Beech entered the field of pressurised general aviation aircraft following a first flight of the Beech Model 60 Duke on 29 December 1966. The Duke was intended as a luxury four/six-seat aircraft, and overall configuration was similar to other Beech twins. It was intended for operation at higher gross weights and had strengthened landing gear, and much more powerful Avco Lycoming TIO-541-E1C4 380-hp turbocharged engines.

The Duke uses turbo bleed air to obtain 4.6 psi cabin pressure, which will maintain a 10,000-foot cabin altitude all the way to 24,800 feet. Two separate baggage compartments in the nose and aft fuselage handle 500 and 315 pounds of luggage, respectively. The spacious Duke cabin provides a center aisle separating the seats, plus dividers between the flight deck and passenger cabin. A 20 per cent increase in range and new landing lights on the retractable gear were the changes for 1976. As an option, the pressurized twin can hold up to 232 gallons of usable fuel by adding wet wing tips. This boosts the fuel load by 90 gallons over the 142 gallons standard fuel load. The previous option allowed a maximum of 202. In 1977, the Duke advertised a higher cruise speed, improved exterior lighting and a standard Collins avionics package. In 1980, a Hoskins fuel-flow system indicates flow in gallons and pounds per hour, plus fuel remaining. Timing modes calculate flying time remaining and elapsed time since engine start.

Only two revised versions of the original Model 60 appeared during the production run, the Model A60 and Model B60 introduced in 1971 and 1974 respectively. The first provided a 23kg increase, in maximum take-off weight, the second a slightly larger cabin and increased fuel capacity. Such an aircraft was by no means cheap and, by American standards, was built in comparatively small numbers, with a total of 596 completed by the end of production in 1983.

BE-A60 Duke
Engines: 2 x Lycoming TIO 541 EIA4 6 cylinder turbocharged, 380 hp each.
Length: 33 ft 10 in.
Wingspan: 39 ft 3 in.
Speed: 286 mph.
Ceiling: 31,000 ft.
Range: 973 mls.

BE-B60 Duke
First built: 1968.
Engines: Lycoming TIO-541-E1C4, 380 hp each.
TBO: 1600 hrs.
Props: Hartzell 3-blade, 74-in, constant speed, full feathering.
Seats: 4/6.
Wingspan: 11.97 m / 39 ft 3 in
Length: 10.31 m / 33 ft 10 in
Height: 3.76 m / 12 ft 4 in
Wing area: 19.78 sq.m / 212.91 sq ft
Wing aspect ratio: 7.2.
Cabin length: 11 ft 10 in / 3.61 m
Cabin width: 4 ft 2 in / 1.27 m
Cabin height: 4 ft 4 in / 1.32 m
Maximum ramp weight: 6819 lbs.
Maximum takeoff weight: 6775 lb / 3073 kg
Empty weight equipped: 4235 lb / 1921 kg
Standard empty weight: 4425 lbs.
Maximum useful load: 2394 lbs.
Maximum landing weight: 6775 lbs.
Wing loading: 31.8 lbs/sq.ft.
Power loading: 8.9 lbs/hp.
Maximum usable fuel: 232 USG/1392 lbs.
Best rate of climb: 1,601 fpm @ 120 kts.
Climb gradient: 801 ft/nm.
Rate of climb @ 8,000 ft: 1460 fpm.
Certificated ceiling: 30,000 ft.
Service ceiling: 30,800 ft / 9390 m
8000ft cabin alt @: 21,600.
Maximum single-engine rate of climb: 307 fpm @ 110 kts.
Single-engine climb gradient, sea level: 165 ft/nm.
Single-engine service ceiling: 15100 ft.
Maximum speed: 246 kts.
Max cruise 79% pwr 25,000ft/7620m: 241 kt / 278 mph / 447 kph
Cruise @ 65% pwr @ 8,000ft: 185 kts.
Cruise @ 65% power @ 18,000ft: 201 kts.
Fuel flow @ 65% pwr @ 18,000 ft: 223 pph.
Endurance at 65 % pwr @ 18,000 ft: 6 hrs:
Range 45% 15,000ft/4750m opt fuel 45min res: 1023 nm / 1177 mi / 1893 km
Range 75% 25,000ft/7620m opt fuel 45min res: 837 nm / 963 mi / 1550 km
Stalling speed clean: 81 kts.
Stalling speed gear/flaps down: 73 kts.
Turbulent-air penetration speed: 160 kts.
Nose baggage capacity: 50 lb / 226 kg / 32 cu.ft / 0.91 cu.m
Cabin rear capacity: 315 lb / 143 kg / 28.25 cu.ft / 0.80 cu.m

