Powerplants were the key to commercial aircraft capability range, and performance, and all were integrated from the 747-200B when the 63,000 thrust-pound Pratt and Whitney JT9D-7Q became available. First ordered by Northwest Orient, but quickly followed by Braniff, Japan Air Lines, Singapore Airlines, and Avianca, the model, introducing lighter nacelles, offered a two- to three-percent reduction in fuel consumption.
While an increased capacity variant was considered during the earliest days of the 747 program, these engines paved the way for serious reconsideration without the prior need to sacrifice range or cargo loads for it.
Towards the end, studies performed in 1976 concentrated on a 23-foot fuselage stretch, achieved by way of seven-frame forward and eight-frame aft insertions, together with a 27-foot upper deck increase, for a new combined class passenger capacity of 570, as opposed to the previous 440. Yet depressed passenger demand throughout the late-1970s precluded the viability of this ambitious project and airline customer consensus pointed to a stretch that was more modest.
This took shape as the 747SUD, or”stretched upper deck,” in the spring of 1980. It comprised two upward-opening doors and 18 windows with 45-foot-long evacuation slides. Even though it carried an 8,000-pound, or two-percent, structural weight growth, the differently simplified modification increased its six-abreast lodging from 32 to 69, reached by a brand new, straight, inner staircase that replaced the type’s signature spiral one.
Designated 747-300, it was provided as both a new-build version or a conversion of existing 747-200Bs, both of which factored into launch customer Swissair’s June 1980 arrangement for four of the former and one of the latter. Powered by four 64,750 thrust-pound JT9D-7R4G2 motors, it flew a couple of decades later, on October 5, also was kind certified a year after that on March 4 at an 833,000-pound gross weight.
It introduced neither increased range nor any sort of design enhancement, while the minimal change version offered a modest capacity increase.
747-400 Design and Development:
Several factors caused reconsideration of a derivative of the 747 in the mid-1980s.
Sales, foremost and first, had been declining. Seven airframes in 1979’s production rate had been reduced to a trickle of just one. Without revitalization, the program was likely to be terminated.
Currency and advancement, secondly, had not been maintained, a strategy that had kept the 727 and 737 programs alive with advanced versions, and the later, especially, had spawned the Next Generation 737-300, -400, and -500 series.
Competition, thirdly, although not necessarily on an even-keel basis, had started to appear with step-change technology, as occurred with the DC-10-30 and -40, whose succeeding MD-11 introduced quieter, more fuel efficient engines and two-person digital cockpits. Airbus itself was going to unveil its twin- and quad-engine A330 and A340 designs. The 747 appeared particularly outdated with its three-man, analogue cockpit, especially when measured against Boeing’s own new-technology narrow and widebody 757 and 767 offerings.
Growth had changed to the Pacific from the Atlantic, with unprecedented numbers of amounts and passengers of freight.
What was needed was a modernized version of the venerable 747 with significant range to get rid of the intermediate stops in Alaska and Hawaii, yet not sacrifice payload. The remedy was originally envisioned as a variation of the 747-300 with either Pratt and Whitney PW4000 or General Electric CF6-80C turbofans, an increased wingspan, and its resultantly increased wing integral fuel tank capacity.
Yet, most of the major, ancient 747 operators sought far more than these simple power and dimensional increases packaged in the projected 747-300A, prompting Boeing to embark upon a comprehensive reassessment project so the new version would be commensurate with late-20th century technology.
Devising, in fact, a five-point list to generate next-generation earnings, it sought to integrate state-of-the-art technology, considerably improve the passenger cabin, increase the range from 1,000 miles, reduce fuel consumption by up to 37-percent over that of the initial 747-100, and decrease operating costs by ten percent.
Designated declared in May of 1985 and 747-400, it was a considerably improved aircraft.
