The Best Bonanza Ever?

Starting with the Model E33A, in 1968 Beech Aircraft engineers dug deep into their airframe “cook book” to create the company’s most popular and versatile Bonanza – the Model 36 series.

“The biggest, most versatile Bonanza ever built.” That was how Beech Aircraft Corporation described the new Model 36 Bonanza when it was certified in May 1968. Introduced to company dealers and distributors on June 18, by the end of the year, sales of the six-place Beechcraft had soared to more than $3.5 million. Standard equipped price was $40,650.¹

During those months, the production line was kept busy as orders for Model 36 poured in from Beechcraft’s global sales organization. When workers went home to celebrate the 1968 Christmas season, they had built 105 airplanes. In addition, increasing demand for the new multi-mission Bonanza would keep Beechcrafters busy throughout 1969.

From the beginning of the Model 36 design and development program, the airplane was aimed directly at three markets: air taxi, light cargo and private aviation, with an emphasis on the first two. Unlike some of its siblings such as the twin-engine Model 55 Baron, the latest Beechcraft was not answering competition from Cessna Aircraft Company or Piper Aircraft Corporation – neither had a single-engine, retractable-gear airplane that could accommodate six people. The Cessna Model 210 was a four-place design, and Piper’s twin-engine Aztec was in a different class entirely than the Model 36.

The Beech Aircraft engineering department, led by Vice President James Lew, used the Model E33A Bonanza as a starting point and relocated the rear cabin bulkhead 19 inches farther aft (also similar to that of the Model V35A Bonanza) and stretched the E33A’s fuselage 10 inches. As a result, distance from the cabin’s forward bulkhead to the aft bulkhead increased by 29 inches. Cabin volume increased by six cubic feet, and the modification only increased empty weight by 31 pounds.

Compared to the Model S35, V35 and the V35A, the Model 36 fuselage being 10 inches farther forward over the wing, resulted in a much more flexible center of gravity (CG) envelope. The new Bonanza could easily accommodate six 170-pound occupants and remain within the specified CG envelope based on a standard-equipped airplane. Another benefit of stretching the fuselage was a 10-inch increase in landing gear wheel base, making the airplane easier to maneuver on the ground.

Another significant feature centered on making access to the main cabin easy, particularly for air taxi operators who wanted the ability to remove the aft four seats and carry lightweight cargo if required. To provide that access, engineers designed a four-foot wide double door located on the right side of the fuselage. The doors, constructed of bonded honeycomb for strength and light weight, could be removed for flight although airspeed and other restrictions applied. The ability to remove the doors made the Model 36 an attractive platform for aerial photography. Air taxi operators also liked the Bonanza’s FAA certification in the Utility Category at the maximum gross weight of 3,600 pounds, as well as its cruise speed of 195 mph that placed it among the fastest six-place, single-engine lightweight transports in that market segment.²

The choice of a powerplant for the Model 36 would be the ubiquitous six-cylinder Continental IO-520-B. Rated at 285 horsepower, the reliable engine also powered the Model V35 and V35A Bonanza. Early production versions of the Model 36 featured a utilitarian interior that was not well received by some Beechcraft customers accustomed to the well-appointed cabin of the V35. The company did, however, offer a deluxe interior in addition to the standard and utility versions that were designed for the rugged environment of air taxi operations.

During the 1969 model year, 79 of the versatile Model 36 were built. Salient upgrades included (but were not limited to):

• A third latch on the cabin door beginning with serial number E-4
• A more powerful flap motor on E-106 and all subsequent airplanes
• Quick release pins for fifth and sixth seats in the aft cabin, first installed on E-146
• A Prestolite alternator replaced the Delcontron unit beginning on E-124
• The Narco Mark 16 radio replaced the aging Narco Mark 12 (digital avionics were not yet available)
• Heat and cold air ductwork were rerouted for improved air circulation. First installed on E-106.

For the 1970 model year, Beech Aircraft officials paid attention to feedback from salesmen and operators calling for more upgrades to the airplane that would essentially make it a six-seat equivalent of the V35B – the company’s single-engine flagship. There was, however, a problem of how the new Bonanza was perceived by operators.

Bonanza historian Larry A. Ball summed up the situation this way: “The original Beech factory approach to marketing the Model 36 was to advertise it as an aerial moving van, an air taxi, a carry-all and an ideal charter airplane for the fixed base operator. Although the Model 36 was all of these, the [company’s] marketing approach did not sell many airplanes.”³ Although Beechcraft dealers were eager to sell the Model 36, a key disadvantage was that most of air taxi and charter operators were already dealers for Cessna and Piper airplanes, and they were not inclined to buy a Beechcraft.