First flown in June 1969, the Baron 58 became a part of the lineup in 1970, replacing the 56TC, and used the 285-hp Continental engine. It had the fuselage lengthened by 0.25m to provide a more spacious cabin, and an extension of the wheelbase. Ready acceptance of this improved Baron, with delivery figures that averaged about two per week for more than 12 years, resulted in the introduction of a pressurised Model 58P, with first deliveries in late 1975. Beechcraft has added two new versions, the 58P for over-the-weather pressurized comfort and the Baron 58TC for high-altitude performance.
The Baron 58P, Continental TSIO 520 L, 310 hp each, was priced at $200,750 (1976), with propeller synchrophasers as standard. Both these additions use the same 310-hp turbocharged Continental engines enabling them to have a service ceiling of 25,000 feet and above. The Model 58P combined the Model 95-B55 wings, Model 58 tail unit, a strengthened Model 58 fuselage to cater for pressurisation, and main landing gear units as developed for the Model 60 Duke.

All Baron 58s have accommodations for four to six passengers with optional club seating where the rear two pairs face other.
By mating the turbocharged powerplants and beefier wings of the pressurized Baron with the lighter fuse-lage of the Model 58, Beech has developed a versatile light twin that capitalizes on the performance advan¬tages of turbocharging without adding the cost and weight of pressurization. Everything about the 58TC that doesn’t involve pressurization is identical to the equivalent part of the Baron 58P: its wings and landing gear accept the same increased gross weight of 6,100 pounds, its en¬gines also are 310 hp Continental, and its fuel tanks hold an optional capacity of 190 usable gallons. But the 58TC doesn’t require the extensive pressurization hardware, wider window posts and smaller rear door that characterize the 58P. The standard Baron 58 fuselage with its convenient double rear entry doors has been retained to produce an aircraft with the alti¬tude performance of the 58P but with a considerably lower empty weight, a 35 percent higher floor loading capacity and a lower price tag.
Automatic wastegate turbocharging, which is the type used on the Baron 58TC, allows an engine to deliver its rated horse¬power up to the altitude where the wastegate is fully closed and no more exhaust can be diverted to the turbocharger. For the 58TC, that “critical altitude” is higher than its certif¬icated ceiling of 25,000 feet, which was es¬tablished on the basis of the 58P design re¬quirements, since FAR 23 places additional structural requirements on pressurized air¬craft operating above FL 250. (The 58TC and the 58P share the same type certificate.)
By conditionally restricting the maximum rpm to 2,600, Beech was able to certificate the 58TC to the noise standards that were scheduled to become law in 1980, but that also reduced the normal operating power of each engine from the P Baron’s 310 at 2,700 rpm to 301 hp. The pressurized Bar¬on therefore enjoys slightly better twin en¬gine takeoff performance compared with the 58TC because it has three percent more power available continuously from its en¬gines, but single engine performance and op-erations below 97 percent power are the same for both aircraft whenever they are flown at identical weights.
Unlike earlier Barons, the 58P and 58TC are certificated under FAR Part 23, amend¬ments 1 through 12. The 58P went through an en¬tire certification process (as opposed to a testing of only the things that have been changed). The wings of the P and the TC have been strengthened with heavier spars, thicker leading edge skin and an extra attach point on a stub spar as on the Duke, which is built in the same plant. And while they were at it, Beech’s designers also put Duke landing gear and brakes on the new Barons.
Beechcraft 58P pressurized Baron looks like a Baron 58 but the windows are slightly smaller. A quarter inch comes off all the way around in the process of adding beef to the structure for pressurization. There’s a door at the left rear as well as the standard right front door. Some side mounted airscoops adorn the engine nacelles, and the nacelles are slightly longer than on the other Barons.
Comparing the Pressurized Baron with the regular 58, there are two basic differences: the 58’s engines are not turbocharged, and its cabin is not pressurized. The airplanes have about the same speed down low; the 58P starts to move away up high, where the turbochargers do their thing. However, because climbing time must be considered, the time en route on most trips would be very close, unless the 58P were to find a more favorable wind up high. The cabins are the same, and the useful loads are close. In operational range, the 58 has a rather clear advantage over the 58P. It also has almost twice the single engine rate of climb at sea level, but the 58P’s turbo-chargers turn the tables on that score at altitude.
An increase in structural capacity allows the 58TC to carry 350 pounds more than the Baron 58. In 1977, a new three-blade propeller is standard on the 58P. Two inches shorter, it improves maximum speed and in-creases the climb rate by more than 100 fpm. That year, club seating in all models, simplified fuel management, and increased optional fuel capacities were added.