Although it retained the 231.10-foot overall length of all the prior standard versions and featured the stretched upper deck of the -300, it introduced a considerably modified wing. Built up of the 2000 aluminum and 7000 zinc set of aluminum alloys developed for the 757 and 767, which formed the torsion box’s upper and lower skins, and incorporating graphite composites, it featured both a six-foot span increase and six-foot winglets which were apparently canted by 29 degrees and had a 60-degree sweepback. Eliminating the need for a larger span improve, these area-rule designed apparatus exploited the vortex created by the upper and lower pressure differential remix at the tip, increasing lift and area, reducing drag, and keeping gate compatibility dimensions a greater stretch would not have achieved.
“Winglets,” according to Boeing,”are a new stabilization feature to compensate for body and wing structural changes.” They facilitated the transport of 40 more passengers 2,500 miles further.
While the ailerons, spoilers, and dual-section, triple slotted trailing edge flaps remained exactly the same as those integrated on previous 747 versions, yet another variable camber leading edge flap has been set up, resulting in three inboard Krueger apparatus from the origin to the inboard motors, five mid-wing ones between the powerplants, and the new total of six between the outboard one and the tip.
The building materials increased the wing’s power by between five and 13 percent, yet reduced aircraft weight by up to 5,500 lbs. When compared with the 195.8-foot span of the previous versions, the 747-400 had a 211.5 unfueled one or 213.0 one with full tanks, which caused a downward bend of the airfoil. Aspect ratio was 7.7 and region was 5,825 square feet.
Another improvement was its powerplant. Because engine manufacturers had made considerable progress in the design and development of advanced turbofans, particularly for long-range, widebody twins which were predicated upon enhanced reliability and thrust and decreased fuel consumption and noise, the latest 747 version was 40-percent quieter than its -300 series predecessor. It was provided with poweprlants as had occurred with the 747-200B.
Seven percent less fuel was swallowed by it than the earlier JT9D upon which it was based.
The 58,000 thrust-pound General Electric CF6-80C2B1F, first specified by KLM Royal Dutch Airlines, provided a four-stage low pressure compressor matched to the fan, a core airflow that increased from 276 to 340 pounds per minute, and an overall pressure ratio of 30.4 to 1 generated from the 14-stage high pressure compressor. Like the PW4056, it was FADEC-equipped.
The Rolls Royce RB.211-524, including three-shaft, wide-chord blades, was offered in two versions: the 58,000 thrust-pound -524G and the 60,000 thrust-pound 524H. It was first ordered by Cathay Pacific.
All engines, irrespective of type, were attached to redesigned, compact pylons.
While the aircraft was on the floor with a one it could maintain a Fahrenheit cabin temperature.
Fuel, whose capacity varied between 53,985 and 57,285 US gallons for Pratt and Whitney and Rolls Royce engine-powered aircraft, and between 53,711 and 57,011 US gallons for General Electric powered ones, was stored in the fuselage center section and two chief tanks per wing, together with reserve and vent surge tanks. Although minor modifications were made to their plumbing and sensors, the 747-400’s major design feature was a 3,300-US gallon auxiliary tank in the 72-foot, 2.5-inch spanned horizontal tailplane, providing a 350 nautical mile increase. It was not, however, used for in-flight center-of-gravity version.
Increased rudder authority, amending maximum deflection from a former 25- to a current 30-degrees, facilitated a ten-knot ground speed decrease in which it could maintain the effectiveness.
While the 747-400 retained the same five-truck, 18-wheel configuration of the earlier versions, it replaced the former steel brakes with carbon ones, which provided a 1,800-pound weight reduction, were rated for twice the number of landings, and cooled faster, increasing aircraft turn-around times. A wheel diameter increase was required by larger tires from 20 to 22 inches. Ai digital system was introduced.
Ice and rain protection encompassed total air temperature probes; window wipers, washers, and rain repellent; window heat; pitot-static probes on either side; angle-of-attack detectors, again on both sides; wing anti-ice; and motor inlet cowl anti-ice.