As a result, it was decided to give the airframe a “make-over,” a new look that would bring it up to V-tail Bonanza and Baron standards, both inside and out. Perhaps more importantly, the advertising shifted emphasis to the owner-flown segment of the market – a group that had purchased so many Bonanzas over the years. The changes that occurred demanded a new designation, and the Model A36 was born.

The A36 boasted a litany of improvements from a much more aesthetic, eye-catching exterior paint design, a luxurious interior with a choice of leathers, three green landing gear “DOWN” annunciator lights instead of one used on earlier aircraft; Hartwell quick-release cowl latches, redesigned instrument subpanels, engine and fuel quantity indicators used on the Model 55 Baron, optional internally-lighted flight instrumentation, and electroluminescent components that provided improved lighting for night flying.

These and other changes increased empty weight to 2,023 pounds from 1,980 (including standard avionics), but performance remained the same with a maximum speed of 204 mph, range of 530 statute miles with 50 gallons of useable fuel (980 miles with optional 80-gallon capacity), and service ceiling of 16,000 feet.

As was the usual custom, further improvements were made during 1970-1972 as the A36 established itself as the “Rolls-Royce” of six-seat, high-performance single-engine airplanes in the general aviation industry. A sampling includes:

• Wing tips used on the V35B were adopted to the A36, increasing wing span to 33 feet six inches from 32 feet 10 inches
• Thicker Plexiglas on the pilot’s side window
• Self-exciting alternator (no longer required two dry cell batteries to excite the alternator field coils)
• Rotating beacon mounted on top of vertical stabilizer
• Anti-slosh fuel cells that prevented momentary loss of fuel flow during slips, skids and turning takeoffs with low fuel level in the tanks
• Optional club seating (center two seats facing aft, rear two facing forward) became available beginning with serial number E-221
• From E-226 onward, a relay was added to the landing gear electrical circuit that prevented illumination of the three green landing gear “DOWN” annunciator lights until the gear motor had completed its operating cycle
• Exterior decals were replaced by metal placards on production airplanes beginning with E-243
• The Narco Mark 12 radio (standard equipment) was replaced with a King KX-170 unit on E-244 and all subsequent airplanes
• Cabin seats and the instrument panel were revised for the 1972 model year, providing a slight increase in head room
• Redesigned ventilation system to increase volume of airflow and to reduce noise
• Electrically-operated, vertical-readout engine instruments introduced on the 1971 V35B
• Empty weight increased to 2,040 pounds from 2,023 pounds

Production of the A36 during the 1970-1971 model years began with E-185 and ended at E-282 – 98 units. Base price started at $42,950, but in August 1970 increased to $45,550.

As sales of the A36 continued into the late 1970s there was a growing, albeit small, movement toward a turbocharged version of the A36. Beech Aircraft had long been familiar with the advantages of turbocharging, and in the 1966 model year the company offered the Bonanza V35TC. With a base price of $37,750 and powered by a Continental TSIO-520-D engine rated at 285 horsepower, the artificially-aspirated Bonanza could maintain maximum manifold pressure all the way up to an altitude of 19,000 feet.

As expected, performance increased significantly, with a maximum speed of 250 mph at 19,000 feet compared with 210 mph for the naturally-aspirated Model V35. Production of the V35TC continued into the 1967 model year, and 79 were built before production changed to the V35A-TC, of which 49 were manufactured during the 1968-1969 model years. The last turbocharged version of the V-tail Bonanza was the 1970 V35B-TC that cost $45,250. Only seven were built and none were produced during 1971.

After a nine-year absence, turbocharging returned to the Bonanza family of Beechcrafts with introduction of the A36TC in 1979. The company may have been motivated to revisit the concept of a turbocharged A36 thanks to the popularity of Cessna’s Turbo Stationair 7, T210N Centurion and Piper’s new PA32-301T turbocharged Saratoga that was certified in January 1980.

Built initially for the 1979 model year, the A36TC was powered by Continental’s TSIO-520-UB engine that developed 300 horsepower. Cowl flaps were eliminated in favor of air cooling louvers that caused cooling problems for certain cylinders during the flight test program, but these were eventually resolved and the airplane received FAA certification on December 7, 1978, under (amended) Approved Type Certificate 3A15. An oxygen system was available and the cabin heating system was improved to provide 20 percent more heat at the turbo Bonanza’s maximum certified altitude of 25,000 feet.

