Lanseria based avionics specialist Aeronautical Aviation has just completed its first upgrade of a Pilatus PC-12 to the latest Garmin G600TXi and GFC600 suite. This brings the older PC-12 up to date yet saves millions of dollars on the cost of a new PC-12 NGX.

Upgrading the PC12-45 to a Garmin 600 brings the aircraft up to date and makes it safer – for far less cost than a newer model.

GARMIN AND PILATUS received a Supplemental Type Certificate (STC) to install the Garmin G600TXi avionics system in all pre-NG PC-12s, that is, those produced between 1994 and 2008. A key improvement is the integration of the Garmin GFC600 autopilot. Aeronautical Aviation is leading the way, being one of the first in the world to successfully integrate the GFC600 into the PC-12.

Improved Safety

The GFC600 is for many the gold standard in autopilots – especially when integrated with the huge capability of the whole Garmin avionics suite.

Key abilities of the GFC600 autopilot are its ability to fly coupled approaches (but not full Autoland) and the many other benefits that spin off from this. This includes the invaluable safety aid of an emergency auto descent system. If the system detects a loss of cabin pressure it emits a loud aural warning for a minute. If there is no response from the pilots the emergency descent system engages and immediately turns the aircraft left 90 degrees to exit the airway and start an emergency descent. It switches the autopilot to Indicated Airspeed Mode, pushes the nose down and pegs the speed at Vne less 10 knots. It then automatically levels out at 15,000 feet, a naturally breathable altitude.

It also considers the terrain, should the MSA be higher than 15,000 ft.

With the G600 installation the aircraft gains many new operational capabilities including coupled VNAV descents and fully coupled missed approaches, as well as Garmin’s ‘Smart Glide’ which can automatically pitch the nose angle for the aircraft’s best glide speed while simultaneously navigating within the vicinity of the selected airport so the pilot can execute an approach and landing.

The installation of modern avionics enables the pilots to use the increasingly common GNSS approaches, plus it reduces pilot workload and improves situational awareness.


The GFC also provides lifesaving flight envelope protection – on par with the most modern Airbus airliners. Garmin calls this Electronic Stability Protection (ESP) and it includes a stick shaker plus protection against stall and excess pitch and bank angles.

A key factor in making decisions in avionics investments is maintenance, especially in the light of the current semi-conductor shortage, as the support for the original Honeywell avionics may become limited due to parts availability and supply chain issues. Being the most modern state-of-the-art system, the G600Txi installation can be expected to be well supported and updated for a lengthy period.

The original PC12-45 panel is busy, heavy and has limited functionality.

In the Cockpit

The Garmin G600TXi New Perspective for the PC-12 combines both the primary flight display (PFD) and the multi-function display (MFD) into a single 10-inch wide flat-panel LCD screen that is readable in direct sunlight and has touch screen controls.

The G600TXi comes with a large menu of valuable standard features. Key amongst these are: Garmin SVT Synthetic Vision Technology, TAWS-B terrain alerting, FliteCharts and SafeTaxi.

The G600TXi comes standard with full colour 3D synthetic vision. For added situational awareness and to get the aircraft certified for GNSS approaches there is an optional Terrain Warning (TAWS B) function. Instead of gyros with high maintenance moving parts, the G600TXi uses the solid-state GRS77 attitude and heading reference system (AHRS). As a key safety feature, the installation displays the PC-12’s angle-of-attack on the G600TXi PFD.

Optional inputs make it possible to overlay onboard radar, traffic alerts, XM satellite weather (for the USA) and other inputs such as Satphones. Support for an optional radar altimeter control/display is provided and there’s also a video input option that enables the G600TXi MFD to function as a live-cam video monitor. A popular option is to unlock the Chartview on the G600TXi, which with a Jeppesen charts subscription, gives the pilot the capability to fly precision Required Navigation Performance (RNP) approaches with augmented GPS accuracy.

The complete G600TXi New Perspective system also includes the Garmin GI 275 Electronic Standby Instrument, making the PC-12’s panel a low maintenance, full-glass, setup.


In South Africa, Aeronautical Aviation has just completed its first PC-12 upgrade, to a 2003 PC-12/45, ZS-MSF. The CEO of Aeronautical Aviation, Clinton Carroll said, “Upgrading the older PC-12s to modern Garmin avionics is an unbeatable proposition. The aircraft’s capability is much improved, particularly its ability to meet the standards of GNSS-RNP approaches, plus have the legally required updates such as ADS-B in and out.”

Clinton continues, “The new G600TXi installation transforms the capability of older PC-12s, bringing them to a level comparable with the latest PC-12 NGX that costs many millions of Dollars more. Yet we can upgrade older PC-12s with our labour and other inputs denominated in South African Rands and this means the owner gets a Dollar based improvement paid for in Rands,” he says.


“The older PC-12s are approaching thirty years of age and eventually the question will arise as to their support by the original avionics manufacturers. While support for the original Honeywell avionics is still good, over time it is natural that it may take longer to obtain parts. In addition, the new features and ease of use of modern avionics make this upgrade a no-brainer. It’s like comparing a 20 year old Nokia 5110 1998 cellphone to a modern smart phone,” Clinton says.

This is just a tantalising taster to what can be accomplished with the modern Garmin suite. An STC that is being eagerly awaited is the expanded engine monitoring capability with the TXi Engine Indication System (EIS) display. This upgrade offers a complete package that includes the G600 TXi flight displays, GTN Xi Series navigators and a GI 275 electronic flight instrument configured as a standby flight instrument.  

A key advantage of the upgrade is that it removes legacy avionics and wiring, creating weight savings. Other optional upgrades include an audio panel, ADS-B transponder, Iridium datalink, weather radar, datalink SiriusXM weather, and for the cabin as well as the cockpit, Garmin Connext connectivity via the Flight Stream 510 wireless gateway.

Another popular option that is both simple and inexpensive is the MD93 USB charger/clock so that the pilots can charge their iPads and smartphones during flight.

Cost and Downtime

So what does it all cost, and how much downtime will there be? Clinton Carroll explains that a typical cost could be budgeted between R2.5 to R4 million, depending on options. “The integration of the GFC600 autopilot has been a steep learning curve as it integrates with many of the aircraft systems and thus has many complex relays. This is one of the first such installations in the world and Garmin and Pilatus worked closely with us to make it all come together. The downtime for the ZS-MSF upgrade was just 3-months and I reckon I can get it down to two months, now that the initial steep learning curve has been accomplished,” Clinton explains.

Pilatus fully supports the STC upgrade. When it was announced, Thomas Bosshard, the CEO of Pilatus, said; “We were looking for a way to enable legacy PC-12 owners to realise continued value in their PC-12 investment. With the Garmin G600TXi avionics suite they will be able to update their aircraft with many of the features available in today’s aircraft and lower their ongoing maintenance costs. It is one of the many ways Pilatus strives to support our customers above and beyond the initial sale.”

Upgrading the PC-12 requires extensive gutting of the interior fittings and the entire instrument panel.

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