Aircraft servicing points were many. Those on the wing surrounded the gas vent, the gravity fuel port, the fuel itself, and the fuel control panel on the left wing underside.
Substantial improvements were made to the interior.
The cockpit, first and foremost, was transformed from a three- to a two-person one, with the fight engineer’s functions having been integrated in an overhead panel and these were automatically monitored.
Employing digital systems intended for the 757 and 767, it featured six eight-by-eight inch cathode ray tube (CRT) displays, comprising the principal fight display (PFD) and the navigation display (ND) placed side-by-side facing the captain and duplicated for the first officer, and 2 centre engine indication and crew alerting system (EICAS) screens.
An extensive data base, subdivided into navigation and performance groups, replaced the performance manuals and navigation charts, and facilitated the rapid, extremely accurate calculations of any desired parameter in combination with the flight management computer (FMC).
Information was both enterable and retrievable by means of the controller unit keypads.
Yet enough display space remained for additional aircraft status indications, including flap and undercarriage positions.
When compared with the 971 lights, gauges, and switches of the first generation 747’s analog cockpit, the present -400’s electronic one featured only a third, or 365.
Boeing listed its battle deck avionics baseline capacities as follows.
“8 x 8 incorporated displays: air data, primary flight and navigation instruments; engine, subsystems, caution and warning alarms; systems status and synoptic (heads-down observation ).
“Advanced FMC software bundle: thrust management – autothrottle/thrust limit; altitude/speed flight profile intervention through AFDS MCP; Nav radio tuning – remote and automatic; worldwide nav data base capability; software improvements.
“Central maintenance computer system (CMCS): standardized subsystem bite with English language readout; interactive control of system LRU bite through MCDU; interfaces flight deck//avionic and associated airplane systems.
“Improved dispatch reliability: redundant constraint of mode functions for EFIS/EICAS/AFDS MCP; display function shifting and triple EIFS/EICAS interface units.
Besides two observer seats, a windowless crew rest compartment, including a couple of full-length bunks, squirrel removal companies, reading lights, and fresh air vents, enabled extra pilots to attain legal break periods on struggles that may span up to 18 hours. A comparable, although much larger, cabin crew rest area, installed in the formerly unutilized back roof from the last row of passenger seats to the rear pressure bulkhead and replacing the 747-300’s”Portakabin” one that had taken the place of up to 20 revenue-generating passenger ones, was accessible by a door that was locked, three-step, and vertical ladder entryway. Incorporating ceiling lighting and additional insulation to simulate day and night cycles, it was configured with varying quantities of sleeper seats and bunks.
The redesigned interior, which introduced an innovative widebody look, featured recontoured ceilings and sidewalls; hidden lighting; self-supporting ceiling panels; larger overhead side and centre storage compartments; outboard, seat track lockable modular galleys; modular, vacuum flushable toilets, whose waste was stored in four back tanks; plus a digital in-flight entertainment system with seat-back monitors; and five main deck air conditioning zones with higher ventilation.
Access, as was provided on the 747-300, was via a stairway.
Class division, density, ability, color, fabric, and decoration varied according to client specification. A 416 tri-class configuration, for instance, entailed 23 first class seats in a 61-inch pitch, 80 business class ones at a 39-inch pitch, and 313 coach class ones in a 32-inch pitch. A cabin adapting 497 42 first class and 455 coach seats. Five hundred eleven could be subdivided into 42 business class seats in a 42-inch pitch and 406 coach ones in a pitch, with another 76 on the stretched upper deck, provisioned with its own galleys and lavatories.
Maximum main deck abreast seats in the four cabins behind the nose was ten, with two aisles, and six to the top deck with one aisle. Maximum passenger capacity was 624.
The 747-400’s lower deck hold volume of 6,035 cubic feet was subdivided into 5,190 cubic ft of unit loading device (ULD) distance and 845 of bulk or loose-load space, facilitating the loading of 16 forward and 14 aft LD-3 containers or five forward and four aft 96-by-125-inch pallets.
