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Aviation History
1956
1956 - 0912.PDF
58 tooo 2,000 3,000 4.000 FLIGHT DISTANCE (St. m) 5.OOO 6,000 3OOr 2SO- 2-6O- 2 4O- z UJU 2OO ISO 1 1 1 \ \\ \ \ \ 1 • ^_ A D - C B '•> 1,000 2,000 3,000 4,000 5,000 50O t5OO 2.5OO 3.5OO 4.5OO 5.5OO FLIGHT DISTANCE (stm) D and I are domestic (16,960 Ib pay load) and international (16J60 Ib) aircraft; A, B, C and D are long-range cruise heights falling from 22,600ft to WflOOft; 1955 A.T.A. method with 3 hr reserve fuel. Airliners of the World L. I 6 49 A ally released for use as a speed brake at indicated speeds up to 233 kt(269 m.p.h.), without power, the leg free-falling and locking over the dead-centre in the down position. The legs carry twin wheels withanti-skid, hydraulic disc brakes. A legacy from early Constellations is the fact that the nose gearretracts backwards—an unusual feature in modern aircraft and one which Lockheed would no doubt have liked to change. In order toensure positive lowering, the unit can be extended by either of two actuating cylinders, each served by its own hydraulic system; emergencyextension can be affected by an electrically driven, stand-by pump. Flying Controls. All control surfaces are hydraulically boosted bya new pattern of Eclipse-Pioneer hydraulic booster similar to the units used on the C-130 military transport. The units for all three axes havetwin cylinders operated by independent systems; and should either system fail, the remaining power is ample for full control, with finalmanual stand-by. From the flight deck control movements are trans- mitted through simple cable systems, and the boosters drive push-pullrods which run in anti-friction bearings and drive the surfaces directly. Feel is retained. Empennage booster units are hung beneath the tail-plane. Therudder booster has a short linkage to a lever under the torque tube of the centre rudder, forward of which are mounted push-pull tubes,supported on links pivoted behind the tailplane rear spar, through which the drive is taken to the outer rudders. The elevator torquetube is driven directly, and an unusual feature of this surface is the mass balance carried on a long lattice girder, pivoted on the front spar of thetailplane. The aileron boosters are mounted on the back of the wing box at the aircraft centre-line and drive through push-pull rods behindthe rear web in each half wing. There are four large flap sections, the two outer portions havingreduced chord (52 instead of 56in) and all having a recessed upper sur- face to mate with the trailing edge of the upper fixed shroud. Eachflap section is of the Fowler type, although the tracks are initially straight so that only one-third of the final angular deflection is obtainedduring the first 85 per cent of flap travel. At the ends of the tracks the flaps encounter cams which push down the flap-rollers to fulldeflection during the last 15 per cent of movement. The track, roller and actuator assembly is almost identical with that of the Electra. Dualhydraulic motors are mounted inboard, driving the surfaces through torque tubes and ball-bearing screw-jacks, two of which drive eachsection of flap. At two points the flaps penetrate the wing box and castings are used to seal the tankage where this occurs. POWERPLANT. The engines are of the new EA series of WrightTurbo-Compound rated at 3,400 h.p. for take-off. In the 1649's EA-2 engine the reduction gear ratio has been reduced from 0.4375 to 0.355and the airscrews have been increased from 15ft 2in to 16ft lOin dia- meter, the largest used on any transport. The slow rotational speedwill reduce exterior noise level and this is further improved by the clearance of 62.6in between the inboard airscrews and the fuselage(more than four times as great as on the 1049). Each airscrew has only three blades, as in all previous Constellations, and two makes are avail-able; T.W.A., for example, have specified Hamilton Standard with forged light-alloy blades, and Air France are remaining faithful toCurtiss with hollow steel blades. The nacelle structures are built up from multiple rings and incor-porate boxes for the retracted main landing gear which leave the main integral wing structure undisturbed. Engine and airscrew loads aretaken oack through conventional tubular mountings to the firewall, from which point the loads are dispersed within the stress-bearingnacelle by heavy channels which fade out into the nacelle structure. A large saddle oil tank is mounted in each nacelle, the inboard tanksbeing of a curious L-fcrm with a long axial portion and a branch running down behind the firewall; the inner face of each inner tank is mouldedto fit the retracted main wheels and large, full-flow filters are incorporated. The double-skin petal cowling consists of a bottom portion hingedat the rear and a central upper beam, also hinged* at the rear and to FLIGHT, 6 July 1956 which are attached the two large side panels which hinge outwards.Carburetter air is drawn in through a flush intake beneath the up?er beam and ducted between the outer and inner skins. Oil coolers aremounted in separate air trunks beneath the lower portion of cowling. SYSTEMS. Air-Conditioning. It is in this system, more than anyother, that the 1649 shows the greatest departure from previous Constel- lation practice. Most of the basic equipment is packaged into identicalport and starboard assemblies in each outer nacelle, comprising two heat exchangers, an air-cycle unit and mixing valve, supplemented bya combustion heater in each wing fillet. Intakes to the two cabin blowers and primary heat exchangers are in the wing leading edge, andthe