| 词条 | Lockheed L-649 Constellation | ||||||||||||||||||||
| 释义 |
The Lockheed L-649 Constellation was the first real civilian version of the Lockheed Constellation line, as the Lockheed L-049 Constellation was a simple redesign from the military Lockheed C-69 Constellation. The L-649 was planned to be the new standard version of the Constellation, but the L-749 Constellation, a co-jointly produced improved derivative, was chosen over the L-649 by most airlines. Most of the few L-649 aircraft built were delivered and operated by Eastern Air Lines. HistoryWhen Curtiss-Wright offered an improved version of the Wright R-3350 Duplex-Cyclone, Lockheed began developing an improved version of the L-049 Constellation airliner to be powered by this engine. The new project was designated L-049-84. In addition to the engine change, the wing and fuselage structure were strengthened to allow an increased gross weight. The cabin was redesigned and made more luxurious, incorporating changes such as retractable overhead sleeping berths, modernised air conditioning and retractable seats. Ten different cabin layouts were offered. Due to the loudness of the R-3350 engines, the insulation had been augmented through the use of multiple materials including non-inflammable cloth and fiberglass. The problem of overheating that plagued the original engines had been eliminated through the newer design of the R-3350 and the oil tanks being moved away from the engine nacelles. The oil tank capacity was also increased by 9 gallons. The payload was increased by 1,846 pounds. An extra removable cargo hold was designed to increase the payload of the aircraft. This was called a "Speedpak", and was to be used for shorter flights. The result was a completely new design, causing Lockheed to redesignate the aircraft L-649 due to the significant changes. The first L-649 flew on October 19, 1946, and it received its certification in May 1947. The first L-649 was also delivered to Eastern Air Lines in May 1947. Eastern had modified its original order for 14 L-049 Constellations to 14 L-649 Constellations. Eastern was also the only airline to receive the L-649 straight from the production line itself, as Trans World Airlines and Air France converted their ordered L-649 aircraft into the improved derivative, the L-749 Constellation, which was to be produced alongside the L-649. In fact, the L-749 entered service a month before the L-649 did. A further incident occurred when TWA suffered a pilots' strike, causing them to cancel the original order for 8 L-049 and 18 L-649 aircraft. Only 16 original L-649 aircraft were produced. Six others were converted to L-649A standard and delivered to Chicago and Southern Air Lines. Most of the L-649 and L-649A aircraft would later be converted to L-749 and L-749A standards. When Chicago and Southern merged with Delta in 1953, several of these airplanes were sold to TWA.{{sfn|Breffort|2006|pp=26-38}}[2][3] Variants{{Main|Lockheed Constellation variants}}
Standard production version, powered by four R-3350-749C18BD-1 engines. 16 built.
Strengthened structure and extra fuel capacity for longer distances. 6 built. Specifications (L-649){{aircraft specifications|plane or copter?=plane |jet or prop?= prop |ref= the American Museum of Aviation.[4] |crew= 5 (2 pilots, flight engineer, 2 stewards) |capacity= 60-81 Passengers |payload main= |payload alt= |payload more= |length main= 95 ft 3 in |length alt= 29.03 m |span main= 123 ft |span alt= 37.49 m |height main= 23 ft 8 in |height alt= 7.214 m |area main= 1,650 ft² |area alt= 153.29 m² |airfoil= |aspect ratio= 9.17 |empty weight main= 55,000 lb |empty weight alt= 24,950 kg |useful load main= 39,000 lb |useful load alt= 17,690 kg |max takeoff weight main= 94,000 lbs |max takeoff weight alt= 42,640 kg |engine (prop)= Wright R-3350-749C18BD |type of prop= radial engines |propellers=4 |power main= 2,500 hp |power alt= 1,865 kW |number of propellers per engine=3 blades |propeller diameter main= |propeller diameter alt= |max speed main= |max speed alt= |max speed more= |cruise speed main= 327 mph |cruise speed alt= 284 kt, 526 km/hr |cruise speed more= |stall speed main= |stall speed alt= |stall speed more= |never exceed speed main= |never exceed speed alt= |range main= 3,995 mi w/max fuel load; 2,290 mi w/max payload |range alt= 6,430 km w/max fuel load; 3,685 km w/max payload |range more= |ceiling main= 24,442 ft |ceiling alt= 7,450 m |ceiling more= |climb rate main= |climb rate alt= |climb rate more= |loading main= 57.0 lb/ft² |loading alt= 278.2 kg/m² |power/mass main= 9.4 lb/hp |power/mass alt= 5.72 kg/kW }} See also{{Portal|Aviation}}{{aircontent|related=
|similar aircraft=
|lists=
}} References
1. ^{{cite web|url=http://www.uswarplanes.net/c69c121.html |title=US Warplanes - C-69/C-121|accessdate= 6 September 2011|ref=harv}} 2. ^Lockheed Constellation Survivors - L649/L749 Constellation; Petersen, Ralph M.; Retrieved 6/5/11 3. ^California Classic Proliners - Lockheed Constellations; Gibson, Tom; Retrieved 6/5/11 4. ^The American Museum of Aviation - Lockheed L-649 Technical Specifications; Retrieved 9/6/11
External links{{Commons|Lockheed Constellation}}
7 : Lockheed aircraft|United States airliners 1940–1949|Four-engined tractor aircraft|Low-wing aircraft|Lockheed Constellation|Aircraft first flown in 1946|Four-engined piston aircraft |
||||||||||||||||||||
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。