The Boeing 717

ME.

Following its lineage until the DC-9, the MD-80 and the MD-90, the Boeing 717, which had initially been designated as the MD-95, had been the last purely McDonnell-Douglas aircraft and the first and only in been transferred to Boeing to continue production.

Conceived as an advanced, low-wing, 100-passenger airliner with two high-ratio bypass turbofan mounted on the stern and a T-tail more closely based on the MD-90, its immediate predecessor, the design, designed to high frequency, However, short to medium range routes had inherently incorporated the 40-year development story of their previous generation family. Having carried the three names of Douglas manufacturer, McDonnell-Douglas and Boeing, the basic fuselage had presented three wings; three motor cores: Pratt and Whitney JT8D, International Aero Engine V2500 and BMW Rolls Royce BR715; a wide range of thrust capacities, from 12,000 to 25,000 pounds; four basic designations: DC-9, MD-80, MD-90 and MD-95/717; passenger capacities that vary between 90 and 180 in single class arrangements; and eight fuselage lengths, such as DC-9-10, DC-9-30, DC-9-40, DC-9-50, MD-80, MD-87, MD-90 and 717

Designed as a next-generation DC-9-30 replacement, numerically the most popular DC-9 version with 662 that was sold, the originally designated MD-95 has a total length of 124 feet, which is 1.7 feet shorter than that of the DC-9-40, which allows a complement of 106 passengers in a first-class four-seat, two, two, with a 36-inch seat and an economical five-seat, two, three, 32-inch pitch of the seat. One hundred and seventeen can be accommodated alternately in a single class configuration and five a day. Two warehouses under the floor facilitate the storage of luggage, cargo and mail.

The cabin for two people of last generation is equipped with six interchangeable units of liquid crystal display (LCD), an electronic instrument system (EIS), a dual flight management system (FMS), a fault display system control (CFDS)), and an advanced Honeywell VIA 2000 computer, and is capable of category IIIA landings, with provision for minimum minimum IIIB operations.

Its all-metal wing with two stringers, like that of the previous DC-9, MD-80 and MD-90, features five-section, double-position, full-range front edge slats; two section spoilers; three section flaps, double groove, trailing edge; and manually operated ailerons, connected by cable, operated differentially in flight for swing and swing control. The wings, with a wingspan of 93.4 feet, are swept 24 degrees for a maximum speed of Mach 0.82.

The T-tail, positioned high above the motors, eliminates engine thrust interference with its horizontal surfaces, whose elevators are connected by cable and operated manually, while the vertical stabilizer rudder is deflected hydraulically with an adjustment of cable flight The tail surfaces of the MD-95/717 employ thicker skins than those of the previous MD-80 or MD-90.

Powered by two BMW Rolls Royce BR715-A1-30 high-aft bypass turbofans, each with a thrust power of 18,500 pounds, the plane, completely free of the engine installation on its wings, generates the maximum wing lift for optimal performance. Based on the single core BR700, the BR715 features a two stage high pressure turbine; a 58-inch fan chamber; single crystal turbine fan blades; the largest combined blade and disc (blisk) ever used by a commercial power plant; and is equipped with thrust inverter. The 6,155-pound 19-foot-long engine, the third basic type that powered the DC-9 family, had run for the first time on April 28, 1997, almost reaching 26,000 pounds of thrust at this time. It is the only power plant of the MD-95.

The plane sits on a hydraulically driven double wheel tricycle undercarriage.

On October 19, 1995, ValuJet, an operator of DC-9 and MD-80, and the prototype, an ex-Oriental, had placed the launch order for the initially designated MD-95-30, consisting of 50 orders in Firm and 50 options. The DC-9-30 airlines modified to the MD-95 standard and registered N717XA, were launched three years later, on June 10, 1998, for the first time to the heavens on September 2. The plane, reflecting the previous Boeing The acquisition for one year of McDonnell-Douglas and its 7-dash-7 number scheme, had been redesigned "717", a nomenclature shared by Boeing's own KC-135A Stratotanker, the military derivative of 707.

The first production aircraft, registered N717XD, was first launched on January 23, 1999, and the type received its joint FAA and JAA certification nine months later, on September 1, after a 2,000 flight test program hours that included 1,900 individual departures and five cells.

The first aircraft, the N942AT, had been delivered to new-brand AirTran Airways, so far a 737 operator, which ValuJet had acquired intermittently, on September 23, and had been inaugurated in service the following month on the Atlanta- route Washington.