The A36TC was well received by pilots, but they had to closely monitor cylinder head temperatures and mixture during climbout to avoid having to “step-climb” the airplane due to high cylinder head temperatures. Beech Aircraft established a special training course to familiarize pilots with the airplane’s characteristics, particularly if they were new to turbocharging. If, however, pilots flew the A36TC in accordance with procedures they were taught and specified in the Pilot’s Operating Handbook, the airplane was a strong performer and a welcome addition to the Bonanza lineup. During the first year of production, 32 airplanes were built followed in 1980 by 126 and another 113 in 1980 – the last year of manufacture for the A36TC.

During 1980-1981, Beech engineers reworked the A36TC into the improved Bonanza B36TC. It incorporated a series of upgrades to the airframe and engine including:

• Continental TSIO-520-UB engine rated at 300 horsepower
• New instrument panel featuring separate control wheel shafts (the iconic, 1940s-vintage Beechcraft throw-over control column was finally eliminated)
• Throttle, mixture and propeller controls were grouped into a quadrant located in a console between the two front seats
• Circular engine instruments similar in appearance to those installed in the King Air product line were mounted vertically
• Fuel capacity was increased 108 gallons total (102 useable)
• Wingspan increased to 37 feet 10 inches from 33 feet six inches
• Wedge-like vortex generators were installed in specific locations on the wing leading edge to improve roll control at high angles of attack
• The engine/turbocharger installation was improved
• Air conditioning was available as an option
• Maximum takeoff weight increased to 3,850 pounds

At a power setting of 31 inches Hg manifold pressure at 2,400 RPM (maximum power setting), the B36TC could cruise at 200 knots true airspeed (TAS, ISA conditions) at 25,000 feet. The first and only airplane built in 1981 was serial number EA-242. Another 50 were built in 1982 followed by 65 in 1983. The factory manufactured only 139 airplanes during the 1984 through 1992 model years. According to Textron Aviation, production of the B36TC ended in 2002 after a total of 424 airplanes had rolled off the assembly line since 1981.⁴

The current production version of the venerable Model 36 series is the Bonanza G36, first introduced for the 2005 model year. Priced at $800,000 for a standard-equipped airplane, the G36 ushered in the era of flat panel, fully-integrated avionics by featuring the Garmin G1000 system. As of 2017, production airplanes have the improved G1000nxi version. The system includes the GFC700 autopilot that replaced the G1000/Bendix/King KAP 140 found in some early G1000 systems. Other features include synthetic vision, XM weather and WAAS precision instrument approach capability.

In 2012, the G36 and its G58 Baron sibling were given a new interior with more comfortable seating, and an improved cabin environmental system was installed that provides air inlets for all occupants, not just in the cockpit as on previous aircraft. The G36 also features a 28 VDC electrical system fed by dual alternators and electrical buses that automatically tie together when the engine exceeds 2,000 RPM. According to Beechcraft parent company Textron Aviation, the Bonanza G36 has a maximum range of 920 nautical miles, maximum cruise speed of 176 knots and a useful load of 1,038 pounds. Takeoff roll (sea level, standard day) is 962 feet.

The author was among flight instructors at the Beechcraft Training Center that conducted ground-based courses and familiarization flights aimed at teaching pilots new to the B36TC how to manage the turbocharger system. In my opinion, the B36TC was a major improvement over the A36TC and possessed excellent flight characteristics, but cylinder head temperatures still had to be monitored closely during extended climbs, particularly on a hot day. As of early 2017, prices for a pre-owned B36TC varied from about $400,000 for a late production airplane with less than 1,200 hours total time, to $189,000 for an early production version with more than 3,000 hours total time.

As the Model 36 series enters its 50th year of production in 2018, the versatile Beechcraft will continue to be one of the company’s most popular airplanes. Despite its extraordinary price tag for a single-engine machine, the G36 offers pilots an attractive combination of speed, value, quality and utility that should keep it in production for years to come.

NOTES:

1. By comparison, in 1977 when the author went to work at the Beech Aircraft factory as a Bonanza marketing representative, base price for a Model A36 had increased to $105,000. As of early 2017, sticker price for a base Model G36 with typical options is $900,000.
2. Cruise speed based on a power setting of 75% at an altitude of 6,500 feet and full throttle (2,500 RPM). It is interesting to note that the 2017 G36 offers essentially the same performance as the original Model 36, but features a plethora of upgrades made during nearly 50 years that set it far apart from its 1968 ancestor.
3. Ball, Larry A. “Those Incomparable Bonanzas;” McCormick-Armstrong Company, Inc. Wichita, Kansas, 1971.
4. According to Textron Aviation, as of early 2017 its subsidiary Beech Aircraft Corporation had manufactured more than 4,700 of the Model 36 series, including the A36, G36, A36TC and B36TC.