidance (LPV) approaches with rock solid lateral and vertical guidance.
All of this occurred one step at a time over an eight-year period, one somewhat-financially-digestible upgrade at a time. Installing all of these features at one time would have called for writing a big check, but choosing the right foundation made all of these incremental upgrades possible.
What Next?
The question now is what to do next—upgrade the current GNS systems to GTN systems, or replace the steam gauge “six-pack” with a Garmin 500 glass panel? Either route’s cost is approximately the same, about $20,000. The question is, what is more important: improved situational awareness in the air and on the ground, or significantly improved ease of use with GTN’s user-friendly touch screen interface?
GTN 650/750
The difference between operating GNS 430/530 and GTN 650/750 systems is comparable to changing from using a pre-Windows MS/DOS computer to a current state- of-the-art Apple iMac. The “wow!” factor is tremendous.
The process for selecting and loading an approach is a prime example of GTN’s reduced workload. Selecting and loading an approach in GTN navigator requires only six screen touches, versus a GNS unit’s 16 button pushes and knob twists. For a General Aviation single-pilot operation in instrument conditions, this is a significant workload reduction. What do you get when going to a GTN installation?
- Larger screen size (The 750’s screen is 50 percent larger than the 530’s)
• Touch screen input
• Victor airways
• Rubber band route changes (This feature lets you grab any leg of your flight plan route and move it to accommodate a deviation or ATC amendment to your flight plan.)
• Brighter and clearer screens
• Alpha and Numeric inputs
• Flight charts – NACA and Jeppesen approach plates
• Safe Taxi diagrams for situational awareness at large airports
• Most major functions are no more than two touches away
Garmin’s GTN tutorial link at the end of this article contains videos describing how these new navigators operate.
Garmin 500 Glass for General Aviation Singles
The Garmin 500 provides a two-panel glass cockpit for a Primary Flight Display (PFD) and a Multifunction Display (MFD). The PFD replaces the six classic instruments: Airspeed, Attitude, Altitude, Turn, Heading, and Vertical Speed plus Course Deviation Indicators. This display features an Attitude Indicator (AI) and Horizontal Situation Indicator (HSI) that are 50 percent larger than traditional three-inch instruments.
An integral Attitude Heading Reference System (AHRS) replaces the mechanical gyros. To the left of the AI is an altitude tape and digital indicator. On the right is an airspeed tape and digital readout. Magenta trend vectors show where the altitude, airspeed and heading will be in six seconds. This makes interpreting tapes more intuitively similar to watching the dials in a round indicator approach the target altitude or airspeed.
The HSI is a great device integrating heading and navigation information in one display. They have been around for years as electromechanical units with all the inherent high maintenance costs. AHRS and microcode displays offer all the advantages with significantly reduced maintenance. To the HSI’s right is a vertical speed indicator that shows both analog and digital indications.
Synthetic vision is an option that shows terrain and obstacles in your flight path on the PFD. If the indicated flight path shows terrain in front of you, then it is time to change direction. Autopilots and Flight Directors drive displays through an optional adapter.
The MFD displays the flight plan track with waypoints, weather datalink NEXRAD and lightning in a larger display than the GTN or GNS displays. TIS, TCAS and ADS-B are optional traffic display inputs from other Garmin equipment. You can bring up either NACO or Jeppesen approach charts provided through an optional subscription service, navigate with the left screen PFD, then cross-check approach information displayed on the right screen. Land, and the MFD automatically transitions to the Safe Taxi display with your position shown on the taxi diagram.
If you want to see more pictures with explanations, go to the Garmin 500/600 tutorial link shown at the end of the article.
Upgrade Path
Let’s assume you have two Nav/Coms plus DME with an autopilot in your aircraft. How do you get from here to there? If you can write a big check, then go for it. You will enjoy the added situational awareness and safety, once you get the training to use all this equipment safely. If you’re like me, and you plan to get one piece at a time, then lay out your own program to fit your flying scenario.
You might start with an in-panel GPS navigator. ADS-B is coming in 2020 and ADS-B Out will be a new requirement. Even though it comes at the price of new equipment, there will be ease of flying and safety benefits with this requirement. Garmin’s solution requires a WAAS navigator plus a Mode S transponder with an Extended Squitter upgrade. I’ll bring you more ADS-B details in a future Avionics Bucket List article.
Second on my list would be satellite weather downlink or a glass panel. With a glass panel the second GPS navigator used primarily as an MFD becomes less important.
Handheld navigator units are tempting. They offer the same information but do not meet requirements for IFR navigation or an ADS-B interface. My recommendation is first to set the foundation with a known piece of avionics that will provide immediate benefits.
GNS 430/530 support will continue for some time in the future and offer a reasonable entry point. There are good used bargains or new units from Garmin available today. Our aircraft started with one GNS 430; that got us around in the IFR environment just fine.
If you currently have no GPS navigator in the panel, the GTN 450 is a good first choice. Why not start with the newest and the best for future feature enhancements? The user-friendly interface reduces pilot workload significantly and thus increases safety once you’ve completed a thorough equipment education program.
What about our wish list? The path is either to replace the GNS navigators with GTN navigators and stay with round gauges, or keep the GNS navigators and install a glass panel. With 12 years experience operating the older GNS equipment, increased situational awareness with glass seems to point toward glass as the number-one item on our bucket list.
Whatever you decide, looking at catalogs and touring the vendor buildings at AirVenture and other shows and deciding what your plan will be is a fun exercise. Go enjoy yourself and fly safe.
Charles Lloyd has logged 10,000 hours since his first flying lesson in 1954. He worked for Cessna Aircraft for 16 years, and retired as captain for a major fractional aircraft ownership company. His personal aircraft is a great business tool for his real estate investment company. Send questions or comments to editor@www.piperflyer.com.
Resources
Garmin GTN tutorials
https://www8.garmin.com/learningcenter/training/gtn/index.html
Garmin G500/G600 tutorial
https://www8.garmin.com/buzz/g600/
