When Switzerland’s Grob Aerospace launched its spn business jet at the 2005 Paris Air Show, one of the aircraft’s ground-breaking features was its adoption of Honeywell’s new Primus Apex avionic suite.
Designed to combine the performance and passenger comfort of a light business jet with the operational versatility of a turboprop, the Grob spn derives its name from the initials of its key attributes — superior performance, superb payload and single pilot capability among them — expressed to the nth degree. The Apex suite is behind the third of those characteristics, and the spn is set to be the largest private jet yet certified for single pilot operation.
The first spn prototype flew in July 2005. In May 2006, the manufacturer announced enhancements to the avionics system, which already featured the Traffic Alert Collision Avoidance System (TCAS) II, Enhanced Ground Proximity Warning System (EGPWS) and weather radar. Increased software processing power would allow for optional equipment such as an Enhanced Vision System (EVS) and such future options as auto-throttle, emergency descent mode and Electronic Flight Bag (EFB).
The second prototype flew in September 2006. The first spn to be equipped with the enhanced Apex cockpit, it crashed just two months later when parts of the elevators and horizontal stabilizer separated, possibly because of elevator flutter, during a demonstration flight at Grob’s Tussenhausen-Mattsies airfield in Germany, where the company’s manufacturing and assembly take place.
Flying resumed in February 2007 and a third prototype joined the flight test program last October. Certification was scheduled for the fourth quarter of this year.
‘Perfect Fit’
Ulrich Gehling, managing director of Grob Aerospace in Germany, said the selection of Honeywell’s Primus Apex cockpit was "a natural choice" as the avionics suite was "the perfect fit for the spn" in many respects. The Apex suite "combines the latest technology with unbeatable functionality and the highest level of integration and quality with a lot of capability for future growth," he said.
Gehling noted the system was designed specifically for single-pilot operation and based on the latest studies in human factors. "Through special human factors design criteria, both pilots with a general aviation background and professional pilots coming from large business and commercial aircraft will find it very easy and intuitive to adapt to Primus Apex," he said.
The system’s large, active matrix liquid crystal displays (AMLCD) "provide a sharp and crisp picture even in the most difficult sunlight conditions," Gehling said. "Their proven reliability is extremely high as they use technology developed for military applications operated in harsh environments."
Compared with previous generations of equipment, Gehling said, Primus Apex is a fully integrated avionics system. "It is no longer based on the installation of many individual point products, but on a centralized avionics suite," he said. "The four large AMLCDs offer a maximum of display real estate for easy interface with the pilot. And the hardware count is significantly reduced, improving reliability and therefore aircraft availability."
Operationally, the suite provides a maximum of transparency, situational awareness and functionality, Gehling said. For example, to dial in a radio frequency, the pilot has the choice of the more traditional way of radio selection using the bezel buttons on the display and frequency dialing on the Primary Flight Display controller, or alternatively using the modern alphanumeric key pad of the multifunction controller. The large displays allow the indication of all essential information and access to flight-typical functions without the complexity of having to walk through many levels of display menus.
"Again, the human factors aspects have always been a major driver in the system and pilot interface design," Gehling said.
As a derivative of the Primus family, and one based on the Primus Epic system used in larger business jets such as on the Dassault Falcon EASy flight deck, the Primus Apex offers a natural growth path, Gehling said.
"Honeywell is committed to integrating future Primus Epic system functionality into the Primus Apex system, such as the Integrated Primary Flight Display synthetic vision system," Gehling said, although schedules had not been finalized. Enhanced vision, too, will become available in the early phase of the suite’s introduction, while other functionality such as Automatic Dependent Surveillance-Broadcast (ADS-B), will be integrated into the Honeywell product family once a technology standard has been clearly established.
One of the Primus Apex features highlighted by Honeywell is the system’s integrated navigation (INAV) capability, offering what are claimed to be unparalleled views of weather, traffic and terrain for superior situational awareness and safety. The suite complies with current mandates such as Reduced Vertical Separation Minimum (RVSM) and enhanced Mode S diversity, and is fully upgradeable for future enhancements. It also provides multisensor Required Navigation Performance (RNP) capabilities for improved obstacle clearance, lower landing minimums, more "fly direct to" capability and reduced pilot workload.
The Primus Apex has a significantly reduced parts count than earlier generations. And the well established customer support network developed for the Honeywell Primus family will contribute to the spn’s high availability, according to Grob.