Beech made significant changes in the 58P for 1979. Horsepower increased from 310 to 325 per side, with the Continental TSIO 520 WB replacing the 520 Ls used previously. A heavier crankcase and improved pistons and crankshaft were the main internal changes, allowing the maxi¬mum manifold pressure to be raised from 38 to 39.5 inches. The extra power permitted not only a 100 pound increase in maximum gross weight, but also a higher single engine rate of climb. The cabin pressure differential also went up from 3.7 pounds per square inch to 3.9 psi, giving a cabin altitude of 11,800 feet when the airplane is at its 25,000 foot maximum certificated ceiling. Optional 196 USG fuel tanks (190 usable), comprising four interconnected quick ¬drain cells in each wing.
4700 Barons had been delivered by 1980, by January 1989 2,182 Model 58s had been delivered. Optional equipment on the 58, E55 and B55 are heavy-duty brakes that offer up to 50 per cent greater stopping power. In 1979, the pressurized Baron’s performance was enhanced by an increase in horsepower from 310 to 325 with the Continental TSlO-520-WB six-cylinder engine. Providing a higher degree of performance, the turbocharged, fuel-injected engine is exclusively a Beech powerplant — shared only by the 58TC. With the additional horsepower, the Baron 58P has a top speed approaching 300 mph. The P Baron’s pressurization system fea¬tures a variable rate controller, which allows cabin climb to be adjusted in relation to air¬craft climb: you can smoothly reach maxi¬mum pressure differential (3.7 psi) at the same time you reach cruise attitude. The same is true on letdown.
Maximum cruise speed for the 58TC was increased to 277 mph. Pressurization differential in the 58P was increased from 3.7 psi to 3.9 psi, providing a sea-level cabin up to 8350 feet. At 25,000 feet, the Baron’s service ceiling, the cabin is a comfortable 11,900 feet.
The Baron’s range is increased by as much as 253 miles with optional wet wing tips added to the existing fuel cell system. The Baron 58’s capacity will be increased by 28 gallons and the 58P and 58TC by 24 gallons with the addition of the wet wing tips.
In addition to Beech production Barons, at least two turboprop conversions have been developed by other constructors. These include the SFERMA Marquis, produced in small numbers in France, and combining Beech-built Baron airframes with 328kW Turbomeca Astazou engines; and the American Jet Industries Turbo Star Baron powered by two 298kW Allison 250-B17 turboprops.

Baron 58
Engines: 2 x Continental IO-520-C, 285 hp
Wing span: 37 ft 10 in / 11.53 m
Length: 29 ft 10 in / 9.09 m
Cabin length: 12 ft 10 in / 3.01 m
Cabin max width: 3 ft 6 in / 1.07 m
Cabin max height: 4 ft 2 in / 1.27 m
Cabin volume: 135.9 cu.ft / 3.85 cu.m
Baggage compartment fwd: 18 cu.ft / 0.51 cu.m / 300 lb / 136 kg
Baggage compartment rear: 37 cu.ft / 1.05 cu.m / 400 lb / 181 kg
Extended rear baggage compartment: 10 cu.ft / 0.28 cu.m / 120 lb / 54 kg
Empty weight equipped: 3268 lb / 1482 kg
MTOW: 5400 lb / 2449 kg
Max cruise 75% pwr 7000ft / 2135m: 200 kt / 230 mph / 370 kph
Max ROC SL: 1694 fpm / 516 m/min
Service ceiling: 17,800 ft / 5425 m
Range 65% pwr 11,00ft / 3355m: 1052 nm / 1212 mi / 1950 km +res
Seats: 4-6

BE-58 BARON 58
First year built: 1970.
Engines, Two Continental IO-520-CB @ 285hp each.
TBO: 1700 hrs.
Props: Hartzell 2 blade 78 in.
Seats: 4/6.
Max speed, 208kts.
Cruise speed, 6,000ft: 200kts,
Cruise speed, 8,000ft @ 65% pwr: 190 kts,
Cruise speed, 10,000ft: 195kts,
Cruise speed, 12,000ft: 184kts.
Fuel flow @ 65% pwr @ 8000 ft: 161 pph.
Endurance @ 65% pwr @ 8000 ft: 7 hr.
Cruise range: 1108-1339nm.
Climb rate: 2eng – 1660fpm @ 104 kts,
Climb rate: 2 Eng. @ 8000ft: 960 fpm.
Climb rate: 1eng – 390fpm @ 100 kts.
Climb gradient: 958 ft/nm.
SE climb gradient: 234 ft/nm.
Service ceiling 2 eng – 18,600 ft
Service ceiling 1 eng – 7,000ft.
Stall speed: 84 kts
Stall speed gear/flaps down: 74kts.
Take-off dist: 1336ft – to 50’: 2101ft.
Landing dist: 1439ft, From 50ft: 2498ft.
Empty wt: 3361lbs.
Max ramp wt: 5424lbs.
Max T/O wt: 5400lbs.
Max ldg wt: 5400lbs.
Useful load: 2063lbs.
Wing area: 199.2 sq ft.
Wing span: 37ft 10in.
Wing aspect ratio: 7.2.
Wing loading: 27.1 lbs/sq.ft.
Power loading: 9.5 lbs/hp.
Length: 29ft 10in.
Height: 9ft 6in.
Useable fuel: 136, 166 or 194 gal.
Turbulent air penetration speed: 156 kts.

