Cessna Skymaster, Model 336

I was always fascinated with the Skymaster when I was younger, and I remember we had one at the Air-Park. I thought it was the coolest thing to see both propellers spinning. This airplane has a special place in my heart, and I know that I’ve covered this before in a previous post, but I found this article so interesting that I had to share it with you.

I was reading this fascinating article from Flying magazine about the Cessna Skymaster 336, and you’d love this. It’s a unique plane that first came out in 1963 and revolutionized how multiengine aircraft were designed, thanks to something called a “push-pull” or centerline thrust configuration. Basically, it has two engines: one mounted on the front of the fuselage like most airplanes, and another mounted on the rear. This setup solves one of the trickiest issues with multiengine aircraft – handling when one engine fails. In the Skymaster, there’s no significant yaw or control issues when flying on just one engine. It’s as simple to fly on one as it is on two!

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Aircraft Specs and Performance

This thing is powered by two Continental IO-360-A engines, each delivering 210 horsepower with constant-speed McCauley propellers. It cruises at around 173 mph at 7,000 feet and hits a top speed of 183 mph at lower altitudes. The service ceiling with both engines is 19,000 feet, but even on just the rear engine, it can climb to 9,500 feet! Its maximum range is about 1,240 miles, so it’s a solid performer for a light twin.

Short takeoffs and landings are another standout feature. The Skymaster needs just 625 feet to take off and can land in 655 feet. It’s described as having one of the shortest ground runs of all the light twin-engine planes at the time.

Cabin and Comfort

The cabin is spacious and well thought out, with seating for four to six people and great visibility thanks to over 1,700 square inches of windshield. Cessna did a great job soundproofing it too – they used fiberglass insulation and heavy carpeting, which makes for a quieter and more comfortable ride.

Flight Experience and Simplicity

What’s really cool is that the Skymaster is beginner-friendly for single-engine pilots looking to step up to multiengine planes. With just five to ten hours of training, most pilots can handle it. The FAA even created a special pilot rating specifically for this aircraft: “Aircraft Multiengine Land (or Sea)-Limited to Center Thrust.”

Flying it is simple because of its conventional controls. The front and rear engines are isolated by firewalls, and all key flight instruments are logically arranged in the cockpit, making it very user-friendly for pilots.

Testing and Innovations

Cessna really put this aircraft through its paces during development, starting way back in 1957 with the concept. By the time it hit production in 1962, it was one of the most thoroughly tested aircraft Cessna had ever built. One feature they tested heavily was the plane’s ability to handle emergency situations, like flying on a single engine from a standstill, which it handles remarkably well.

Notable Options

You could kit it out with optional features like de-icing systems, an oxygen system for higher altitudes, and various radio and autopilot packages. There were even 10 different color combinations to choose from!

Bottom Line

This Skymaster was a game-changer for pilots who needed the safety and reliability of a multiengine aircraft but wanted the simplicity of a single-engine design. It was designed with both professionals and private pilots in mind, making it one of the most versatile planes in its class back in the 60s.

The price back in 1963 was around $39,950 – quite steep for the time but justified by its advanced features and capabilities. The article describes the plane as a well-rounded performer that addressed a lot of the safety and handling concerns pilots had with traditional twins.

Isn’t that such an interesting evolution in aviation? I could totally see why this plane grabbed so much attention when it was first released!

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Cessna Skymaster Details

Source: Excerpts from “Cessna Skymaster” – FLYING Magazine, May 1963

Main Theme: Introducing the revolutionary Cessna Skymaster (Model 336), a light-light tandem-twin aircraft distinguished by its unique centerline thrust configuration. The article emphasizes the Skymaster’s safety, simplicity, and performance, particularly its single-engine handling capabilities.

Most Important Ideas & Facts:

I. Centerline Thrust:

• Defining Feature: The Skymaster’s defining feature is its push-pull powerplant configuration with engines mounted fore and aft on the fuselage centerline.
• Safety & Handling: This configuration provides multiengine safety while offering the handling simplicity of a single-engine aircraft.
• Single-Engine Performance: The Skymaster is capable of single-engine takeoff and exhibits no directional control problems during single-engine operation.
• “That is as easy to handle on one engine as on two (there are no engine-out directional control problems);” “That is capable of single-engine takeoff from a “standing start” (the airplane flies well on less than half of its total 420 horsepower);”
• New FAA Rating: Pilots checking out in the Skymaster will receive a new FAA rating: “Aircraft Multiengine Land (or Sea)-Limited to Center Thrust.”

