Gap narrows between two super-midsize contenders

 - November 27, 2007, 6:24 AM

With the Raytheon Hawker Horizon and Bombardier Continental making their first flights within three days of each other in Wichita last month, development is virtually neck and neck for these two highly competitive super-midsize business jets.

Raytheon Aircraft’s largest airplane, the Horizon made its maiden flight on Saturday, August 11, more than a year behind its original schedule. Powered by two P&WC PW308A turbofans, the airplane flew a 2.5-hr mission from Wichita Beech Field that tested the aircraft’s flying qualities, engine operation, low-speed handling and climb performance. The Horizon reached an altitude of 10,500 ft msl and a speed of 225 kt.

Four aircraft will participate in certification testing, which is expected to be completed in 2003. Raytheon said it holds orders for more than 150 Horizons, including options; 100 of them are destined for Executive Jet’s NetJets fractional aircraft-ownership program. That order–50 firm and 50 options–was made at Paris 1999, with deliveries originally expected to begin next year.

After the flight, test pilot Tom Carr noted, “The aircraft was everything we expected and more. Performance and handling qualities were exactly as expected. Controls were very responsive and predictable.”

Raytheon selected the Honeywell Primus Epic system as the standard avionics for the Horizon. The system features five 8- by 10-in. active matrix liquid crystal displays and includes an integrated performance computer in the FMS coupled to a full-authority autothrottle.

Continental Airborne
On August 14, just three days after the Horizon flight, Bombardier test pilots flew the Continental for the first time from the Learjet facilities at Wichita Mid-Continent Airport. During the two-hour flight, the Honeywell AS907-powered business jet reached an altitude of 17,500 ft msl and a speed of 210 kt.

The initial test flight investigated basic maneuverability, engine handling, aircraft stability and general flying qualities, as well as various systems. Jim Dywer, Continental test pilot, described the flight as “very successful. The aircraft performed extremely well, exhibiting solid performance and mature systems reliability.
Bombardier said five aircraft will take part in certification flight testing, four of which are to enter the test program this year. As of June, 115 Continentals have been ordered, according to Montreal-based Bombardier. The company said the Continental is on schedule to obtain certification in the third quarter of next year.

Before takeoff, the Continental’s engines were run at climb power for five minutes. The engines were then advanced to takeoff power and held there for 30 sec before brake release. At 4,000 ft msl, the throttles were reduced to climb power and the aircraft continued to 10,000 ft. Power was then reduced to 75 percent N1 while numerous checks were completed. Normal thrust-reverser deployment and stow were used on the landing. The AS907 engines and thrust reversers are part of the integrated propulsion system Honeywell is providing for the Continental.

“The engines operated flawlessly throughout the flight and met all performance and handling requirements of the test program,” said Mike Redenbaugh, vice president and general manager of the AS900 program. Certification for the AS907 business jet engine is expected in the second quarter of next year. Honeywell planned to certify the engine in March, but development has been delayed because more time is required to incorporate engine core changes that are designed to improve durability and maintainability of the powerplants.

The Honeywell AS900 series has accumulated more than 9,500 hr of engine testing, including 550 flight test hours on Honeywell’s Boeing 720 and more than 500 flight hours on the Avro RJX regional jet. The AS907 has a takeoff rating of 6,672 lb of thrust at ISA+15 for the Continental and is configured with a 34.2-in. fan and a bypass ratio of 4.2:1.

The Rockwell Collins Pro Line 21 is the standard avionics suite on the Continental. The flight-deck layout includes four 12- by 10-in. liquid crystal flight displays, consolidated      control panels, TCAS II and TAWS.

The Collins suite includes an EICAS to monitor, analyze and display performance of aircraft engines and other onboard systems. Linkage of EICAS monitoring capabilities to the aircraft’s maintenance diagnostic computer permits aircraft systems performance and maintenance data to be sorted, logged and analyzed.

Although the schedules of the two airplanes are now close, that was not always the case. The Horizon was introduced at the 1996 NBAA Convention and originally projected to make its first flight in late 1999. Had the Horizon adhered to its original schedule, it would have received certification this past spring. The Continental was officially launched at the 1999 Paris Air Show and remains very close to its originally projected timetable–its first flight was initially projected to occur two months ago.

While the Continental and Horizon are similar in performance and specifications–both aircraft are designed to have six- to eight-passenger NBAA IFR ranges of between 3,100- and 3,400 nm at speeds between 0.78 and 0.80 Mach–they are strikingly different in how they are manufactured. The Continental’s fuselage is aluminum, while the Horizon’s is composite. Raytheon’s composite assembly process promises eventually to significantly reduce the cost of manufacturing. Bombardier’s Continental retails for $14.675 million compared with $16.9 million for the Horizon.
For a detailed comparison of the preliminary performance and specifications of the Continental and the Horizon, see the “New Business Aircraft Report” on page 20.