Copyright 2000, 2001 by Richard Harris
All Rights Reserved

Revised September 2001

In the late 1940's / early 1950's, aeronautical engineer Ted Smith designed the first Aero Commander twin, the Model 520 -- which would become the forerunner of a long line of respected medium-sized, twin-engine private aircraft. The first prototype flew on April 27, 1948, and the first production Model 520 came out of the Bethany, Oklahoma factory in August of 1951. Using using modern, slim, "flat-six" piston engines, and modern, lightweight, sheet-metal hollow-shell ("semi-monocoque") construction, Smith's Model 520 was the first true, modern "light twin" on the market.

The 520 bore more than a passing resemblance to the Douglas A-26 Invader -- a World-War-II attack bomber (shown at left) which Ted Smith had helped design. With its high wings (45 feet long), and a 7-foot-tall tail, the spacious Aero Commander 520 (1952 model shown at top, right) was a remarkably grand airplane for a "light twin." It had lots of interior room, and considerable load capacity, easily seating 5, and able to squeeze in two more in optional rear-facing seats squeezed between the front and back seats. Powered by a pair of 240-horsepower, geared "flat-six" piston engines, the 520 could cruise along at about 200 miles per hour -- in a day when many airliners were still only flying at 180 miles per hour.

In the early 1950's, World-War-II vintage, war-surplus military transports and light bombers had flooded the civilian market, being converted to carry passengers or serve as executive transports. They were generally either fast or capable of great loads, or both. But most were tugged along by antiquated, massive, roaring, fuel-hungry, oil-burning radial engines (shown at right). In general, the war-surplus, twin-engine planes, themselves, were heavy, gas-guzzling, noisy, war-worn beasts, and not well-suited to efficient-and-comfortable flying for personal or business use. Both inelegant and impractical, they lacked the finesse of a truly personal plane.

The only currently-manufactured civilian twin competing with the Aero Commander Model 520 was the the 15-year-old Beechcraft Model 18 "Twin Beech" which -- though powerful, fast and roomier than the Model 520 -- was still powered by noisy, thirsty, 1930's-vintage radial engines, and was supported on awkward, obsolete, "tail-dragging" landing gear (two main wheels and a tailwheel). These features, added to its great bulk and crude aerodynamics, meant that the Twin Beech was not nearly as graceful, efficent, gentle, or well-mannered craft as the Aero Commander Model 520.

And so the first Aero Commander was -- at first -- in a class by itself.

It was soon joined in the market by the Beechcraft Model 50 Twin Bonanza (only loosely related to the popular Beech Bonanza) -- a low-winged modern medium twin with performance and cabin space comparable to the Model 520. But the Aero Commander, with a slight edge in efficiency and capacity, and better flying characteristics, remained the better buy. Hundreds were sold over the next few years.

Despite the grand aura of a private airliner, the Model 520 was blessed with superb handling characteristics, great visibility, an easy-to-manage cockpit, and good short-field / rough-field capability (important in an age when most airfields were still crude, unpaved landing strips). To demonstrate its great resistance to engine-out handling problems (which plagued light twins of the day), a propellor was removed from the "critical" engine of the first prototype -- which was then flown, non-stop, from Oklahoma to Washington, D.C. This successful stunt would serve as a valuable lesson for a company that would eventually benefit considerably from "stunt marketing," thanks to an extraordinary aviatrix, Jerrie Cobb and a high-flying company vice-president named Bob Hoover (see below).

To manufacture his design, Smith had created a company called Aero Design and Engineering, in Bethany, Oklahoma -- a suburb of Oklahoma City. The company quickly became known as Aero Commander, a name commonly applied to its line of twin-engine light airplanes. By 1965, it would become the Aero Commander Division of the much larger Rockwell-Standard Corp..

Though Ted Smith, like most great airplane designers, was soon separated from the company he'd created, his creative genius was not wasted. Though, at first, Aero Commander produced light twin-engine airplanes exclusively, the original Aero Commander design spawned a generation of great airplanes (some of which Ted Smith helped design), and the company soon expanded into a wide range of aircraft, from light singles and cropdusters to full-sized business jets.