II. Design & Performance:

• Classic Cessna Features: Retains the classic Cessna high wing with external bracing and one-piece spring-leaf fixed landing gear.
• Powerplants: Two Continental IO-360-A engines (210 hp each) with fuel injection and constant-speed, full-feathering McCauley propellers.
• Performance Highlights:Top Speed: 183 mph at 2,000 feet
• Cruise Speed: 173 mph at 75% power at 7,000 feet
• Optimum Range: 1,240 miles at 10,000 feet with 128 gallons of fuel
• Service Ceiling: 19,000 feet (twin-engine); 9,500 feet (single-engine, rear powerplant only)
• Short Field Capability:Takeoff ground run: 625 feet
• Landing roll: 655 feet
• “it has the shortest takeoff-ground-run and landing-roll of all the light twins currently certificated.”

III. Cabin Features:

• Spacious & Comfortable: Roomy cabin with 138 cubic feet of total volume, comfortable seating, and excellent visibility.
• Soundproofing: Extensive soundproofing with mastic sound deadener, fiberglass insulation, and heavy carpeting.
• “The Skymaster cabin is extensively soundproofed.”
• Layout: Flight instruments on the left panel, radios in the center, engine instruments and system indicators on the right.
• Fuel System: 92.8-gallon fuel capacity with main tanks in the outboard wing panels and auxiliary tanks in the inboard panels.

IV. Single-Engine Operational Characteristics:

• Minimal Yaw: No significant yaw experienced during single-engine operation.
• “There is no directional control problem during single-engine operation…”
• Performance with Forward Engine Feathered: Slightly better climb performance and higher single-engine service ceiling due to reduced drag and aerodynamic benefits.
• Important Speeds: 90 mph for best single-engine rate of climb and 80 mph for best climb angle.
• Thrust Indicator Lights: Red warning lights indicate an engine that is not developing sufficient power.

V. Other Notable Features:

• Electrical System: 28-volt DC system with two alternators and a battery.
• Lighting: Landing and taxi lights, plus two rotating beacons.
• Emergency Exit: Left main window serves as an emergency exit in five- and six-seat configurations.
• Optional Equipment: De-icing system, oxygen system, autopilot, various radios and avionics.

VI. Development & Testing:

• Extensive Testing: The article emphasizes that the Skymaster was rigorously tested during its development, with the prototype accumulating significant flight hours.
• “Cessna has experienced little or no trouble with the new engines during its development program. They emphasize that Model 336 is the most thoroughly tested of any aircraft they have built.”
• Timeline: Key dates in the Skymaster’s development are provided, from the start of preliminary studies in December 1957 to the first production aircraft in November 1962.

Cessna Skymaster Timeline

December 1957: Cessna begins preliminary studies on the concept of centerline thrust for aircraft.

January 1960: Cessna approves the Skymaster configuration, utilizing the centerline thrust principle.

April 1960: Construction begins on the first engineering prototype of the Skymaster.

July 1960: A full-scale mockup of the Skymaster is completed.

February 28, 1961: The first engineering prototype of the Skymaster successfully completes its maiden flight.

March 14, 1962: The second engineering prototype of the Skymaster takes its first flight.

May 22, 1962: The Federal Aviation Administration (FAA) grants type certification to the Cessna Skymaster.

August 1962: The pre-production prototype of the Skymaster is flown.

November 1962: The first production model of the Skymaster is rolled out.

May 1963: The first Skymaster demonstrators are delivered to Cessna dealers.

Robert I. Stanfield: Author of the “Pilot Report: Cessna Skymaster” article in the May 1963 issue of FLYING magazine. He piloted the third production Skymaster (N1703Z) and details his experience with the aircraft’s performance and handling.

William “Bill” Thompson: Chief of Cessna’s Flight Test and Aerodynamics Branch. He accompanied Stanfield during the test flight of the Skymaster, specifically for the single-engine takeoff and go-around demonstration.

Cessna Aircraft Company: The manufacturer of the Skymaster. The company is highlighted for its extensive testing of the aircraft and its commitment to producing safe and reliable aircraft.

Continental Motors Corporation: Supplier of the two IO-360-A engines used in the Skymaster. Each engine is a six-cylinder, horizontally opposed, fuel-injected engine rated at 210 horsepower.

McCauley Propeller Systems: Manufacturer of the constant-speed, full-feathering propellers for the Skymaster. Each propeller measures 76 inches in diameter.

Federal Aviation Administration (FAA): The governing body that certified the Skymaster and created the new pilot rating “Aircraft Multiengine Land (or Sea)-Limited to Center Thrust.”

Goodrich Corporation: Provider of the optional lightweight wing de-icing system for the Skymaster.

Aircraft Radio Corporation, King Radio, Narco, and Sunair: Companies that produced avionics and radio equipment available as optional installations for the Skymaster.

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Pretty cool, right? Thanks for joining me on a journey, and I’ll see you in the next one!