BE-58P BARON 58P
First year built: 1975.
Engines: 2 x Continental TSlO-520-WB, 325 hp.
TBO: 1600 hrs.
Props: Hartzell 3 blade 78 in.
Seats: 4/6.
Max speed: 261 kts.
Cruising Speed: 65% pwr @ 8000 ft: 191 kts.
Cruising Speed: 65% pwr @ 18,000ft: 211 kts.
Cruising Speed: 75% power @ 20,000 ft: 247 mph,
Cruising Speed: 65% power @ 20,000 ft: 232 mph.
Fuel flow @ 65% pwr @ 18,000 ft: 189 pph.
Endurance @ 65% pwr @ 18,000 ft: 5.8 hrs.
Stall Speed: 84 kts, gear/flaps down: 78 kts.
Vmc: 81 kt.
Rate of Climb: Two engines 1475 fpm @ 115 kts
ROC @ 8000 ft: 1281 fpm, One engine 205 fpm @ 115 kts/SL, 107 fpm @ 115 kts/10,000ft.
Climb gradient: 770 ft/nm.
SE climb gradient: 141 ft/nm.
SE ceiling: 13,490 ft.
Takeoff (50 ft obstacle): 2761 ft.
Takeoff: 1654 ft.
Range: 75% power @ 20,000 ft: 937 mi, 65% power @ 20,000 ft: 1021 mi.
Certificated ceiling: 25,000 ft.
8,000 ft cabin alt @: 19,250 ft.
Turbulent air penetration speed: 170 kts.
Empty Weight 4010 lbs.
Max T/O Weight 6200 lbs
Max useful load: 2230 lbs.
Max landing wt: 6200 lbs.
Wing Loading 32.4 lbs/sq.ft.
Power Loading 9.5 lbs/hp.
Fuel Capacity 166 gals, 1140 lbs.
Wingspan 37 ft 10in.
Length 29 ft 11 in.
Height 9 ft 2 in
Wing Area 188.1 sqft.
Wing aspect ratio: 7.6.

Baron 58P
Engines: 2 x Continental TSIO 520 L, 310 hp.
TBO: 1,400 hrs.
Props: constant speed, full feathering, three blade, 80 in dia.
Length: 29 ft. 11 in.
Height: 9 ft. 2 in.
Wingspan: 37 ft. 10 in.
Wing area: 188.1 sq. ft.
Wing loading: 32.4 lb/sq.ft.
Seats: 6.
Empty wt: 4,374 lbs.
Useful load: 1766 lbs.
Max ramp wt: 6,140 lbs.
Gross wt: 6,100 lbs.
Pwr loading: 9.8 lb/hp.
Fuel cap: 166 USG/996 lbs.
Minimum runway requirement: 2,761 ft.
ROC: 1,424 fpm.
SE ROC: 205 fpm.
Max op alt: 25,000 ft.
SE service ceiling: 13,220 ft.
Max speed: 231 kt.
Cruise (75% power @ 20,000ft): 215 kt.
Cruise (67% power @ 20,000ft): 202 kt.
Range (75% power @ 20,000 ft, 45 min res): 814 nm.
Range (67 % power 20,000 ft, 45 min res): 887 nm.
Duration @ 67 % power, no res: 5.5 hrs.
Stall speed (clean): 80 kt.
Stall speed (gear, flaps down): 76 kt.

