In 1968, Beech Aircraft Corporation engineers employed their airframe “cookbook” to create the versatile Model 58 Baron, followed later by the turbocharged 58TC and the pressurized 58P.
By the late 1960s, the Beechcraft Model 55 series “Baron” and the muscular Model 58TC had proven to be highly successful additions to the company’s product line. It had begun in 1960 with introduction of the Model 55 that eventually replaced the aging Model 95 Travel Air that had entered production in 1956 and continued to be manufactured until 1968.
Although the Model 95 series was well received by Beechcraft dealers and customers, the Model 55 was a thoroughly modern lightweight, twin-engine Beechcraft that met the demands of a constantly evolving market. By 1971 more than 2,300 of the twin-engine Baron series had been built, attesting to its solid popularity.
Throughout the 1960s, Beech Aircraft was faced with stiff competition from Piper Aircraft Corporation’s turbocharged Aztec and Cessna Aircraft Company’s family of 400-series airplanes such as the unpressurized Model 401 and 402 and later the pressurized Model 414 and Model 421. Gradually, Beechcraft dealers and distributors began to clamor for a larger Baron, one that would compete head-to-head with Piper and Cessna in terms of cabin size, comfort and performance.
As always, company President Frank E. Hedrick and Chairman of the Board Olive Ann Beech listened to what their salesmen were saying. During regional sales meetings held in 1969 in Phoenix, Arizona; Dallas, Texas; and Atlanta, Georgia; company officials unveiled plans for the 1970 model year lineup that included the Model 100 King Air – the first evolution of the venerable turboprop-powered Model 90 that had increasingly dominated the turbine-powered business aircraft market since its introduction in 1964.
The major news, however, for salesmen, owners and operators of the Model 55 Baron series was the announcement that the Model 58 Baron would be available for delivery in 1970. According to Beech Aircraft Corporation historian William H. McDaniel, “This new version of general aviation’s fastest light twin featured a lengthened fuselage offering ample, airline comfort seating for six people, or corresponding optional loads of cargo or passengers. Double rear doors almost four feet wide facilitated loading of passengers or bulky cargo. Designed to meet the specific need of many business users, the Baron 58 was clearly a model with a very substantial sales potential.” 1
In the late summer of 1968, Beech Vice President of Marketing Roy H. McGregor, Vice President Jack L. Marinelli, aircraft research and development, and long-time Beechcrafter James N. Lew, vice president of engineering, had ordered design studies that centered on stretching the fuselage and cabin of the Model 55, adding more windows (similar to those installed in the Model A36 Bonanza) and lengthening the nose section 10 inches to more easily accommodate that loading and unloading of baggage.
To set the Model 58 apart from its smaller sibling, increasing interior volume was of major importance. To achieve that goal, the new Beechcraft featured an instrument panel that was located farther forward than that of the Model E55. The right-side cabin door and the two front seats also were moved forward. These three major modifications were achieved without having to relocate the wing itself and the main wing spar, which would have entailed major retooling and higher production costs.
Having received the green light from the front office to proceed with the design, construction of the first pre-production prototype was underway early in 1969 and was completed four months later. First flight occurred on June 23 of that year, followed in November by first flight of a production airplane. On November 19, 1969, the FAA approved the Model 58 under an amended Type Certificate (TC) 3A16 – the same TC issued for the Model 55 series, as well as the Model 56TC and A56TC.
To power the Model 58, engineers chose the reliable Continental IO-520-C rated at 285 horsepower. The six-cylinder, fuel-injected powerplant was similar the IO-520-C engines that equipped the Model 95-C55. The Baron’s engines turned McCauley two-blade propellers that featured constant-speed and full-feathering capabilities (three-blade propellers were available as an option). The Model 58 also featured redesigned cowlings and propeller shafts that were extended forward to improve cylinder cooling.
The cabin interior was carefully planned to take advantage of the 135.9 cubic feet of volume provided by reconfiguring the cockpit area. The large double doors located on the right side of the fuselage allowed easy entry/egress from the cabin as well as loading and unloading of light cargo with the four passenger seats removed. The standard cabin seating configuration included four seats facing forward, but a club seating arrangement with the third and fourth seats facing aft proved to be a popular option but was not made available until serial number TH-35. In addition, customers could order fifth and sixth folding seats, but these were best suited only for children or small adults.