secondary heat exchangers draw air from intakes on the wing ""pressure air to the cabin is ducted inboard behind the wing box,passing through a water separator on the way, and enters the fuselage near each heater. It is then divided into different types of conditionedair, the major proportion being taken up through risers around both sides of the centre fuselage to a three-section roof duct. Extractionis at foot level, and pressure relief and inwards relief valves are mounted on the rear pressure-bulkhead. Flight-deck air is suppliedby a separate system, with an auxiliary fan and heater. Fuel. Every possible drop of fuel has been accommodated by makingthe entire wing-box, from tip to tip, into an integral tank. Reading from starboard to port the bays are numbered 1, 2, 5, 7, 6, 3 and 4.Between 2 and 5 to starboard and between 6 and 3 to port are dry bays behind the inboard engines. Tank 7 is a capacious box beneaththe cabin floor, filled from the port wing root via a large riser branch which pierces the root ribs. Provision is made for pressure- and gravity-fuelling and for emer-gency fuel-jettison. All booster pumps are mounted at the rear inboard ends of the tanks, feeding through lines contained wholly within thetanks as far as the front of the wing-box in line with each engine. Hydraulics. In conformity with Lockheed's strong leanings towardsfail-safe design there are two completely independent hydraulic systems, each operating at 3,000 lb/sq in. A multi-plunger Vickers pump iscarried on each engine, the pumps being tied in pairs to feed the dual systems. Services supplied include the undercarriage, flaps, wheelbrakes, control boosters and nosewheel steering. Electrics. A D.C. system is employed, supplied by six 375-ampgenerators feeding a stabilized line voltage of 30. Advanced protection and feeder-fault systems are incorporated and all cables are nylon-covered and resistant to synthetic oils and low-temperature, fire-resist- ant hydraulic fluids. Ice-Protection. Originally Lockheed considered the use of hot-airde-icing for the main plane but concluded that, owing to the thin wing- section and the very great span, it would be preferable to adhere to thepneumatic-boot method used in previous Constellations. Each leading- edge structure can be unscrewed from the front of the wing box, andthe profile is recessed so that the uninflated boots do not mar the exterior shape of the aerofoil. Goodrich high-pressure boots are used, cementeddirect to the outer metal skin. A similar method of protection is employed on all leading edges of thetail. The airscrews are de-iced by alcohol slingers fed from tanks in the outer nacelles, and Nesa windscreens and electric blankets on theh.f. aerial mast complete the protection. FLIGHT EQUIPMENT. Curiously, although the flight deck is fullyequipped for an operating crew of four, there is a navigator's station farther aft, completely isolated from the rest of the crew by a bulkhead.To starboard in this rear compartment is a crew-rest area. The seating for the radio officer and engineer is shown in the main drawing. Inpractice the extreme duration of possible 1649 schedules may require operation with two complete crews on board.Search radar is available, and all 1649s have the same nose profile irrespective of whether or not such equipment is fitted. An autopilotis standard and is coupled hydraulically to the flying-control boosters. PAYLOAD ACCOMMODATION. Owing to its long-range natureit is probable that most 1649s will be equipped to carry not more than 62 passengers in four-abreast seats of a new pattern.Although the payload is space-limited at the moderate level of 17,000 lb this can be carried for a still-air distance of 5,300 st.m.;standard seating is from 58 to 64, although up to 93 tourist seats can be installed if necessary. All passenger seats are stressed to 9g andare mounted on rails. Total floor area of the passenger cabin is 744 sq ft. The aggregate capacity of the two underfloor freight holdsis 540 cu ft; access is provided through doors on the under-side of the fuselage 30in x 40in and via 16in x 19.25in hatches in the floor.COMMERCIAL HISTORY. Early history has already been des- cribed and the following are present operators of "un-stretched" Con-stellations: L.049, Capital 12 (in process of selling these), Cubana 2, El Al 4 and T.W.A. 32; L.649/749, Aerovias Guest 2, Air France 20,Air-India International 3, B.O.A.C. 16, Eastern 19 (of which many have considerably exceeded 30,000 hr), K.L.M. 10, L.A.V. 2, SouthAfrican 4, and T.W.A. 39. Operators, or future operators, of 1049 Super Constellations are:L.1049, Eastern 14 and T.W.A. 10; L.1049C, Air France 9, Air-India International 2, Avianca 3, Cubana 1, Eastern 16, Iberia 3, K.L.M. 12,Pakistan International 3, Qantas 10, T.C.A. 7; L.1049D, Seaboard and Western 4; L.1049E, Air-India 3, L.A.V. 2 and T.W.A. 10;L.1049G, Air France 14, Air-India 3, Cubana 2, Eastern 10, Iberia 2, K.L.M. 4, L.A.V. 1, Lufthansa 8, Northwest 6, Qantas 2, Thai Airways2, T.A.P. 3, T.C.A. 2, T.W.A. 28, and Varig 3; L.1049H, California Eastern 3, Flying Tiger Line 10, Qantas 2, Seaboard and Western 5,Slick 5 and U.S. Overseas 2. The first L.1649A is due to fly in October and certificated machinesare to follow next spring. The first machines are now taking shape, and the wing and fuselage of the first were mated last month. Ordersalready placed are: Air France 10, Lufthansa 4, L.A.I. 4, T.W.A. 25 and Varig 2. All these orders are to be fulfilled from 1957, except forLufthansa who get their first 1649 in 1958. The price of each with snares, is about £1.25m.
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