BE-58TC Baron TC
First built: 1976.
Engines: Continental TSIO-520-WB, 325 hp each.
TBO: 1600 hrs.
Props: Hartzell 3-blade, 78-in.
Seats: 4/6.
Length: 29.9 ft.
Height: 9.2 ft.
Wingspan: 37.8 ft.
Wing area: 188 sq.ft.
Wing aspect ratio: 7.6.
Maximum ramp weight: 6240 lbs.
Maximum takeoff weight: 6200 lbs.
Standard empty weight: 3793 lbs.
Maximum useful load: 2447 lbs.
Zero-fuel weight: 5700 lbs.
Maximum landing weight: 6200 lbs.
Wing loading: 33 lbs/sq.ft.
Power loading: 9.5 lbs/hp.
Equipped useful load: 2191 lb.
Payload max fuel: 1051 lb.
Range max fuel/cruise: 1077nm/4.4hr.
Range max fuel /range: 1403nm/7.0hr.
Maximum usable fuel: 1140 lbs.
Best rate of climb: 1,475 fpm @ 115 kts.
Climb gradient: 770 ft/nm.
Rate of climb @ 8,000 ft: 1329 fpm.
Certificated ceiling: 25000 ft.
Maximum single-engine rate of climb: 270 fpm @ 115 kts.
Single-engine climb gradient: 141 ft/nm.
Single-engine service ceiling: 13490 ft.
Maximum speed: 261 kts.
75% cruise: 241 kt.
55% cruise: 202 kt.
Vmc: 65 kt.
Vso: 77 kt.
Cruise @ 65% pwr @ 8,000ft: 191 kts.
Cruise @ 65% power @ 18,000ft: 211 kts.
Fuel flow @ 65% pwr @ 18,000 ft: 189 pph.
Endurance at 65% pwr @ 18,000 ft: 5.8 hrs:
Stalling speed clean: 84 kts.
Stalling speed gear/flaps down: 78 kts.
Turbulent-air penetration speed: 170 kts.

BE-58TC
Engines Continental TSIO 520 L, 301 hp @ 2,600 rpm.
TBO: 1,400 hrs.
Propellers Hartzell three blade, 78 in. diameter.
Length: 29 ft. 11 in.
Height: 9 ft. 2 in.
Wingspan: 37 ft. 10 in.
Airfoil NACA 23016.5 root, 23010.5 tip.
Aspect ratio 7.16.
Wing area 188.1 sq. ft.
Wing loading 32.42 lbs./sq. ft.
Power loading 10.13 lbs./hp.
Seats: 6.
Gross weight: 6,100 lbs.
Empty weight: 4,016 lbs.
Useful load: 2,039 lbs.
Payload with full fuel 899 lbs.
Fuel capacity (standard) 116 USG/996 lbs.
Fuel capacity (optional) 190 USG/1,140 lbs.
Baggage area 28 cu. ft.
Baggage capacity 470 lbs.
Minimum runway requirement 2,495 ft.
Rate of climb 1,461 fpm.
Single engine rate of climb 204 fpm.
Service ceiling 25,000 ft.
Single engine service ceiling 14,400 ft.
Maximum level speed 249 knots.
Cruise (74% @ 25,000 ft.) 231 knots.
Economy cruise (55 % @ 25,000ft) 202 knots.
Range @ maximum cruise (optional tanks, 45 min res) 1,020 nm.
Range @ economy cruise (optional tanks, 45 min res) 1,265 nm.
Duration @ max cruise (no res) 5 hrs.
Duration @ economy cruise (no res) 8.25 hrs.
Maneuvering speed 170 knots.
Stall speed (clean) 83 knots.
Stall speed (gear, flaps down) 75 knots.

2008 Beechcraft Baron G58
Engine: Continental IO-550C, 300 hp@SL
TBO: 1700 hr
Fuel type:100LL
Propeller type: CS
Landing gear type: Tri./Retr.
Max ramp weight:5524 lb
Gross weight: 5500 lb
Landing weight: 5400 lb
Maz zero-fuel weight: 5215 lb
Empty weight, std: 4050 lb
Useful load, std: 1450 lb
Payload, full std. fuel: 286 lb
Usable fuel, std: 194 USgal
Wingspan: 37 ft. 10 in.
Overall length: 29 ft. 10 in.
Height: 9 ft. 9 in.
Wing area: 199 sq. ft
Wing loading: 27.6 lbs./sq. ft
Power loading: 9.2 lbs./hp
Wheel size: 6.00 x 6 in
Seating capacity: 6
Cabin doors: 2 (3)
Cabin width: 42 in
Cabin height: 50 in
Cruise speed 75% power: 202 kt
Cruise speed 65% power: 192 kt
Cruise speed 55% power: 177 kt
Max range 75% power: 1052 nm
Max range 65% power: 1101 nm
Max range 55% power: 1388 nm
Vso : 75kt
Best rate of climb, SL: 1700 fpm
Best rate of climb, SE: 390 fpm
Service ceiling: 20,688 ft
Service ceiling, SE: 7284 ft
Takeoff ground roll: 2300 ft
Landing ground roll: 1300 ft

In 1967 the turbocharged 56TC entered production until replaced by the 58 baron in 1970.

56TC
Engines two 380-hp turbocharged Lycomings.
Seats 4-6.
Gross Wt. 5990 lbs.
Empty Wt. 3700 lbs.
Fuel capacity 142-204 USG.
Top speed 290 mph.
Cruise 284 mph.
Stall mph 84.
Initial climb rate 2020 fpm.
Ceiling 32,200 ft.
Range 1070 sm.
Takeoff distance (50’) 1420 ft.
Landing distance (50’) 2080 ft.

