During more than 30 years of production, the Beechcraft Model 18 series distinguished itself in peacetime and in war, emerging as one of the most successful small, twin-engine transports in aviation history.
Beech Aircraft Corporation test pilot H.C. “Ding” Rankin eased both throttles forward as the latest version of Ted Wells’ Model 18 accelerated down the runway. Sitting in the right seat, and acting as Rankin’s co-pilot, was none other than Walter H. Beech himself. Beech scanned the engine gauges for any signs of trouble as the sleek Model 18S gained airspeed. Rankin eased the control column forward as the tail came up to takeoff attitude and the ship continued to accelerate. Moments later the Beechcraft’s wings were full of lift, leaving terra firma behind for the blue skies above. “Gear up!” hollered the pilot, and Beech complied, but kept a close watch on the engine gauges to make sure all was well with the two Pratt & Whitney radial engines.
January 6, 1940, was a cold, snowy day. Beech and Rankin had just departed Lambert Field in St. Louis, enroute to Miami, Florida, where they hoped to capture the Macfadden Trophy. The race presented Walter Beech with a splendid opportunity to demonstrate the latest Beechcraft’s capabilities to the aviation world and the public. Although he spent a majority of his time flying a desk as president of the company, Walter had racing in his blood and his thirst for speed was insatiable.
The Model 18S was the first “Twin Beech” to feature the R-985 static, air-cooled radial engine that was rated at 450 hp. Previous versions, including the Model 18A, 18B and 18D built in 1938-1939, were powered by Wright Aeronautical R-760, Jacobs L-5 or L-6 radial powerplants. Initially developed in 1929, the R-985, also known as the “Wasp Junior,” was designed by Connecticut-based Pratt & Whitney as a direct competitor to the R-975 built by Wright Aeronautical Corporation located in Paterson, N.J. Both engines featured nine cylinders and similar displacement. The R-985 produced 450 hp at 2,300 RPM, with a cylinder bore and stroke of 5.2 inches and a dry weight (no oil or fuel) of 653 pounds. Thousands of R-985s were built during the war, many of which would find their way onto the wings of military Model 18 Beechcrafts.1
As for Beech and Rankin, they flew the Model 18S to victory by covering the 1,084 nautical miles between St. Louis and Miami in four hours, 37 minutes, at an average speed of more than 234 mph. Up to that time, it was the fastest speed recorded by a licensed commercial airplane during an event sanctioned by the National Aeronautical Association. As Beechcraft Model 18 historian Robert K. Parmerter recalls, “the R-985 engines were operated at 52 percent of their rated 450 hp for the duration of the race, and although 330 hours had been logged on each engine up to that time with only routine servicing, total oil consumption was a mere 1.5 quarts,” whereas the engines gulped 208 gallons of aviation fuel.2
Second-place pilot Russell Holderman was flying a twin-engine Lockheed Model 12-A. The “Beech Boys” collected the tidy sum of $3,000 for their efforts, and a few days later the Model 18S won the Congress Cup Race flown between Miami and Havana, Cuba, covering the distance in only 59 minutes and setting a speed record for that route.
The Model 18S possessed a number of key changes not found in the current production airplane, the Model 18D. Ted Wells and his engineering staff began work on the upgrades in 1938. As mentioned, chief among these was adoption of the Pratt & Whitney R-985. In addition, new, more streamlined cowlings were designed that included cowl flaps fitted to the lower half of each cowl. Another salient change centered on the two vertical stabilizers that were enlarged compared to the original configuration.