As powered by the CF6-80C2 engine, it had a 390,700-pound working weight, 144,300-pound payload capability, 535,000-pound zero-fuel weight, 384,824-pound fuel weight, a maximum takeoff weight that varied from 800,000 to 870,000 pounds, and a maximum landing weight that varied from 574,000 to 630,000 pounds. Range, in a cruise rate with reserves and 412 passengers, was miles.
Construction of the first 747-400, enrolled N401PW, began in. Northwest’s launch order, for ten, called for aircraft configured for 420 passengers. Major assembly occurred a little over a year in September, and the, on January 26, 1988, entailed a dual-ceremony, dual-location event, since it marked the occasion of the rollout at Renton. Another 58 aircraft, by Air and United France, had been ordered.
The anticipated system glitches, in addition to delivery delays and the unexpected part, postponed the PW4056-powered aircraft’s flight from March followed by Rolls Royce examples and General Electric in, respectively, August and June. The GE airframe set a world weight record, leaving the runway.
Certification, following a flight test program, was achieved on January 9, 1989. Delivered to Northwest 17 days later and entering domestic service between Phoenix and Minneapolis on February 9 for team familiarization purposes, the first 747-400, powered by PW4056 turbofans, was put in the Pacific-spanning skies it was intended for, from New York to Tokyo, on June 1.
Other first deliveries comprised those to Lufthansa and KLM, on, respectively, May 18 and May 23 to Cathay Pacific on June 8 with Rolls Royce powerplants, and with General Electric engines. From London, the kind set a world distance record on the August 17 delivery flight to Qantas to Sydney, covering the 9,688 miles in 20 hours, eight minutes.
By May 25, 1990, 279 firm orders had been attracted by the 747-400.
As had happened with the 747 that was fundamental, and especially with its -200 B series, Boeing offered variants of the 747-400.
The first of them was the 747-400 Combi Featuring combinations of primary deck passenger and cargo loads, the latter in two aft zones, it comprised a 120- by 130-inch aft, port, upward-opening door, reinforced flooring, and freight loading system, facilitating several load combinations, such as 268 passengers and seven pallets, 290 passengers and dix pallets, or up to 13 pallets. The type was delivered to KLM.
Another version was the 747-400D for”domestic.” Considered an innovative counterpart to the earlier 747SR for short, high-density Japanese businesses, it omitted the right-wing wing extensions and winglets, was powered by thrust motors, and offered a maximum takeoff weight, though it was certifiable up to 870,000 pounds.
The first 747-400D, which was all versions’ 844th 747 airframe, first flew in March of 1991 and was sent to Japan Air Lines in October. Another operator, all-Nippon Airlines, configured the aircraft for 542 economy class passengers and 27 business.
The 747-400F replaced the 747-200F, whose creation was stopped after a launch order was placed by Air France on September 13, 1989 for five. Devoid of passenger windows and facilities, and using the upper deck of -200 the 747-100, and – SP, it featured both upward-opening nose and side cargo doors, a flight ladder, and a crew rest area. It could carry 26 tons of freight 1,200 miles farther.
Volume totaled feet, such as 21,347 on the deck, 5,600 from the lower deck holds, and 520 in the majority. Two ten-foot high pallets might be accommodated on the deck.
The 968th 747 built, the, was rolled out on February 25, 1993, and first took to the heavens on May 4. The maximum gross weight of the type was 875,000 pounds. Cargolux inaugurated the kind into service instead Since Air France had since canceled its order.
The last version was the 747-400ER, intended, as its designation indicates, for”extended range” operations.
Powered by PW4062 motors, the -400ER had a 652,000-pound landing weight, a maximum takeoff weight, and a 535,000-pound zero-fuel weight. Design range with 416 passengers was 7,585 miles.
By January 1, 2002, 41 operators had arranged 630 747-400s of all versions. Production totaled 694.