Developed from the earlier Model 95 Travel Air, the Beech Model 95-55 Baron was first flown on 29 February 1960. It differed mainly by having more powerful 260-hp Continental IO 470 series engines, plus design refinements that included swept vertical tail surfaces, and improved all-weather capability. The B55 Barons are powered by 260 hp Continental engines, which have 1,500 hour TBOs, provided their exhaust valves are either nickel coated or nimonic; otherwise a 1,200 hour TBO applies.

Beechcraft 55 Baron / T-42 Cochise Article

Deliveries of the 95-55 began in November 1960 with a list price of US$58,000, and this twin-engined four/five-seat aircraft resulted in further improvement and development of the type. The original 55 Baron became the A55 model. The Model B55, introduced in 1963, had four-seat and optional five/six-seat accommodation, and in 1965 an additional Model C55 was made available with more powerful 213kW / 285-hp Continental IO-520-C engines. The Model C55 incorporated a number of improvements, including increased tailplane span and an extended nose baggage compartment, and was developed later as a separate Baron model distinct from the B55.

A few months before the introduction of the C55, the US Army announced that the Model 95-B55 had been chosen for military service as an instrument trainer, which was ordered in an initial quantity of 55 under the designation T-42A Cochise (65-12679/12733).

Ten more were procured for US Army service (66-4300/4309) plus, in 1971, five for delivery to the Turkish army (71-21053/21057) under the Military Assistance Program. By 1984, production of civil and military 95-B55 Barons was in excess of 2,400 and 1,201 examples of the Model E55 (formerly C/D55) had been delivered when production ended.

In September 1967 deliveries began of a new Model 56TC Baron. This introduced two 283kW / 380-hp Avco Lycoming TIO-541-E1B4W turbocharged engines, providing improved performance. Air-conditioning was available as an option. The higher cost of this version of the Baron attracted only 93 sales, and production ended in December 1971.
The C55 became the D55 and finally the E55, Beechcraft’s high performance, high payload Baron. Optional equipment on the 58, E55 and B55 are heavy-duty brakes that offer up to 50 per cent greater stopping power.

Gallery

95-55
1960
Engines: 2 x Continental IO-470-L, 260 hp
Seats: 4-5
Sweptback fin and rudder

A55
1962
Optional 6th seat

BE-B55 Baron / T-42A Cochise
First built: 1961.
Engine: 2 x Continental IO-470-L, 260 hp.
TBO: 1500 hrs.
Prop: Hartzell 2 blade, constant speed 78 in.
Seats: 4/6.
Length: 28 ft.
Height: 9 ft. 7 in
Wingspan: 37 ft. 10 in
Wing area: 199 sq.ft.
Wing aspect ratio: 7.2.
Max ramp wt: 5121 lbs.
Max take off wt: 5100 lbs.
Standard empty wt: 3236 lbs.
Max useful load: 1885 lbs.
Max landing wt: 5100 lbs.
Wing loading: 25.6 lbs/sq.ft.
Power loading: 9.8 lbs/hp.
Fuel, std: 136 USG
Max useable fuel: 816 lbs.
Climb rate: 1693 fpm @ 107 kts.
Climb gradient: 949 ft/nm.
Rate of climb @ 8000 ft: 1000 fpm.
Service ceiling; 19,300 ft.
SE rate of climb: 397 fpm @ 100 kts.
SE climb gradient: 238 f/nm.
SE ceiling: 6400 ft.
Max speed: 201 kts.
Cruise @ 65% power @ 8,000ft: 180 kts.
Cruise speed, 8,000 ft 75% power: 188 kt
Fuel flow @ 65% power @ 8,000ft: 136 pph / 23.7 USgph
Fuel consumption 75% power: 27.3 USgph
Endurance @ 65% power @ 8,000ft: 5.7 hr.
Max range (w/ res) 75% power: 798 nm
Max range (w/ res) 65% power: 830 nm
Stalling speed clean: 79 kts.
Stall speed gear/flaps down: 73 kts.
Turbulent air penetration speed: 157 kts.
Retractable undercarriage.
Takeoff ground roll: 1400 ft
Landing ground roll: 1467 ft
Cabin width: 42 in
Cabin height: 50 in
Baggage capacity: 700 lb

C55
1964
Engines: 2 x Continental IO-520-C, 285 hp

D55
1968

E55
1970

Colemill Presidential 600 / Beech Baron B55
Engines: 2 x Continental IO-520-E, 300 hp.
Seats: 6.
Wing loading: 25.6 lb/sq.ft.
Pwr loading: 8.5 lb/hp.
Max TO wt: 5100 lb.
Empty wt: 3200 lb.
Equipped useful load: 1777 lb.
Payload max fuel: 925 lb.
Range max fuel/ 75% cruise: 1040 nm/4.4 hr.
Service ceiling: 19,700 ft.
75% cruise: 204 kt.
Vmc: 66 kt.
Stall: 66 kt.
1.3 Vso: 86 kt.
ROC: 2500 fpm.
SE ROC: 490 fpm @ 94 kt.
SE ceiling: 13,500 ft.
Min field length: 1840 ft.
Fuel cap: 852 lb.