Wells and his team also improved operation of airframe systems and subsystems such as flight controls, heating and the main landing gear. Lastly, thickness of the wing skin was increased. The higher horsepower of the engines coupled with technical improvements allowed a maximum gross weight increase to 6,700 pounds from 6,500 pounds. These airframe changes applied to all Model 18S built regardless of what type of engines were installed.3
Back in 1937, production of the Model 18A had been slow to start, with only six airplanes built that year. It is important to note, however, that the factory delivered only one airplane that year – the Model 18 prototype, constructor number 62 registered NC15810. Feedback from initial operators of the new Beechcraft led to development of the improved Model 18B and 18D. The former were powered by the Jacobs L-5 radial engine rated at 285 hp, whereas the latter featured Jacobs L-6 engines rated at 330 hp. The L-6 was a new engine and helped to boost sales of the Model 18D, particularly to customers who preferred the more powerful engine. The first of that version was built in May 1938. The interior appointments, in terms of fabric material, color and texture, were often selected or suggested by Olive Ann Beech.
Despite the improving economic conditions in the United States by 1938, selling the Model 18 proved difficult. Operators were hard pressed to come up with as much as $37,000 for the new Beechcraft, and many business executives remained unconvinced that airplanes could be an effective tool for increasing their business. During the years 1937-1940, only 28 twin-engine Beechcrafts were delivered. The winds of war, however, were beginning to blow with more intensity across Western Europe as Germany’s Fuhrer, Adolph Hitler, increasing his saber-rattling rhetoric while building up the Third Reich’s powerful army, navy and air forces. In addition, diplomatic relations between Washington, D.C., and the Japanese capital of Tokyo were becoming increasingly strained as the Nipponese military flexed its aggressive muscle in Manchuria and China while casting a lustful eye on the rich oil fields of Indonesia.
The Nazi invasion of Poland in September 1939 led to Great Britain and France honoring their obligation to defend Poland by declaring war on Germany. In the wake of that declaration, American opinion was steadfastly against involvement in that conflict, but as time wore on, it was becoming obvious that the United States would be drawn into the war. Any doubts about that probability were brutally dashed on December 7, 1941, when the Imperial Japanese Navy crippled the American Pacific Fleet at Pearl Harbor.
By 1940, with the war going badly for Great Britain and France, both of which entered the fray woefully unprepared to confront Hitler’s modern and well-equipped war machine, the United States slowly began to rearm its own military forces. President Roosevelt was committed to helping the British by declaring America the “arsenal of democracy.” Beech Aircraft Corporation (BAC) and other small aircraft manufacturers played a vital role in the United States’ rearmament initiatives. Walter and Olive Ann Beech knew that if the nation went to war, their company would be called upon to produce aircraft for the cause of freedom.
When Roosevelt signed the National Defense Act of 1940, $300 million was made available for the specific purpose of buying 6,000 aircraft for the Army Air Corps and to increase personnel to more than 3,000 officers and 45,000 enlisted men and women. In the wake of that law, Wichita-based BAC, the Stearman Division of Boeing and Cessna Aircraft Company began receiving contracts for large numbers of airplanes. Roosevelt’s appropriation, however, was only the beginning of a massive procurement initiative aimed at preparing America for the war that would soon strike its shores.
In anticipation of a surge in demand for training airplanes, Beech Aircraft executives stretched the company’s financial power to the limit, securing loans from the Federal Government’s Reconstruction Finance Company to expedite construction of production facilities. Ted Wells and his engineering department soon turned their attention to design versions of the Model C18S suitable for training thousands of fledgling pilots, navigators and bombardiers.
In 1939, nearly two years before America’s entry into the war, BAC delivered a military Model 18D to the Philippine Army Air Corps, and the Swedish Royal Air Force took delivery of a Model 18R modified into an aerial ambulance. One year later, the Republic of China bought six Model AT18R featuring internal bomb racks, provisions for fixed and flexible machine guns as well as a bombardier station in the nose section.
In what must have seemed like a prophetic fulfillment to Walter and Olive Ann, late in 1939 and continuing into 1940, BAC received orders from the U.S. Army Air Corps and the U.S. Navy for special versions of the Model 18S. Among these were 14 ships designated by the Air Corps as F-2 and F-2B. Designed specifically for high altitude aerial reconnaissance training, the cabin was configured to accept a variety of camera installations including equipment for night photography. The F-2 series were powered by Pratt & Whitney R-985-14 radial engines each rated at 450 hp, and regularly flew at altitudes up to 25,000 feet. The Air Corps eventually took delivery of 56 F-2 aircraft.