Meanwhile, Smith, himself would continue his creative genius. Above, right, he's shown surrounded by models of the various aircraft he helped create, and behind him is the prototype of his next accomplishment -- another great "pilot's airplane" which he created in the 1970's:   the sleek, fast Aerostar. The world's fastest piston-engined personal aircraft, the Aerostar (also shown at left) is capable of speeds of over 300 miles per hour, and a pressurized version can climb to jet altitudes. Though the Aerostar was bounced from company to company, (first being dropped by Aero Commander, and picked back up by Ted Smith, himself -- then bought up by Mooney and later by Piper), Ted Smith's Aerostar design would endure. For a quarter of a century -- living beyond Smith, himself (who died in 1976) -- the Aerostar has reigned as the ultimate piston-engined speed-machine for the fast-flying owner/pilot.

In the meantime, though, Smith's original Aero Commander design would also prosper, in a variety of incarnations -- some of which Smith himself would help design.

In 1954, Aero Commander's 500 series expanded from the original Model 520 to include the more-powerful 560 and 580 (early Aero Commander model names roughly matched their horsepower) -- and the less-powerful / more-efficent 500 (a 1958 Model 500 is shown at right). All of them looked about the same -- and generally were, except for the engines. Several were bought by the U.S. Air Force and U.S. Army for military liaison/utility use (designated L-26, U-4 and U-9), particularly as a short-haul transport and reconnaisance plane operating from "unimproved" grass strips in forward areas. One was even used as President Eisenhower's personal transport (Click here for more details, on another website.).

Even more Aero Commanders were bought by civilian operators, excited at the prospect of owning a personal plane with the headroom and grandeur of a private airliner. (The idea of owning a plane chosen for the President of the United States didn't hurt sales, either.) The Aero Commanders' long wings and tailbooms -- and hefty bulk -- gave them a remarkably smooth ride in turbulent air, compared to other private planes of the time. Thrumming along at speeds up to 225 miles per hour, and blessed with good short-field / rough-field performance, the Aero Commander twins provided the owner with quick access to big airports and remote places alike.

A streamlined version of the 500 became the Shrike Commander, which soon became famous for its spectacular appearances at airshows, with former fighter pilot (and later Vice President of Rockwell) Bob Hoover at the controls. After flying an airshow routine in his World-War-II vintage North American P-51 Mustang fighter, Hoover would get into his big, twin-engined Shrike Commander and perform the same stunts -- with both engines running, then again with one engine runing, and finally the whole routine with no engines running -- eventually gliding to a landing, and coasting smoothly to the same spot on the airport from which he'd departed.

Taking advantage of the Shrike's smooth ride and easy controllability, Hoover would take journalists and photographers aloft and demonstrate his most famous stunt:   pouring tea into a glass balanced on the throttle quadrant -- while performing a complete, perfect vertical loop, allowing the centrifugal force of the loop maneuver to keep the tea flowing towards the glass, even when upside-down. Though earning himself a reputation as "the pilot's pilot," Hoover also brought fame, credibility and sex-appeal to the Aero Commander line. The Shrike's many virtues, and the spectacular Hoover exhibitions, soon made the Shrike Commander one of the most lusted-after planes in the world, and brought it the reputation as -- among business twins -- the ultimate "pilot's airplane."

Despite its appeal as a pilot's airplane, most pilots couldn't afford the big plane, and by the early 1960's the Aero Commander twin was being beaten in the market by cheaper, lighter, sleeker, more-efficient and speedier light twins from Cessna, Beech and Piper. The big Commander twins were not nearly as efficient and speedy as these newer twins in the same class with it (with comparable price, horsepower and seating capacity). To get you anywhere, Aero Commanders simply guzzled more gas than other popular twins, and generally didn't get you there as fast. Add in the expensive maintenance on the big, geared engines, and it was hard for an Aero Commander to make sense to the person footing the bill.

