Technical hurdles delay Primus Epic program
Ongoing software integration problems are forcing at least two airframe manufacturers into the unenviable position of having to stretch aircraft certification schedules to give Honeywell engineers time to troubleshoot a variety of technical issues that are manifesting themselves in the Primus Epic avionics system.
In development for the past seven years, Primus Epic is the all-glass integrated avionics platform selected by manufacturers for a number of emerging aircraft programs, including the Dassault Falcon 900EX with Primus Epic EASy avionics and the fly-by-wire Embraer 170 regional jet, both of which will be delayed by several months to accommodate needed software changes and additional flight testing, according to the manufacturers. Other in-development aircraft that fly with Primus Epic are the Gulfstream G550, Bell/Agusta AB139, Cessna Citation Sovereign and Raytheon Hawker Horizon.
While offering a variety of technical reasons why the delays are occurring, Honeywell nevertheless accepted much of the responsibility for the schedule slippages. According to Vicki Panhuise, Honeywell vice president of programs, Primus Epic has required unprecedented levels of integration between aircraft systems and avionics. This, she said, has presented an ongoing challenge for the avionics manufacturer’s engineering staff, as well as the FAA, component suppliers and airframe builders. Early on Honeywell was very successful with Primus Epic, selling airframe OEMs on the system’s modular avionics concept and advanced features. At the time, said Panhuise, the aviation industry was in a steep growth mode and it was difficult for Honeywell to find engineers with the expertise necessary to shepherd Primus Epic through what in the end turned out to be no fewer than six concurrent certification programs.
“So we got behind,” said Panhuise. “And as people here got behind, flight testing got behind. It is unfortunately a reality of aircraft certification. We spent a lot of time working with our customers on the fact that we were having difficulties finding experienced resources during the market growth period and that this was causing a bubble of work that we had to manage.”
In Dassault’s case, software debugging will now require additional testing through the summer to make sure the avionics and aircraft systems are compatible. The delay means U.S. certification of the EASy-equipped Falcon 900EX will probably slip to late October or early November, according to company officials.
“Current delays in getting EASy certified are due to longer-than-expected integration by Honeywell of our software into Primus Epic,” said Jean-François Georges, Dassault senior vice president for civil aircraft. “Some bugs can still be found today, and we need to get rid of all of them before entry into service.”
According to the original development schedule from Dassault, the Falcon 900EX with the EASy cockpit was supposed to have been certified by now. A spokesman for Dassault Falcon Jet said early customers have so far been understanding of the delay, adding that once the software issues are fixed production can be ramped up quickly to put the airframe manufacturer back on schedule.
A spokesman for Gulfstream in Savannah, Ga., conversely, said flight testing of the G550 has been completed and that necessary certification paperwork was still expected to be submitted to the FAA by the end of last month. He added that Gulfstream is sticking to its original projection that full type certification of the ultra-long-range business jet will be in hand by the end of the third quarter (Gulfstream received provisional certification for the G550 last December). The spokesman added that the company took seriously warnings from Honeywell that the avionics testing could take more effort and time than originally thought and directed its resources accordingly.
Hints of trouble with Primus Epic first surfaced publicly at June’s Paris Air Show, when Embraer CEO Mauricio Botelho told reporters that U.S. type certification of the Embraer 170 would be delayed until November, several months after the first airplanes were promised to launch customer Alitalia. Botelho blamed the difficulties on integration of the 170’s fly-by-wire flight controls with Primus Epic software. Panhuise said Honeywell is now in the midst of “a tremendous effort” to rectify issues with OEM customers, which has included new software loads for the Embraer avionics test airplane at Honeywell’s aerospace headquarters in Phoenix.
The other certification programs that include Primus Epic will need to make adjustments, but schedules are anticipated to hold firm for business jet OEMs. Additional flight testing of the Citation Sovereign and Hawker Horizon will be required, but the manufacturers say they are maintaining their current time schedules that these airplanes will be certified as previously announced (by the end of the fourth quarter for the Sovereign and next year for the Horizon). The Bell/Agusta Aerospace AB139 medium-twin helicopter, meanwhile, is anticipated to experience a delay in gaining its U.S. certification (Italian authorities signed off on the AB139 in June), but this apparently has more to do with the FAA’s requiring a new cockpit layout than with software-integration issues.
As an example of the types of hurdles Honeywell engineers have faced with Primus Epic, Panhuise pointed to the system’s novel modular avionics unit (MAU), the integrated cabinet that houses a variety of components including power supply and input/output controllers, as well as integrated utilities developed by third-party suppliers. When Honeywell started the development program no one had ever certified an MAU. There were no regulations or TSO standards to follow and so Honeywell had to start from square one, working with the FAA and JAA to set the standards for what an MAU would be.
Honeywell finally gained TSO approval to new c153 standards at the end of last year, leaving precious little time to integrate the MAU with the rest of the avionics and make sure all the components would work together, said Panhuise.
“We are plowing new ground here,” she concluded. “It’s new for Honeywell. It’s new for our customers. It’s new for the certification authorities. And it’s new for pilots. And so you put all those things together and you’re bound to have some areas that are disconnects that you have to go solve, and that takes time.”