The Navy ordered five Model 18S converted to accept a special cupola built above the cockpit that housed an observer/operator to control aerial target drones. Designated JRB-1, all five of the monoplanes were delivered in 1940 and were equipped with R-985-AN-4 of -50 radial engines. Another order from the Army Air Corps that year called for 11 Model 18S configured as light duty transports and designated C/UC-45. The Wichita factory built more than 1,400 UC-45 airplanes during the war, with many sent to serve with the Royal Air Force in Great Britain, designated “Expeditor I” and “Expeditor II.”
Other important derivatives based on the wartime Model C18S included:
• C/UC-45F: Built later in the war, the C-45F was intended as a VIP and general transport that could carry up to five passengers and 80 pounds of baggage.
• SNB-1: The Navy needed a small transport capable of training bombardiers and operators of machine gun turrets, which were standard fitment on medium and heavy bombers in naval service. These airplanes were almost identical to the Army Air Corps’ AT-11 with a maximum gross weight of 9,300 pounds. In 1942 only 14 airplanes were built, but by war’s end the Navy had 320 SNB-1s in inventory.
• SNB-2: Production of the SNB-2 for the U.S. Navy began in July 1942. It was designed as a navigation trainer but could serve as a general purpose transport. Powered by R-985-25 radial engines, the SNB-2 had a maximum speed of 225 mph and a maximum gross weight of 8,700 pounds. The Navy took delivery of 606 SNB-2 during the war.
• AT-7: As with the Navy and its SNB-2, the U.S. Army Air Forces (AAF) needed a small, twin-engine transport equipped to teach navigation by the sun and stars. The cabin was equipped with drift meters, work tables and various compasses. In addition, an auxiliary instrument panel displaying essential flight information such as airspeed and altitude was installed in the front of the cabin for student reference in solving navigation problems. Celestial sightings at night were made through a small, clear Plexiglas dome in the upper fuselage. The AT-7 trained thousands of navigators who later guided hordes of American bombers to their targets over Germany and Japan. The Army took delivery of 884 AT-7 during the war.4
• AT-11: The AT-7 trained navigators, but the Army’s AT-11 trained men to drop bombs on the enemy. The airplane was equipped with a large Plexiglas nose section for the student bombardier and housed the top-secret Norden bombsight that made accurate bombing possible. Based primarily in the Southwestern United States because of the region’s favorable flying weather year round, the AT-11 normally flew with two pilots and three students. The fuselage featured internal bomb racks that held 10, 100-pound practice bombs. As with navigators, bombardiers were desperately needed for the massive bombing campaigns over occupied Europe, the Pacific and Japan. As a result, more than 1,500 AT-11s were built.
• Other minor variations of the C18S produced only in small numbers were the AT-7A, equipped with floats and skis; AT-7B, specially equipped for service in cold weather climates in sub-zero temperatures; and the AT-7C was equipped with more sophisticated avionics and autopilot than the standard airplanes. The AT-11A was an AT-11 configured for aerial photography as well as bombardier training. The type was also designated T-11-BH.
By war’s end, more than 14,000 Beechcrafters had manufactured more than 7,000 military aircraft for U.S. and allied fighting forces. The majority were versions of Model C18S, but a few hundred “Staggerwing” cabin biplanes were built as military variants of the commercial Model D17S. Late in 1944 it became obvious that a devastated Germany and a fanatical Japan were facing certain defeat at the hands of the Allied nations. Walter Beech was anxious to return to peacetime production, and he soon had Ted Wells working on a postwar replacement for the trusty Model C18S.