The 717-200, the initial and unique version, had been offered with basic and high gross weight options. The first, with 110,000 pounds, has a range of 1,430 nautical miles with a fuel capacity of 24,609 US gallons, while the last, with 121,000 pounds, has a range of 2,060 nautical miles with a fuel capacity of 29,500 US gallons, but it reduces the space under the floor due to the additional tank and requires the improved BR715-C1-30 engine of 21,0000 pounds of thrust.

The maximum certified altitude of the aircraft is 37,000 feet.

II

A triangular three-sector flight with AirTran Airways, from New York / La Guardia to Akron, Ohio; Atlanta Georgia; and back to New York, it is indicative of the mission for which 717 had been designed.
After a brigade of "mini-jets" of Canadair and Embraer, but reflected by the American MD-82 of "big brother" with long fuses and the identical AirTran 717-200 bound for Atlanta, immediately in front of him, 717 , which operates as Flight 202 and registered N926AT, crossed the arrivals runway, 4-22, before maneuvering towards the departure strip, Runway 13. Slightly loaded, with only about 20 passengers on board, the twin-engined T-tail aircraft He raised his main wheels. the concrete and was trimmed at a steep, initial ascent angle, putting its tricycle undercarriage in the air of 55 degrees, like a spring.

Overcoming the geometries of the Queens house and closing the gap with the opaque film of fine clouds like paper, Flight 202 leaned to the left of the Throgs Neck Bridge over the deep blue of Flushing Bay. Accelerating to rise in power, he leaned further to the left.

The island of Manhattan, which appears beyond the tip of the left wing in the form of a miniature and appears to float between Hudson and East Rivers, triumphantly projected its tall, thin buildings like spiers through the low, floating fog as victorious bulwarks of man & # 39; s architectural warfare. Beyond the Verrazano-Narrows bridge, the gateway to the Atlantic, the sun transformed the water into a reflection of copper crystal.

Now assuming a shallow and barely noticeable angle of ascent, 717, the latest evolution of DC-9, crossed the eastern fringes of the Allegheny Mountains, which looked like black waves and sketched in coal at 35,000 feet below.

Aided by the speed brake panels of the upper wing surface barely raised, the twin-engine aircraft began a shallow descent about 40 minutes later under layers of dirty white and gray clouds, indicative of January, towards the eastern farm patterns from Ohio, hitting through a light punch. .

The perpendicular runways of the Akron-Canton airport moved forward and to the left. Extending its leading edge slats, which produced significant resistance, Flight 202 completed its landing gear flutter sequence and the trailing edge, forming an arc on the final left bank of the approach course. Brushing the bare farm patches, lined with brown trees in the motor configuration that counteracts the resistance, the 717-200 exploded beyond the threshold of the track and slid sideways in an abrupt, crosswind contact.

After rolling through the circular brick terminal Akron-Canton, in which four United Express, US Airways Express and Delta Connection ERJ-135 and CRJ-200 had been discovered, the plane, the largest on the ramp, left its engines without stern mounted engines. of fuel, which fell silently, replaced by the sound of the jet bridge that extended to the front left passenger door.

Pushed back from the door in 1215, the AirTran 717, which now operates nonstop to Atlanta as flight 202, proposed its unobstructed taxi at the Akron-Canton regional airport and received immediate take-off authorization on runway 19. At disconnecting from the ground, the plane, with a considerable complement of passengers, withdrew its landing gear with a slight blow and climbed onto the patchwork quilt of Ohio farmland, which then gave way to gentle hills. With altitude, these were completely reduced to indistinguishable darkness.

Emerging from a white cloud that covered the green undulating topography of West Virginia and Kentucky at 37,000 feet, the twin-engine T-tail plane was parallel to the cotton nimbus line that had been tied along the east coast.

The chocolate brown ridges of the Great Smoky Mountains of North Carolina rose like solid waves that had petrified in their peaks and failed to descend back to the sea.

The speed brakes on the upper wing surface induced 717 in a rapid descent over Georgia to swollen and white snow banks, its bullet nose piercing the surrounding darkness like a penetrating missile. When performing banking operations on its longitudinal axis, it initiated a series of arrival aircraft that spaced S-turns, shaken by the disturbance of the air associated with the cloud, while the acceleration of the accelerator resulted in a series of periodic airspeak oscillations: As the airspeed took off, the engines were significantly wound, followed by a frequency of speed deterioration, before the process had been repeated.

The plane emerged from the cloud islands on the green and brown blanket of Georgia. The skyscrapers of Atlanta, although still in the form of miniature, appeared in sight from the left wing.