1. Beech Aircraft's hefty Model 50 Twin Bonanza -- a towering beast with performance, capabilites and costs comparable to Aero Commander's 520 -- had given way to Beech's smaller, more efficient, 4-seat D95A Travel Air -- derived directly from Beech's popular single-engine Bonanza. The Travel Air would, in turn, soon become the fast, popular 4-seat Beech Baron light twin (a 6-seat version is still in production today, shown at left).
2. Meanwhile, on the high end, the Twin Bonanza had evolved into Beech's elegant Queen Air with a grand, airliner-style cabin seating 6 to 9 people. Entering the plane by its "airstair" door, was reminiscent of boarding an airliner of the times. After entering, passengers walked to their seats, through a generous aisle, almost standing upright. A partition separated the cockpit from the cabin. Carrying the airliner style a bit further, the Queen Air offered optional air-conditioning and even included a private lavatory for long trips. With these developments, Aero Commander lost its dominance in the "top of the line" of business aircraft.
3. Piper Aircraft had introduced its cheap, efficient 5-seat Apache -- the first truly popular light twin. Homely, but cheap and durable, the Apache would become one of the biggest-selling twins of all time. By 1960, it would be stretched into the stout, swift 6-seat Aztec. In 1963, Piper would also introduce the sleek, efficient Twin Comanche (derived from Piper's popular 4-seat, single-engine Comanche speedster), shown at right.
4. Cessna Aircraft had already introduced its speedy, efficient Model 310, which could speed past most Aero Commanders, carrying 4 people, while using far less fuel.
   

Each of these manufacturer's smaller twins would soon be stretched to accomodate 6 people, largely neutralizing the value of the Aero Commander's popular 7-seat capacity (which -- in reality -- was seldom fully useable, if full fuel tanks or husky passengers were to be carried).

To improve efficiency and speed, Aero Commander streamlined engine nacelles (which helped), and added the pointed Shrike nose to other models (which made little difference, except to appearances and making room for an optional weather radar). But making the Aero Commander twins lighter and slimmer wasn't really practical:   Aero Commanders had been designed around the big-twin idea, and could only get bigger -- not smaller and more efficient.

If Aero Commander couldn't make the 500 series smaller, at least they could make it bigger. So The 500 series was expanded to produce the 600 series, hauling between 7 and 10 people (counting the cockpit seats). First came the Model 680 Super, which was actually just a strengthened Model 500, with much-more-powerful, geared-and-turbocharged, 350-hp engines. Various refined versions followed, including the 680E, whose longer "extended" wing allowed a greater load, while providing higher aerodynamic efficiency. Next was the "680F" whose flatter engine nacelles reduced drag substantially, though the wheels had to rotate sideways during retraction, to fit into the slimmer space. (The 680F owned by NASA is shown at right, "tufted" with tiny pieces of yarn to analyze the airflow around the plane).

From the 680F model, the Aero Commander line briefly split into two different cabin-comfort directions:   pressurization and lengthening.

First, to permit passengers to ride in the comfortable, clear (but thin) air high above stormy weather, Aero Commander developed a pressurized version of the 680F -- the 680FP, which in 1958 became the 720 Alti-Cruiser, the world's first government-approved, pressurized, non-airline business plane. Pressurizing the cabin overcame the problem of the too-thin-to-breathe air of high altitudes. Rising above the turbulent air below, Aero Commander passengers and crew enjoyed a gentler, safer ride, while overcoming the barriers to flight created by many high-rising dangerous storms. But the idea was a bit ahead of its time, and only a few were sold. By 1960, though continuing the idea with the lower-powered 680FP, Aero Commander had dropped the Alti-Cruiser for a different approach to luxury.

An un-pressurized version of the 680F was lengthened into the 680FL, making room for up to 9 people in all (shown here, recently modified with "winglet" wingtips).

Interestingly, lengthening the 680F airframe into the 680FL, despite the addition of weight, reportedly did nothing to increase the airplane's drag. An aerodynamic analysis revealed that extra drag created by the extra surface area was offset by the more-aerodynamic hull shape created by stretching the airplane a bit.

With an aisle between the seats, it was like a mini-airliner. (In fact, several of the 680FL's and their successors were actually used as short-haul airliners). This class of plane came to be known as "airliner-cabin class," or simply "cabin-class." The Beech Model 18 had first claim to the class, and by 1960 Beech had debuted its elegant Queen Air. The Aero Commander 680FL was introduced the very next year. Cessna and Piper would soon follow with their cabin-class mini-airliners (the Cessna 400 series and the Piper Navajo). In 1965, the 680FL was appropriately renamed the Grand Commander.