C55
Engines: 2 x 285 hp Continental IO 520.
Fuel cap: 144 USG.

BE-E55 Baron
First built: 1966.
Engine: 2 x Continental IO-520-CB, 285 hp.
TBO: 1700 hrs.
Prop: Hartzell 2 blade, constant speed 78 in.
Seats: 4/6.
Length: 29 ft.
Height: 9.2 ft.
Wingspan: 37.8 ft.
Wing area: 199 sq.ft.
Wing aspect ratio: 7.2.
Max ramp wt: 5324 lbs.
Max take off wt: 5300 lbs.
Standard empty wt: 3291 lbs.
Max useful load: 2033 lbs.
Max landing wt: 5300 lbs.
Wing loading: 26.6 lbs/sq.ft.
Power loading: 9.3 lbs/hp.
Max useable fuel: 996 lbs.
Climb rate: 1682 fpm @ 101 kts.
Climb gradient: 999 ft/nm.
Rate of climb @ 8000 ft: 1000 fpm.
Service ceiling; 19,100 ft.
SE rate of climb: 388 fpm @ 100 kts.
SE climb gradient: 233 f/nm.
SE ceiling: 6600 ft.
Max speed: 208 kts.
Cruise @ 65% power @ 8,000ft: 190 kts.
Fuel flow @ 65% power @ 8,000ft: 161 pph.
Endurance @ 65% power @ 8,000ft: 6 hr.
Stalling speed clean: 83 kts.
Stall speed gear/flaps down: 73 kts.
Turbulent air penetration speed: 156 kts.
Retractable undercarriage.

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.

Forty L-23B [53-6153/6192] were purchased and a single XL-23C [55-3465] in 1955, converted to U-8G.

L-23 trials included “flying fuel tanks” to greatly increase fuel loads with the extra wing area attached to the tanks offsetting the greater weights involved.

Both civil and military versions continued to be developed through various marks. By 1955, 96 L-23As and Bs were built.

In 1958 the US Army sought an upgrade 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 conversion 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.

From the L23F derivative of the Model 50 Twin Bonanza Beech developed the civil Model 65 Queen Air with it first flying on 28 August 1958.

Gallery

B50
Cruise: 190 mph
Range: 1088 mi
Seats: 6

C50
Engines: two 275-hp Lycoming GO-480-F6
Wing span: 45 ft 3.5 ft
Wing area: 277.06 sq.ft
Length: 31 ft 6.5 in
Height: 11 ft 4 in
Gross Wt. 5500 lb
Empty Wt. 3800 lb
Fuel capacity 33 USG
Top 205 mph
Cruise 65%: 197 mph at 10,000 ft
Stall 64 mph
Initial climb rate 1450 fpm
Ceiling 20,000 ft
Range 920 sm
Takeoff distance (50’) 1350 ft
Landing distance (50’) 1210 ft
Seats 4-6

D50A-E
Engines two 295-hp Lycomings
Seats 6.
Gross Wt. 6300 lbs.
Empty Wt. 3981 lbs.
Fuel capacity 180 USG.
Top speed 214 mph.
Cruise 203 mph.
Stall 71 mph.
Initial climb rate 1450 fpm.
Ceiling 20,000 ft.
Range 1650 sm.
Takeoff distance (50’) 1260 ft.
Landing distance (50’) 1452 ft.