Grob also has selected Honeywell’s Ovation C Series cabin management system (CMS) and JetMap II moving map and information system for spn passengers. Ovation options include DVD/CD players, individual switch panels, XM Satellite Radio, MP3 connection and high-resolution LCDs, with either a 10.4-inch master cabin monitor mounted on the righthand forward bulkhead, or individual 8.4-inch "hot plug" monitors with individual control panels and headphone jacks for each passenger and up to four cabin speakers. JetMap II offers high resolution, worldwide maps, safety briefings and custom logos, along with live news, weather, business and sports content that will be uploadable via an optional Iridium satcom receiver.
Display Innovation
The displays used in the Primus Apex suite are provided by Belgium’s Barco under an agreement announced in October 2006. In Honeywell’s nomenclature, they are dubbed keyboard display units (KDU), and the Grob spn cockpit features two each of the 10-inch diagonal KDU-1080 and 15-inch KDU-1500.
Jean-Christophe Monfret, Barco’s product management director, said the Apex displays are derived from what Barco designates the FDU-2000 family of flight display units, which includes the 10-inch FDU-268 and 15-inch FDU-2129. The 10-inch display for the Apex suite has both FAA technical standard order (TSO) and European TSO (ETSO) airworthiness approval. The larger model gained ETSO approval at the end of February, with FAA approval expected within six-to-eight weeks. Both are certified to DO-178B software and DO-254 level A hardware standards, enabling them to be used as primary flight displays in combination with an external symbol generator.
The displays themselves use light emitting diode (LED) backlights and are very reliable, Monfret said, factors that combined with the price/performance ratio to help land the Honeywell order.
Barco’s involvement with Honeywell goes back to the early 1990s, when it supplied control display units (CDU) for the retrofit of Belgian Air Force C-130s. "Then we became their standard military CDU supplier," Monfret recalled.
The Belgian company has since provided CDUs for military platforms including the C-5, C-27J and C-130J, and since the "major breakthrough" with the Apex displays, Honeywell selected Barco to design and supply FDU-based displays as upgrades for CRT displays used with Honeywell’s Primus 1000, 2000, 2000XP, SPZ-8400, 8500 and SPZ-8000 avionics systems.
"Our strategy is to provide display solutions to system integrators," Monfret said, and being independent means "we can provide them different levels of solution. On Apex, we provide pure video displays, because they develop their own symbol generator hardware plus application."
Alternatively, Barco can provide smart displays incorporating its Modular Open System Architecture (MOSArt) middleware, which enables system integrators to add their own applications.
"That’s what we are doing in the U.K. with AgustaWestland on the Merlin (EH-101 helicopter) capability sustainment program," Monfret said. "We provide them a display with MOSArt and AgustaWestland is integrating its own application on top. And we can go even further. We can get an application from our customer and integrate it ourselves, or even develop some of the application ourselves and provide our customers with the integrated solution."
Barco applies the same ruggedization process used for its military displays to the commercial product ( Avionics, January 2007, p. 34). That involves buying commercial displays, then stripping out and ruggedizing the glass.
"It’s exactly the same process, even the same glass as in our military products," Monfret said. As a result, he said, "the display we provide for the Apex environment can actually survive much more than the light environment of a Part 23 aircraft. We can easily certify the display in a Part 25 aircraft."
Other Apex Applications
The same 10-inch displays used on the Grob spn feature in the Pilatus Next Generation PC-12E’s new Primus Apex cockpit, which recently won TSO approval from FAA.
In March 2007, Pilatus reported that during cold weather trials in Iqaluit, Canada, the new avionics and displays in particular had exceeded all the company’s expectations while experiencing extreme cold down to -10°F and below.
Honeywell’s Apex suite has also been selected by Harbin Aircraft Corp. of China for its twin-engine Y12 multipurpose aircraft.
New Embraer Bizjets
Embraer unveiled its new Midsize Jet (MSJ) and Midlight Jet (MLJ) at an April 8 event in Washington, D.C. The twinjets are expected to enter service in 2012 and 2013, respectively.
Both aircraft will be equipped with the Rockwell Collins Pro Line Fusion integrated avionics suite, with four 15-inch LCDs and standard Synthetic Vision. They will be fly-by-wire, with sidestick pilot controls.
Honeywell is supplying HTF7500E engines, nacelles and thrust reversers.