Finally, in late 1965, the stretched (680FL) and pressurized (680FP) versions were reunited in the 680FLP Pressurized Grand Commander, which later became known as the Courser Commander. The last production version would be the 685 (shown here), -- actually a Model 690 Turbo Commander (see below), with piston engines in place of the usual engines, and with drag-reducing up-swept "winglets" on its wingtips. By the end of 1979, when production of piston-engined, stretched Commanders ended, 66 copies of the Model 685 had been built, along with dozens of the various 680FL and 680FLP models.

By the mid-1960's, Aero Commander twins -- colloquially known as "Twin Commanders" -- had become quite popular as executive transports, but still suffered from sluggish speed in the 500 series, and so-so speed in the 600-series.

Also, the big 600-series were powered by notoriously-troublesome geared engines -- the only efficient engines big enough for the job. By taking ordinary airplane engines, then "turbocharging" them (forcing more air/fuel mixture into the engines with compressor fans, spun by exhaust-driven turbines), and then gearing the engines to turn at higher speeds than they were originally designed for, the engine-company's engineers were able to squeeze more power from the piston engines -- but at a severe cost in durability and reliability.

The problem came to a head in the mid-1960's, when Beech Aircraft began introducing powerful, compact "jet-prop" turbine engines (Pratt & Whitney PT-6A turboprops, to be exact) to executive planes -- with their wildly successful, high-flying Beech King Air (shown at right). These "turboprops" were jet engines driving propellors, for an ideal compromise between the low-speed, low-altitude effiency of propellor-driven engines, and the high-speed, high-altitude capabilities of the jet engine.

The Beech King Air swept the market like a storm, as executives and tycoons and foreign potentates (and even military generals) began lusting after this grand "personal airliner" that could soar high above the clouds (higher than any pressurized Commander), and blast along at "airliner" speeds (though the bulky King Air was really only slightly faster than the Aero Commanders). The King Air quickly began siphoning sales away from all other top-of-the-line business twins, including Aero Commander's best. It was definitely catch-up time for Aero Commander.

It took Aero Commander until 1967 to respond, by putting powerful, new Garrett AirResearch TPE-331 turboprops on its 680FLP. The result was the Aero Commander 681 (commonly known as the Turbo Commander, or -- briefly -- Hawk Commander). It soon evolved into the slightly more powerful, and more-refined 690. (A 1986 Model 690B II is shown at left.) This roomy, fast, high-flyer helped Aero Commander regain much of its status in the business aircraft market.

Faster, by far, than Beech's King Air, let alone any of the large Cessna or Piper piston-engined twins, the well-mannered Turbo Commander was blessed with a cockpit that afforded great visibility for pilots, and remarkably simple cockpit systems, while exuding the sophisticated image of an airliner's flight deck.

The low-slung 690 nevertheless lacked the awe-inspiring "ramp presence" of the King Air's towering high stance, and -- worse -- had engines (Garrett AiResearch TPE-331's) with greater operating costs than that Beech's King Air (powered by Pratt & Whitney PT-6A's). A final disadvantage was the placement of the Turbo Commander's engines and propellors. While Beech's engines and propellors were well forward of the passenger compartment, the high-wing design of the Turbo Commander necessitated putting engines and propellors -- along with all their noise -- right next to the passenger compartment.

Still, with a roomy cabin and the advantage of a spectacular earthward view for passengers through huge picture windows (the King Air's low wing prevented much of a view from its small, round porthole windows), the Turbo Commander retained a great appeal. And no one could deny their speed. Until the Japanese Mitsubishi MU-2 turboprop came on the scene, no prop-driven business twin afforded greater speed -- let alone more scenic views -- than the Turbo Commander.

Throughout the 1970's and early 1980's, the 690/695/840/900/980/1000 series of turboprop twins followed, each expanding the performance and capacity of the plane before it, but all of them retaining the distinctive basic Aero Commander design:   high-wing twins, with long graceful wings and tall tails, roomy, rectangular cabins (versus the cramped, round cabins of competing planes), magnificent flying characteristics and hefty load capacities.

A 1980-model 840 is shown here, incorporating tiny up-swept "winglets" at the wingtips, to reduce drag caused by wingtip vortices at cruise speed. By the time the Aero Commander's Model 900 came on the scene, more efficient and reliable versions of the Garrett engine (particularly the TPE-331-10, colloquially known simply as "Dash 10") were available, increasing the reliability, affordability and value of the Turbo Commander. Many older models have since been modified -- re-engined -- with the "Dash 10 mod."