That replacement was the Model D18S that featured a maximum gross weight 20 percent higher than that of its predecessor. Other major upgrades included a redesigned main landing gear, stronger wing center section, lengthened engine nacelles and a new instrument panel. When introduced in the summer of 1945, the D18S had the distinction of being the first postwar commercial, nine-place, multi-engine airplane to receive an Approved Type Certificate. The latest Beechcraft sold well. Production quickly reached two per day as pent-up demand for new aircraft made customers quick to plunk down cash to secure a position on the production line.
The factory produced 296 D18S aircraft in 1946 – the highest number for any Model 18 in a single year. When production ended in 1955, more than 1,000 had been delivered to customers. Powered by R-985 radial engines, maximum speed of the D18S was 230 mph at 5,000 feet. The next-generation Beechcraft cost $61,500 for a standard-equipped airplane.
In 1954, the D18S gave way on the production line to the Model Super E18S that introduced major changes to the airframe. These included cabin height that was increased six inches; four cabin windows on each side of the fuselage; a larger, air stair-type entry/exit door and a maximum gross weight of 9,300 pounds. Wingspan was increased 48 inches to 49 feet eight inches, resulting in a total wing area of 361 square feet. The E18S proved to be popular with longtime Model 18 operators, and 451 were built before production ended in 1960.
Demand for an improved Model 18 led to development of the Super G18S introduced for the 1960 model year. The most salient change was installation of a new, larger windshield that improved visibility and the dispersion of rain. In addition, a large center cabin window afforded passengers
a better view of the sky and the earth below. Pratt & Whitney R-985 engines turning three-blade Hartzell constant-speed propellers was a feature of the G18S. A total of 154 airplanes were built from 1959-1963 when the final version of the venerable Model 18 took to the air.
The year 1962 marked the 25th year of consecutive production of the legendary Beechcraft Model 18. In August, Beech Aircraft Corporation unveiled the Super H18 featuring a maximum gross weight of 9,900 pounds, a useful load of more than 4,200 pounds (the highest for any version of the Model 18), and a speed of 236 mph. Other key changes centered on the main landing gear struts that featured a forged, heat treated half-fork assembly instead of the full-fork design, and the adoption of smaller 8.50 x 10 wheels and tires. The H18S also featured electrically-operated cowl flaps and for the first time in any Model 18, air conditioning was available.
In 1963, the H18S was available with a choice of landing gear configurations, either standard, conventional-gear or a tricycle design developed by Volpar. The latter eventually became standard chiefly because a majority of customers preferred a tricycle gear. In November 1969, Japan Air Lines took delivery of the last three production Super H18s that were employed as multi-engine trainers. The limited number of H18s built (149) was a sign of the times. The introduction of lightweight, powerful and reliable turboprop engines such as the revolutionary PT6 series developed by Pratt & Whitney Canada hastened the demise of static, air-cooled radial engines (and to a lesser extent, some opposed piston engines). More importantly, Olive Ann Beech had decreed that two PT6 en-gines be mated to a Queen Air airframe for flight testing. Her decision ultimately paved the way for introduction of the Model 90 King Air.
Ted Wells’ classic Beechcraft Model 18 was more than an iconic executive transport. It served with distinction in World War II and the Korean and Vietnam conflicts, and under the care of private owners and museums, will continue to roar through the skies for years to come.
Notes:
1. As of 2015, the R-985 is still in plentiful supply and powers not only versions of the venerable Beechcraft Model 18, but a variety of other antique and classic aircraft.
2. Parmerter, Robert K.: “Beech 18—A Civil and Military History;” The Staggerwing Museum Foundation, Inc., Twin Beech Society, a division of the Staggerwing Museum Foundation, Inc.; 2004.
3. Parmerter, Robert K: “Beech 18—A Civil and Military History;” The Staggerwing Museum Foundation, Inc., Twin Beech Society, a division of the Staggerwing Museum Foundation, Inc.; 2004. The Model 18S was available with Jacobs or Wright Aeronautical radial engines, but an only limited number of airframes were built with these powerplants.
4. According to “The Official Guide to the Army Air Forces,” the Army Air Forces was created on June 20, 1941, to coordinate the activities of the Air Force Combat
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