The addition of the Honeywell Primus Apex integrated avionics system to the NG version of the venerable Pilatus PC-12 turboprop single has made an already solid airplane even better. 

Derived from technology originally developed for Honeywell’s Primus Epic cockpit in business jets and turbine helicopters, Primus Apex in the PC-12 has been honed by Pilatus test pilots for the unique demands of single-pilot operations and VFR flying–neither of which was a high priority when Honeywell was developing the Gulfstream PlaneView and Dassault EASy versions of Primus Epic.

Primus Apex in the PC-12NG is reminiscent of these higher-end business jet cockpits, particularly in the case of the EASy flight deck, which uses the same T display arrangement, with primary flight displays placed in front of the pilots and multifunction screens stacked in the center of the cockpit. The Apex displays in the PC-12NG are smaller than those in the Dassault EASy-equipped airplanes (10.4 inches diagonal versus 14 inches), but at a glance the cockpits look strikingly similar.

Apart from appearance, though, the Primus Apex cockpit stands on its own merits. The engine and avionics startup procedures in the PC-12NG have been greatly simplified, as has the presentation of information to the pilot. Displays are partitioned into 2/3, 1/3 and 1/6 windows with “aviate,” “navigate” and “communicate” functions clearly segregated by individual window. Information is presented to the pilot by phase of flight, a design philosophy that Honeywell says reduces workload by providing a more intuitive presentation of data.

SimCom, which has a PC-12NG flight-training device at its Orlando, Fla. center, is offering initial and recurrent training in the PC-12NG, with the initial course still lasting just six days. But the changes between the old PC-12 and new are significant enough that a pilot transitioning to the cockpit would be well advised to fly 50 or so hours with the system before venturing into hard IFR conditions single pilot. 

When the Apex flight deck was first introduced in the PC-12NG two years ago, some pilots were disappointed to find that key features promised by Pilatus–electronic charts and XM weather being two examples–were left out of Apex. But an ever evolving series of software and hardware updates has added these and nearly all the other capabilities pilots were asking for, with a few remaining wish-list items scheduled for introduction in the coming months. 

Coming in the next software revision, known as Build 7, will be graphical presentation of airspace boundaries on the iNav moving map and vertical guide path presented on the vertical map. Also in the works are an option for a second flight-management system, video interface for displaying enhanced-vision imagery on the MFD and Rnav approach glidepath coupling. At press time Honeywell was working toward certification of its own Waas-capable receiver, which will be included as standard equipment in the Build 7 cockpit.

Another minor complaint among PC-12NG pilots has centered around the original joystick-style cursor control device (CCD), which at times made accessing Apex’s drop-down menus a chore. The recent addition of an improved trackball CCD on the pedestal between the seats adds one of the last remaining major elements to a cockpit that Honeywell clearly intends to be a slicker alternative to avionics systems from competitors Garmin and Avidyne, which dominate the lower end of the GA avionics market. The new CCD system features an ergonomic palm rest with a conveniently positioned trackball, scroll wheel and buttons for making selections on the two large Apex multifunction displays. 

A question buyers of the $4.375 million PC-12NG invariably ask is when Pilatus and Honeywell plan to bring synthetic vision to the airplane. Honeywell has released images showing an SVS view on the Apex PFD that includes vertical airspeed and altitude tapes on the sides, HUD-style flight director cues in the center and an arc-style horizontal situation indicator on the lower portion of the screen. While no official word has been given, Pilatus officials hint that Honeywell’s SmartView SVS is coming to the PC-12NG soon, with an announcement perhaps being held to coincide with the NBAA Convention this fall.

Apex in the Air

Pilatus rolled out the 1,000th PC-12 built at its Stans, Switzerland factory last month. Since its certification in 1994, this remarkably successful airplane has been known for its tremendous flexibility and utility. The addition of a thoroughly modern cockpit to an airplane that at times seems to do the impossible could be just the thing to coax another thousand PC-12 buyers to step forward.

A recent demonstration flight in a PC-12NG fitted with the latest Build 7 cockpit improvements highlighted what a capable and intuitive system Apex really is. Pilatus was the launch customer for the first Apex application delivered in 2008. Honeywell then delivered the first Primus Apex upgrade, known as Build 5, with added features that included Jeppesen electronic charts and XM weather. Build 6 added vertical glidepath coupling for airplanes equipped with the optional CMC Electronics Waas-capable GPS.

The PC-12NG’s primary flight display gives the pilot all the information he needs to fly the airplane, including readouts of critical engine data in the top right third of the display and nav and com frequencies on the lower right third. The top MFD in the middle of the cockpit includes the complete flight plan in a partitioned window next to a moving-map window that can be accessed with the cursor. Flight-planned routes can be amended using the FMS keyboard or by clicking on the planned route on the display and dragging it to a new waypoint. 

Pilots can use the feature, known as “rubber-banding,” to change their route of flight or alter course to avoid weather. The point-and-click and point-and-drag commands accessible with the CCD allow pilots to input holds, intercepts, amended routes and new waypoints with ease. Clicking the CCD calls up a variety of menus that the pilot can scroll through to accomplish a compendium of tasks. So integral is the CCD to the operation of the Apex system that a crew would be lost without it, said a pilot for PlaneSense, a New Hampshire-based fractional operator that flies an all-PC-12 fleet. 

The lower MFD can be used to call up electronic charts and a variety of flight-related information, all accessible through intuitive drop-down menus that are similar in look and feel to those included in Gulfstreams and Falcons fitted with Primus Epic. One nice touch in the PC-12NG is the inclusion of simultaneous map and vertical profile views of electronic charts, obviating the need to pan and zoom to see different sections of the chart. Paperless capabilities in Apex are directly linked with the FMS. 

Almost lost among all the talk about the new avionics in the PC-12NG are the additional improvements over its predecessor, including the completely new cockpit layout designed by BMW Group DesignworksUSA and a more powerful Pratt & Whitney Canada PT6A engine. The Next Generation PC-12’s advanced systems also include a digital dual-zone environmental control system and automatic digital cabin pressurization. Higher performance comes from the P&WC PT6A-67P turbine engine, which delivers 15 percent more thermodynamic power for faster climbs and higher cruise speeds.