Getting Development Back on Track
Now the onus is on in Brazil to forge ahead in the next several months with a 2,000-hr. flight test campaign that's required for earning type certification by the end of 2013 or beginning of 2014.
Learning from the Phenom 100/300 development program, Embraer built a complete Legacy 450/500 engineering office at its Gavião Peixoto flight test facility that will accommodate 200 engineers from Embraer and its program partners who will work side by side with test pilots during the flight test campaign to expedite development work. The team will include systems, powerplant, avionics, interior and manufacturing engineers, plus supply chain specialists.
“Everything will be there. I think this is a very good approach. So, the engineers will be very close to the flight test campaign, very close,” says Marco Tulio Pelligrini, Embraer Executive Jets COO.
Two prototype and two fully production conforming aircraft will be used for the flight test campaign. The first two aircraft will be fitted with full flight test instrumentation and used primarily for envelope expansion and performance evaluation. The second prototype is slated to fly “as soon as it can” after the first prototype takes flight, perhaps “a matter of weeks,” says Ricardo Maltez, Legacy 450/500 program manager.
The third aircraft, fitted with all production systems including the interior, is slated to fly by year-end. It has been used for high-intensity radiated fields (HIRF) and lightning tests. The fourth aircraft — “the actual finished article,” says Edwards — will undergo hundreds of hours of function and reliability proving, including multiple takeoffs and landings, to assure a smooth entry into service in 2014. Edwards said the goal is to wrap up all the lessons learned from the first three flight test aircraft into the fourth, so that engineers can wring out as many problems before production aircraft are delivered to customers. The fourth aircraft is slated to start flying in the second half of 2103.
“We learned a lot from the Phenom, the first airplane we designed for the market. Maturity plays a very important role in the game, so we learned from the entry into service of the Phenoms. We had some 'spots' as you know,” says Tulio Pelligrini.
“[For the Legacy 450/500,] we created a dedicated team, a broader team with our suppliers. And we've run lots and lots of tests, much earlier than we did with the Phenom 100,” he continued. “We did HALT [highly accelerated life testing] to monitor the quality and the assurance of the components. In terms of the interior, we built an actual interior and installed it in a real fuselage and then 'flew' it. We took maybe 300 or 400 people to Brazil, including salespeople and customers, and we spent hours aboard the mock-up. They had lunch there, they had dinner there, people slept on the airplane. We even used the lavs. So, we've had the chance to learn before we start delivering airplanes to customers.”
“We don't see any major challenge. It's just getting it done. We've certified fly-by-wire airplanes before and it is a big step forward, but we are very comfortable with the control laws,” adds Maltez.
“One of the key aspects is maturity,” Maltez continued, “something we're taking very seriously, both on product support and the factory itself. As a real example, we just finalized our lightning and HIRF ground tests. We'll have one and a half to two years before entry into service to correct what we find. Typically, in the past, we would do those tests later on in the flight test program. So, this is maturity. We're catching those [problems] right now.”
Embraer took full advantage of the lull time in 2011 and 2012 to work on other parts of the aircraft, as well. “Iron bird” avionics, systems and interior mock-ups have been used to mature components in preparation for entry into service.
“While we waited for first flight, we haven't been idle at all,” Edwards comments. “The fourth airplane will gain maturity on the interior and all the systems even while the certification process is going on. So, the aircraft will be ready for entry into service on Day One, rather than entering into service and then maturing.”
Weight control will be critical to attaining Embraer's performance goals for the airplane, including the Legacy 500's ability to fly four passengers 3,000 nm at Mach 0.80 and landing with 200-nm NBAA IFR reserves. Such range makes possible flying nonstop from New York to London; Los Angeles to Kahului, Hawaii; Toluca, Mexico, to Gander; and Paris to Abu Dhabi.
It also will be able to fly eight passengers more than 2,800 nm and land with the same reserves, so it will be able to fly a 1,600-lb. payload from Los Angeles to New York, Delhi to Beijing, or Kuala Lumpur to Tokyo. Range with the maximum payload of 2,800 lb. will be more than 2,500 nm. Up to 11 passengers and one flight attendant can be seated in the cabin, so payload capacity shouldn't be an issue.
Embraer also predicts the airplane will have a 4,600-ft. TOFL and a 2,400-ft. landing distance assuming sea level ISA conditions. It will be able to climb to an initial cruise altitude of 43,000 ft. in 22 min. Maximum cruise altitude will be 45,000 ft. while the aircraft maintains a 6,000-ft. cabin altitude.
“So far, wind tunnel tests tell us we are doing just fine,” says Edwards.
But meeting weight targets is key to attaining such performance goals. While Embraer declines to discuss target weights for the aircraft, Maltez is confident about weight control. “Weight is always an issue in every development [program]. I don't know any [program] where we didn't find challenges. But we are very, very close to our targets, in the range of 1%.”
Keeping the interior completion weight under control is just as important. Austrian firms Fischer Advanced Composite Components and List Group are supplying the interior and Maltez says that “weight is not an issue.”
Performance, weight and high reliability are utmost goals. “This program needs to be right out of the box,” says Edwards.