Beechcraft 1958 D50A Twin Bonanza
Engine: Lyc. GO-480G2D6, 295 hp
TBO: 1400 hr
Fuel type:100LL
Propeller: Const. spd.
Landing Gear type: Tri./Retr.
Gross weight: 6300 lb
Empty weight, std: 4090 lb
Useful load: 2210 lb
Fuel: 134 USgal
Payload, full std. fuel: 624 lb
Wingspan: 45 ft. 3 in.
Overall length: 31 ft. 6.5 in.
Height: 11 ft. 4 in.
Wing area: 277 sq. ft
Seating capacity: 7
Cabin width: 54 in
Cabin height: 51 in
Baggage capacity: 500 lb
Cruise speed, 8,000 ft 75% power: 203 kt
Cruise speed, 8,000 ft 65% power: 201 kt
Max range (w/ res) 65% power: 825 nm
Fuel consumption 70% power: 37 US gph
Fuel consumption 65% power: 34 US gph
Stall speed (gear, flaps down): 71 kt
Best rate of climb: two engines: 1450 fpm
Best rate of climb: one engine: 300 fpm
Service ceiling two engines: 20,000 ft
Service ceiling one engine: 7000 ft
Takeoff ground roll: 905 ft
Landing ground roll: 700 ft

Beechcraft E-50 Twin Bonanza
Business Twin, USA, 1957
Engine : 2 x Lycoming GSO 480 B1 B6, 316 hp
Length: 31.529 ft / 9.61 m
Height : 11.516 ft / 3.51 m
Wingspan : 45.21 ft / 13.78 m
Wing area : 276.958 sq.ft / 25.73 sq.m
Max take off weight : 4795.9 lb / 2175.0 kg
Weight empty : 5009.8 lb / 2272.0 kg
Max. weight carried : 1991.1 lb / 903.0 kg
Max. speed : 198 kt / 366 km/h
Initial climb rate : 1614.17 ft/min / 8.20 m/s
Service ceiling : 24606 ft / 7500 m
Wing load : 17.43 lb/sq.ft / 85.0 kg/sq.m
Range : 864 nm / 1600 km
Endurance : 5 h
Crew : 2+5

J50
Engines two 340-hp Lycomings.
Seats 6-7.
Gross Wt. 7300 lbs.
Empty Wt. 4460 lbs.
Fuel capaci.ty 230 USG.
Top speed 235 mph.
Cruise 223 mph.
Stall 82 mph.
Initial climb rate 1270 fpm.
Range 1650 sm.
Ceiling 29,150 ft.
Takeoff distance (50’) 1450 ft.
Landing distance (50’) 1840 ft.

Excalibur / Beech Twin Bonanza
Engines: 2 x Lycoming IGSO-540-A1A, 380 hp.
Seats: 6/7.
Wing loading: 22.7 lb/sq.ft.
Pwr loading: 9.6 lb/hp.
Max TO wt: 7300 lb.
Empty wt: 4768 lb.
Equipped useful load: 2200 lb.
Payload max fuel: 820 lb.
Range max fuel/ 75% cruise: 797 nm/3.5 hr.
Range max fuel / 55% cruise: 1343 nm/ 6.7 hr.
Service ceiling: 30,000 ft.
75% cruise: 226 kt.
55% cruise: 202 kt.
Vmc: 78 kt.
Stall: 72-78 kt.
1.3 Vso: 93 kt.
ROC: 1900 fpm.
SE ROC: 340 fpm @ 102 kt.
SE ceiling: 17,500 ft.
Min field length: 2612 ft.
Fuel cap: 1380 lb.

Excalibur Excalibur 800 / Beech Twin Bonanza
Engines: 2 x Lycoming IO-720-A1B, 400 hp.
Seats: 6/7.
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

YL-23

L-23A
Engines: 2 x 260hp O-435

L-23B
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.
Sats: 6
Range: 985 miles at 190 m.p.h.

XL-23C

L-23D / E/F-50 / U-8D / RU-8D / RU 8D Seminole
1958
Engines: 2 x 340hp O-480
Useful load: 2026 lb
Max speed: 233 mph
Cruise speed: 203 mph
Range: 1355 mi
Seats: 6
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.

RL 23D
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].

U-8G Seminole
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].

The Beechcraft Model 40A was an experimental twin-engine aircraft based on the Bonanza. Only one prototype was built in 1948. It featured a unique over/under arrangement of two 180-hp Franklin engines mounted on top of each other and driving a single propeller.

The plane had a different engine cowl from a standard Bonanza, and the nose gear could not fully retract, but otherwise it greatly resembled the production Bonanzas of the time.

Certification rules demanded a firewall be fitted between the two engines, however, thus stopping development.

The status of the prototype is unknown.

The Twin Quad was an unpressurized, 20-passenger entrant into the feeder-line market. The name ‘Twin Quad’ came from the two horizontally-opposed, 400hp (300kW) Lycoming GSO-580 engines buried transversely in each wing to drive a single propeller through a common gearbox. The Twin Quad also had a V-tail similar in shape to that of the Bonanza. The first flight of the prototype was on October 1, 1947, at Wichita, Kansas. Following more than a year of flight testing, it was damaged beyond economical repair in a forced landing. By then, Beech had learned that the feeder-line market could not support a new design. Even had there, the unique powerplant installation would have required considerable development to achieve the reliability needed for airline service.