The forward baggage compartment accommodated up to 300 pounds of luggage or light cargo, and was accessible through a hinged door forward of the windshield. The compartment also provided about seven cubic feet of space to mount remote avionics components. With all passenger seats removed, the main cabin floor was rated for up to 400 pounds. An additional 120 pounds could be placed in a recess located in the aft cabin area.
The Baron 58’s airframe featured standard all-metal Beechcraft construction with a semi-monocoque fuselage (length 29 feet 10 inches) and a cantilever empennage equipped with dual trim tabs on the elevators and one on the rudder (span was 15 feet 11 inches). Manually-operated pitch trim was standard, but electric pitch trim was an option (few, if any, airplanes left the factory without an autopilot that incorporated electric pitch trim). The wings, which spanned 37 feet 10 inches, featured the NACA 23016-5 airfoil at the wing root that tapered to NACA 23010-5 at the tip, with six degrees of dihedral and an incidence of four degrees.
The wing panels gained their strength from double-spar, box-type aluminum alloy construction fitted with single-slotted trailing edge flaps that were operated electrically. The ailerons were of corrugated aluminum alloy, but only the left aileron was equipped with a trim and balance tab. The electrically-operated tricycle landing gear was essentially identical to that of the E55 Baron except that the wheelbase was increased slightly to improve grand handling characteristics.2
As for performance, the Model 58 had a maximum cruise speed of 200 knots (230 mph or 370 km/h) at an altitude of 7,000 feet and a 75 percent power setting. Speed decreased to 162 knots at 12,000 feet with power set to 45 percent. Twin engine rate of climb was 1,695 feet per minute at sea level, or 382 feet per minute with one engine inoperative at sea level at a maximum gross weight of 5,400 pounds.
The only Model 58 built for the 1969 model year was serial number TH-1, but the factory in Wichita, Kansas, built 98 Model 58 Barons for the 1970 model year (serial numbers TH-2–TH-94, TH-96–TH-98 and TH-101–TH-102).3 A standard-equipped Model 58 sold for $89,850. Among the more salient upgrades made during the first model year of production were new Slick magnetos for the IO-520-C engines, improved cabin door seals, optional three-blade propellers; propeller deicing capability, and optional fuel tanks holding 166 gallons (136 standard).
The Model 58 proved to be popular as an owner-flown, lightweight twin-engine Beechcraft. For the 1971 model year, 75 airplanes were built, followed in 1972 with 89 units and another 121 were built in 1973. By that time the price had climbed to $108,850 for a standard-equipped airplane. The 1979 Baron 58 featured Continental IO-520-CB engines, still rated at 285 horsepower each, that incorporated a new crankshaft (change effective with serial number TH-973). The next year a new exterior paint design was applied and the cabin interior was restyled. In addition, an electrically-heated windshield was available for the first time.
The 1984 Model 58 featured a number of major upgrades including a redesigned interior and exterior paint scheme, a new instrument panel and instrumentation, and installation of a dual control system that finally eliminated the throw-over control column that had been in use since the early production Model 17 biplane. Another important upgrade was installation of Continental IO-550C engines, each rated at 300 horsepower. As of 1984, Beech Aircraft had produced more than 1,400 examples of the Baron 58, but only 41 airplanes were built that model year. The price for a standard-equipped Model 58, however, had escalated to $315,000. By 1986, more than 1,500 examples of the Baron 58 had been built and market demand remained strong.
Production continued unabated through the 2004 model year, although the number of units manufactured declined steadily. For example, 41 were built in 1984, 69 in 1985, three in 1986 and 24 in 1987. During the span of 1986 through 1993, only 176 airplanes were built, but the standard-equipped price had skyrocketed to $571,800 for the 1993 Baron 58 from $356,500 for the 1985 version.
