Beechcraft 50 Twin Bonanza / L-23 / U-8
The Twin Bonanza first flew in November 1949 (TC 5A4). Widening the Model 35 Bonanza fuselage to accommodate three abreast and placing an engine on each wing equalled the Twin Bonanza.
The US military used the Twin Bonanza as the L-23 Seminole,redesignated as U-8 in 1962. Four YL-23 were purchased in 1952 [52-1800/1803]. These were followed by 55 L-23A models [52-6162/6216] (most rebuilt later as L-23D.
Beech YL-23 62-1801
Forty L-23B [53-6153/6192] were purchased and a single XL-23C [55-3465] in 1955, converted to U-8G.
Both civil and military versions continued to be developed through various marks. By 1955, 96 L-23As and Bs were built.
Both civil and military versions continued to be developed through various marks. In 1958 the US Army sought an up-grade which lead to the development of the L-23F with its enlarged cabin.
It was the first post-war light twin to reach quantity production in the United States, and late models grossed 7300 pounds. Built with 260, 275, 295, and 340-hp Lycoming engines, the Twin Bonanza design has proved highly versatile. Beech produced the military U8 Seminole, the civil Queen Air and early King Airs from the Twin Bonanza wing, and Swearingen has marketed a conver-sion of the basic Twin Bonanza as the Excaliber. The design started life as a six-seater, and a seventh was added on the J model in 1960. There is so much room inside that numerous luxury executive interiors have been custom-installed. The aircraft has also been successful as an ambulance plane with room for a stretcher and medical attendants, in addition to the crew.
Excalibur / Beech Twin Bonanza
Engines: 2 x Lycoming IO-720-A1B, 400 hp.
Wing loading: 22.7 lb/sq.ft.
Pwr loading: 9.5 lb/hp. Max TO wt: 7600 lb.
Empty wt: 4768 lb.
Equipped useful load: 2500 lb.
Payload max fuel: 1120 lb.
Range max fuel/ 75% cruise: 901 nm/4.4 hr.
Range max fuel / 55% cruise: 1156 nm/ 6.3 hr.
Service ceiling: 22,200 ft.
75% cruise: 204 kt.
55% cruise: 185 kt.
Vmc: 78 kt.
Stall: 71-80 kt.
1.3 Vso: 92 kt.
ROC: 1870 fpm.
SE ROC: 440 fpm @ 102 kt.
SE ceiling: 11,800 ft.
Min field length: 2178 ft.
Fuel cap: 1380 lb.
Engines: 2 x 260hp O-435
Engines: 2 x 260 h.p. Lycoming GO-435-17
Span: 45 ft. 3 in.
Weight: 5.500 lb.
Max. Speed: 202 m.p.h.
Range: 985 miles at 190 m.p.h.
L-23D / E/F-50 / U-8D / RU-8D / RU 8D Seminole
Engines: 2 x 340hp O-480
Useful load: 2026 lb
Max speed: 233 mph
Cruise speed: 203 mph
Range: 1355 mi
No built: 85 [56-3695/3718, 57-6029/6094, 57-3084/3101, 58-1329/1353, -1357/1364, -3048/3092, 59-2535/2543, -4990/4992], included remanufactured L-23As.
Radar photo-observation, from civil E50
No built: 9
L-23E / U-8E / D-50
Engines: 2 x 295hp GO-480
No built: 6 [56-4039/4044], plus 1 civil to military to civil [N1779G=66-15360=N5375G=N888JE=N74GV].
Conversion of L-23D/23E
No built: 23 [55-3465, 56-3710, -4039, -4041, -4043, -4044, 57-6085 -6089, 58-1329, -1336, -1348, -1357, -1359/1360, -1363, -1364, -3055, -3057, -3062, 59-2536/2538, -4990].