Military


CL-600 Canadair Challenger

The CL-600 Canadair Challenger is the business jet from which the Canadair Regional Jet was derived. The three models in the CL-600-2B19 series are the Canadair Regional Jet CRJ-200 model, the CRJ-100 and CRJ-440.

The Canadair Challenger is a high-speed, long range airplane designed for the business jet market of the 1980s and 1990s; it is an all new aircraft that incorporates advanced airfoil technology, high by-pass ratio fan engines, advanced materials, advanced systems and a wide body fuselage to provide interior cabin space consistent with the long range capability.

The Canadair Challenger began as a project for an advanced-technology bizjet by William Lear, developer of the Learjet. It was then called the Lear Star 600. Canadair Limited purchased the production rights from Lear, renamed the aircraft the Challenger and began production of the prototype in 1976. The latest high-bypass turbofan engines power it. The engines (Avco Lycoming ALF 502) produce 7,500 pounds of thrust, giving the 40,000-pound aircraft the highest thrust for its weight of any bizjet. These innovations allowed this aircraft to takeoff quicker, climb faster, fly farther and have better fuel efficiency than any aircraft in its class.

The Challenger was the first production aircraft to use supercritical wings. This airfoil, considered unconventional when tested in the early 1970s by NASA at the Dryden Flight Research Center, is now universally recognized by the aviation industry as a wing design that increases flying efficiency and helps lower fuel costs. Called the supercritical airfoil, the design has led to development of the supercritical wings (SCW) now used worldwide on business jets, airliners and transports, and numerous military aircraft. Conventional wings are rounded on top and flat on the bottom. The SCW is flatter on the top, rounded on the bottom, and the upper trailing edge is accented with a downward curve to restore lift lost by flattening the upper surface.

During the early 1970s, a major breakthrough in transonic aerodynamics was achieved at NASA -- the supercritical wing. The transonic regime had beguiled aerodynamicists for years. At transonic speeds, both subsonic and supersonic flow patterns encased an aircraft. As the flow patterns went supersonic, shock waves flitted across the wings, resulting in a sharp rise in drag. With most commercial jet airliners operating in the transonic range, coping with this drag factor could bring major improvements in cruise performance and yield substantial benefits in operating costs.

In the 1950s, NASA reseracher Richard Whitcomb created the area rule (wasp waist) design that gave supersonic aircraft the "pinched look" to reduce aerodynamic drag and increase transonic speed without added power. During the 1960s, Whitcomb had committed himself to a program intended to resolve the transonic problem. For several years, Whitcomb intensely analyzed what came to be called the "supercritical" Mach number--the point where the airflow over the wing went supersonic, with a resultant decline in drag. Analysis and wind tunnel tests led to a wing with a flattened top surface (to reduce its tendency to generate shock waves) and a downward curve at the trailing edge (to help restore lift lost from the flattened top). But wind tunnel tests were one thing. Real planes in the air were often something else. The next step meant thorough flight testing of a plane equipped with the unusual wing.

Fortunately, NASA came up with an available plane that lent itself to comparatively easy modification: the Vought F-8A Crusader. The structure of the plane's shoulder-mounted wing made it easy to remove and replace with the supercritical design. Moreover, the F-8A was built with landing gear that retracted into the fuselage, leaving the experimental wing with no outstanding production encumbrances. The Navy had spare planes available, and its speed of Mach 1.7 made it ideal for transonic flight tests. Although the test plane had begun life as a Navy fighter, the supercritical wing program was aimed at civil applications. The airlines as well as the airline manufacturers closely followed development of the new airfoil. The modified Crusader, designated the TF-8A, made its first flight at Edwards in 1971 and continued for the next two years. The test flights yielded data that corresponded to measurements from the preliminary tunnel tests at Langley.

The supercritical wing promised genuine improvement in the transonic region, a fact that translated directly into reduced fuel costs and lower operational costs. Ironically, foreign manufacturers of business jets were the first to apply the new technology in new designs like the Canadair Challenger (Canada) and the Dassault Falcon (France).

But the first aircraft crashed in a deep stall accident. On April 3, 1980, a Canadair Limited CL-600 was destroyed during stall testing near California City, California. The pilot was killed, and the copilot received minor injuries. The flight test engineer was not injured. According to statements from the surviving pilot and flight test engineer, the flight crew was troubleshooting a noise associated with stalls conducted during previous flight test activities. Airplane control was lost during the stall, and the emergency spin recovery parachute was deployed. According to the copilot and flight test engineer, who were able to bail out, attempts to jettison the parachute were not successful and airplane control was never recovered.

While certification was granted in August 1980, temporary restrictions limited maximum takeoff weight to 14,970kg (33,000lb) and maximum speed to 587km/h (317kt), with flight into known icing conditions and the use of thrust reversers prohibited. Production of the 600 ceased in 1983, having switched to the much improved 601.

Challenger 601

A major weight and drag reduction program pared back the Challenger's weight, improving range. The addition of General Electric CF-34 turbofans as options to the Challenger 601, further addressed performance shortfalls and overcame problems with the ALF-502 turbofan. The Challenger 601 addressed the original CL-600 Challenger's weight problems and replaced the troubled ALF-502 turbofans, creating a highly successful full size corporate jet. The 601 first flew on 10 April 1982 and for a time was offered alongside the 600. The 600 was dropped from the model line in 1983.

Challenger 604

Further improvements to the basic design led to the Challenger 604. Improvements include an advanced Collins ProLine IV EFIS avionics system with color displays, higher weights, CF-34-3B turbofans and increased fuel tankage. Many other minor changes were incorporated based on Bombardier's experience with the Canadair Regional Jet. First flight with CF-34-3A engines was in September 1994, first flight with the CF-34-3B engines was on 17 March 1995, with Transport Canada certification granted that September. First delivery was in January 1996.

The spacious Challenger 604 became the world's best-selling large corporate jet due to its mission versatility, supreme comfort, and cost efficiency. At its introduction, the Challenger 604 set new standards in general aviation for comfort, low cabin noise levels, and unprecedented cabin space. The CL 604 offered the opportunity to fly one of the most luxurious business jets available in the country. The Challenger 604 makes lengthy trips comfortable and enjoyable with room for 9 to 10 passengers. Amenities include a full service galley, large comfortable leather seating, in-flight accessible baggage and a spacious private lavatory.

Challenger 605

The newly redesigned Challenger 605 is the next major step in the evolution of the Bombardier Challenger business jet family. Equipped with a new avionics suite, more ample interior and larger, higher windows for more light and better viewing, the Challenger 605 flies coast to coast and internationally more comfortably than ever before. At the touch of a button, access the cutting-edge cabin entertainment system, including XM Radio, enhanced AIRBORNETM Office, DIRECTVTM and audio/video-on-demand. The newest Challenger elevates the benchmarks of business productivity, comfort, reliability, value and versatility. The newly designed cabin of the Challenger 605 accommodates up to 12 passengers, with plenty of room to recline and stretch out. Walk through the stand-up cabin with ease.





NEWSLETTER
Join the GlobalSecurity.org mailing list