In 2005, the Model 58 was upgraded to the G58 (current production model). Overall, this latest version of the venerable Beechcraft has changed little from its predecessors with only minor upgrades to the airframe and systems, including Continental IO-550-C engines each rated at 300 horsepower. A major improvement, however, was installation of the Garmin G1000-series digital, fully-integrated avionic architecture to help keep pace with the competition. The G58 has a maximum range of 1,480 nautical miles, a useful load of 1,494 pounds and a maximum cruising speed of 202 KTAS. As of early 2017, the G58 remained in production selling at $1.4 million for a standard-equipped airplane. According to Beech Aircraft’s parent company Textron Aviation, 309 G58 were delivered during the 2015-1016 model years.
In the wake of the Model 58’s success, in 1976 Beech Aircraft introduced the six-place, turbocharged Model 58TC, priced at $170,750 (before options). The chief modification was trading the Continental IO-520-C engines for the six-cylinder, turbosupercharged, injected, opposed (TSIO) Continental IO-520-L powerplants each rated at 310 horsepower at 2,600 RPM. Each engine was equipped with three-blade propellers featuring constant-speed operation and full-feathering capability. First flight of a pre-production airplane occurred on October 31, 1975.
Long-time Beechcraft salesman and historian Larry A. Ball maintained that the 58TC was “probably certified and offered on the market for only two reasons. First, the engine installation already was under development for the pressurized Model 58P, and second, competitors Piper Aircraft Corporation and Cessna Aircraft Company were offering unpressurized, turbocharged airplanes” (such as the Piper Aztec F and Cessna Model 402, respectively).
Unfortunately, the 58TC failed to achieve the popularity of the Baron 58 series and “never enjoyed wide acceptance,” Ball said. During nine years of production only 151 were built, but a 1977 Model 58TC did achieve some degree of fame when it became the 40,000th Beechcraft manufactured since the Model 17R cabin biplane of 1932.4
Dimensions and performance were similar to the Model 58, with a maximum speed of 249 knots, range (with 190 gallons of useable fuel) 968 nautical miles at an altitude of 20,000 feet, and a service ceiling of more than 25,000 feet. Maximum ramp weight was 6,140 pounds, decreasing to maximum takeoff weight of 6,140 pounds (after fuel burn for startup and taxi).
For the 1976 model year, Beechcrafters built 34 examples of the 58TC beginning with serial number TK-1. The 1977 version remained unchanged, and 26 units were manufactured followed in 1978 by 24 units. Polyurethane paint became standard on the 1979 58TC that also featured more powerful Continental TSIO-520-WB engines, each rated at 325 horsepower (possibly in response to Cessna’s 1979 Model 402C upgrade that included Continental TSIO-520-VB engines each rated at 325 horsepower). Standard-equipped price increased to $206,650, and only 25 airplanes were built that year.
From the 1980 model year to 1984 only 42 of the turbosupercharged Beechcrafts were built, including four in 1982 and one each in 1983-1984. The final Model 58TC built was serial number TK-151 that was the only 58TC to have the new, dual-control installation and new instrument panel design that also was used in the Model 58 and 58P. When the last 58TC rolled off the assembly line, base price had risen to $284,500 compared to $170,750 for the first production 58TC.
In an attempt to keep pace with competition from Cessna’s twin-engine, pressurized Model 421 (introduced in 1968) and later the Model 421B Golden Eagle that was unveiled in 1973, as well as other competitors, Beech Aircraft officials believed it was necessary to offer customers a pressurized version of the Model 58TC. It should be noted here that Piper built and flew a PA-41P pressurized Aztec in 1974, but the engineering proof-of-concept airplane (serial number 41P-1, registered N9941P) was not developed. The PA-41P was powered by two Lycoming TIO-540 engines each rated at 270 horsepower. After flight tests were terminated, the airplane eventually was donated to the Mississippi State University.5
Within the hallowed halls of “Mahogany Row,” discussion about whether to move forward with the Model 58P was not without its share of internal controversy. The chief point of contention between marketing and engineering executives centered on the Model 60 “Duke” that, as of the early 1970s, was selling reasonably well. The six-place, dramatically-styled Duke was aimed directly at Cessna’s highly successful Golden Eagle, but because of the Duke’s sleek fuselage design, its cabin was smaller and less comfortable that that of the Model 421B. A few people, including Larry A. Ball, opposed developing the Model 58P because he believed the Duke already filled the 58P’s proposed market niche.6
Many years later, Ball explained the situation this way: “Basically, my main argument was we already had a pressurized Baron, only it was called the Beechcraft Duke. I argued that we already had essentially what they were after.” Despite his “reasoned” presentation to all concerned, he lost the battle. The Baron 58P proposal was approved. Ball later commented that “when marketing has made up their mind and engineering is willing to tell them what they want to hear, manufacturing will usually lose the argument.”