Extending your tricycle undercarriage in the gliding stream and raising your wings & # 39; The rope of the upper surface and the area at its maximum with the full path of the flap of the trailing edge, the 717 made a final left bank towards Track 28 in the pure blue skies of 68 degrees dotted with cotton lint suspended from sugar. Parallel to the left, with a Delta 757-200 and an ASA CRJ-100 approaching the 27-left and right runways, the pure T-tail jet crossed the threshold, lowering its engines for the last time, which profiled it for a flare, and crouched on the concrete with its main "rear legs" of the landing gear, which absorbed contact with a minimal protest.

The return flight, which operated nonstop, had occurred later than night.

An avalanche of points of light, which represents the final approach to the Atlanta Hartsfield-Jackson International Airport on that dark January afternoon, seemed to compete, at competitive speed, for the 27-left and right tracks, towards which the AirTran 717 -200, operating as flight 343 from gate C-12 to New York-La Guardia, currently taxed. Turning to the threshold to the right of the two parallel stripes, it accelerated in an acceleration roller that punctured the engine and, thanks to its horizontal stabilizers, generated a sufficient elevation to disengage from the Georgian soil and dive into the dive. , low cloud.

Withdrawing his landing gear, he stripped the darkness. The thin horizontal strata of fog made the orange lights of the ground become ethereal, a silenced attempt, only partially successful, to penetrate the veil from the "other side."

Separating from civilization, the twin plane was installed on its 35,000-foot autonomous plateau, from which it could see, but not touch, the world, in miniature, below. Curling on the east coast, it flew over Greenville / Spartanburg, South Carolina; Greensboro, North Carolina; and Richmond, Virginia, represented by their respective spots of ground light, "spills" of iridescent paint that had been thrown on the black canvas of the earth without form or foresight.

Directed, according to its flight plan, east of Washington and Philadelphia, flight 343, an autonomous and illuminated world that pursues its invisible path in the darkness of January, followed the coast of New Jersey.

Extensions of slats of the leading edge, which allowed the air velocity to bleed, occurred 40 miles from the airport. The Guard is approaching, to Track 22, it would take the plane north before it could become final.

Trapped momentarily in the black void and without references between the top of New York Bay and the night sky, the plane passed to the right of the small Statue of Liberty and the illuminated and bright sculptures of Manhattan Island, more beyond which the perpendicular airstrip … stamped field of La Guardia rolled up.

Following, precisely, the pattern of aircraft approach lights, the 717 leaned over the black reflective surface of Long Island Sound beyond the green light Throgs Neck and Whitestone bridges.

Executing a long and final approach over the Connecticut coast at a speed of 132 knots, the double jet untied its landing gear and extracted the last amount of elevation obtainable from its wings backwards with full drag edge fin extensions, a contradictory maneuver that created as much resistance as it rose and could only be really countered with greater engine power.

Leaning toward Flushing Bay with his nose, he passed over the pier that supported the threshold of Track 22 and exploded in the headwind, snatching the concrete again with its main wheels and unleashing its spoilers and thrust inverters in a simultaneous explosion. An American 737-800, which had preceded its landing, had just turned towards the parallel taxiway.

III

On May 23, 2006, during a ceremony attended by thousands, Boeing had deployed the last two 717 orders by Midwest and AirTran Airways, marking the final deliveries of the design, the last McDonnell-Douglas commercial aircraft and the closure of its historic Long Beach production facilities.

Founded by Donald W. Douglas, Douglas Aircraft Company had flown its first aircraft, the "Cloudster", in 1921, and had opened its Long Beach facilities in 1941, on the eve of World War II, when the demand had overshadowed the capacity in his country. existing plants in Santa Monica and El Segundo, California. Douglas's first commercial design, the DC-1, had been built here and sold to Transcontinental and Western Air (TWA), becoming the precursor to a long line of increasingly advanced piston aircraft that had introduced the world into flights commercial.

When merging with McDonnell Company in 1967, Douglas Aircraft Company was renamed McDonnell-Douglas, its products comprise the commercial division of the new corporation and, 30 years later, when Boeing acquired McDonnell-Douglas, it became the Douglas Products Division. Finally, it had been designated as the Long Beach Division of Boeing Commercial Airplanes.

During its more than 65 years of history, the Long Beach factory had produced some 10,000 military aircraft during World War II and 15,000 military and commercial design aircraft in general, while all its locations had produced more than 65,000 aircraft.

Despite the most efficient and cost-effective final assembly techniques designed by Boeing, the 717 could not remain competitive, partly due to sales conflicts with its own 737-600. However, the 156,717 produced, along with the previous generation 976 DC-9, 1,191 MD-80 and 114 MD-90, had already provided nearly half a century of robust, reliable and economical service worldwide, and seemed to be likely to do so in the coming years.