An engineering prototype of the Model 58P first flew on August 16, 1973. After the flight test program was complete, the FAA granted certification on May 21, 1974. The 58P was powered by two Continental TSIO-520-L engines each rated at 310 horsepower. Bleed air from the turbosuperchargers was routed to the cabin and provided a maximum differential of 3.6 pounds per square inch (psid). At maximum differential, the system kept the cabin altitude at sea level up to a flying altitude of about 8,000 feet. Flying at 18,000 feet, the 58P’s cabin altitude was 7,700 feet and increased to 10,000 feet at a cruising altitude of 21,200 feet.
At 25,000 feet, the 58P cruised at 213 knots and at that altitude with 190 gallons of useable fuel, could fly 1,086 nautical miles. Rate of climb (two engines) at sea level was 1,413 feet per minute (fpm), while rate of climb with one engine inoperative (sea level) was 205 fpm decreasing to 172 fpm at an altitude of 5,000 feet. Maximum takeoff weight was 6,100 pounds with a useful load of 2,155 pounds (standard-equipped airplane). Pneumatic deice systems for the wings, empennage and propellers were standard. Base price of the Model 58P during the 1976 model year was $200,750, and 83 units were built beginning with serial number TJ-3.
For the 1979 model year the 58P received upgraded engines – Continental TSIO-520-WB each rated at 325 horsepower (serial numbers TJ-169-TJ-234 were approved for installation of the new engine, except for TJ-210). Maximum speed increased slightly to 261 knots (300 mph). Other upgrades included a new exterior paint design, major improvement to cabin interior appointments, and maximum cabin pressure differential increased to 3.9 psid from 3.7 psid. The factory at Salina, Kansas, built 65 units in 1979. A standard-equipped Model 58P carried a base price of $250,000.
Production continued unabated through the remainder of the 1970s, with 83 units built in 1980, 68 in 1981 and 47 in 1982. Manufacture plummeted to only 11 in 1983 as base price increased to $384,650. The final version of the 58P was built for the 1985 model year when 27 were manufactured. Base price increased to $473,000. During a production life of nine years, a grand total of 495 airplanes were built.7
Based on production of all three Baron models built from 1976-1985, the Model 58 by far proved to be the most popular with Beechcraft owners and operators worldwide. As of late 2016, 2,124 had been built since 1970. The Model 58’s combination of performance, utility, comfort and reliability helped to keep it rolling off the assembly line for more than 45 years.
Notes:
- McDaniel, William H.: “The History of Beech;” McCormick-Armstrong Co., Inc., Wichita, Kansas, 1982.
- Taylor, John W.R.: “Janes All The World’s Aircraft 1972-73;” Jane’s Yearbooks, McGraw-Hill Book Company; Sampson Low Marston & Co., Ltd.
- Ball, Larry A.: “From Travel Air to Baron – How Beech Created A Classic!” Ball Publications, Indianapolis, Indiana, 1994.
- Phillips, Edward H.: “Pursuit of Perfection – A History of Beechcraft Airplanes;” Flying Books, Eagan, Minnesota, 1992.
- Phillips, Edward H.: “Piper – A Legend Aloft;” Flying Books International, Eagan, Minnesota, 1993.
- Ball, Larry A.: “From Travel Air to Baron – How Beech Created A Classic!” For purposes of comparison, from 1968-1982 Beech Aircraft built a total 596 examples of the Model 60-series Duke, while Cessna Aircraft Company produced a grand total of 1,923 units of the Model 421 beginning in 1968 and terminating in 1985.
- The unofficial term “Mahogany Row” applied to the walls of mahogany paneling that lined the corridor within Beech Aircraft’s main administration building. Senior company executives, including Olive Ann Beech, had their offices located there.
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