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December 2013 Mystery Plane – The Sundorph A-1 “Special”


The December Mystery Airplane drew a good number of responses; the first received was from Dan Cullman who correctly identified the aircraft as the Sundorph Special. Others who submitted correct answers were Roy Oberg, Wayne Muxlow, David Helmso and Bradford Payne.

For further information read Wesley Smith’s article that follows.

The Sundorph A-1 “Special”
by Wes Smith

Entered in the 1937 Bendix Trophy Race, the Sundorph Special was piloted by Eiler Sundorph and John Yost. Following the race the aircraft was disassembled.

Entered in the 1937 Bendix Trophy Race, the Sundorph Special was piloted by Eiler Sundorph and John Yost. Following the race the aircraft was disassembled.

In the years leading up to the Second World War, a series of air races were held involving the shortest time (and hence, highest speed) over a fixed distance. The first such race was the 1928 New York to Los Angeles Derby, held in 1928. Additonal races were held in 1929 and 1930, and were known as the Los Angeles to Chicago Derby. The next race, held in 1931, became the first Bendix Trophy Race, and was flown between Los Angeles and Cleveland. Collectively, all such races were known as the National Air Races. The seventh Bendix Trophy Race, held in 1937, covered a distance of 2,042 mi. This was combined with an air show at Cleveland which was held over Labor Day weekend. There were two racing events in 1937. In addition to the Bendix Trophy Race, there was also the Thompson Trophy Race, which was a 200 mi. speed event, held over a course of four pylons. The Thompson, unlike the Bendix, was designed to test low altitude speed and maneuverability. It was a closed-course event, with each leg being 10 miles in length, around four pylons 50 ft. high.

On 1 June 1935, the prototype Cessna C-34 Airmaster, was test-flown at Wichita. It was powered by a 145 hp Warner Scarab, and attained a Vmax. of 162 mph, with a Vc of 143 mph. The wings were of conventional fabric-covered wood, and the fuselage was composed of steel tubing, covered with fabric. Like the wing, the tail of the C-34 was of cantilever construction, resulting in a low-drag airframe. The initial climb rate was 1,000 fpm, with a max. ceiling of about 18,900 ft. George Hart, a friend of Clyde Cessna’s, made the initial test flight, ATC 573 being granted in 1935. The wood and fabric flaps were replaced by aluminum frame components on production aircraft. The second airframe was personally delivered by Dwane Wallace (Cessna’s nephew) and George Hart, to its owner, Ross E. Colley of Tuxpan, Mexico (X 14425, s/n 255; reregistered as XB-AJO). Flying from Wichita to Tuxpan, the aircraft consumed only $15.24 of fuel, averaging 16,9 mpg.

The third C-34, completed on 10 Sept. 1935, was entered in the National Air Races, piloted by George Hart. Painted yellow with blue trim, the aircraft won the Detroit News Trophy Race (a four-event race for; economy, speed, and minimum take-off and landing capabilities with the best passenger safety and comfort). Hart went on to pilot the same aircraft in the Detroit News 550 cubic inch Sweepstake Race, winning the Silver Loving Cup. Cessna, then sold his interest in the company, placing his nephews, Dwane and Dwight Wallace, officially retiring on 8 October 1936. However, the C-34 was just getting warmed-up.

In 1936, Dwane Wallace again entered a C-34 in the Detroit News races, and the All American Race held at Miami, Florida. Piloting the green Cessna (NC 15852 s/n 320) to victory, Being the third event in the series, the cup was now the permanent possession of Cessna. Billed as the; “world’s Most Efficient Airplane,” the C-34 went on to win the Argentine Trophy Race with a speed of 156.13 mph. Sidney L. Turner, of the Surrey Flying Service also entered C-34 G-AEAI (s/n 314) in the 1936 Croydon Air Derby, winning the Wakefield Trophy Race in 1936. The aircraft was impressed into RAF service during the Second World War (s/n/ HM 502). It was destroyed by fire after the war at Squires Gate in 1950, but was replaced by another C-34, G-AFBY (s/n 319), which was wrecked in 1951. Of 32 C-34s built in 1936, only these two were exported to the United Kingdom. Another, went to East London, South Africa, and a total of 42 C-34s were built.

The Cessna C-37 of 1937 with a Warner 145 engine was owned by actor Robert Cummings. He also owned a Porterfield and a Molt Taylor designed Aerocar.

The Cessna C-37 of 1937 with a Warner 145 engine was owned by actor Robert Cummings. He also owned a Porterfield and a Molt Taylor designed Aerocar.

At the end of 1936, C-34 (s/n 330; X 17070) was converted to the prototype C-37. The improved model sported electrically-operated flaps, a refined cowling, an improved shock-absorbing system, and a cabin widened by 5 in. The engine remained unchanged, and the aircraft handled about the same as the C-34. Still, the criticisms of the plane remained. The cabin roof was too short, and forward visibility was restricted. During the New York City National Aviation Show, held the week of 10 February 1937, Dwane Wallace sold a total of 5 C-37s, at a price of $5,4090.00 ea. By year’s end, a total of 47 had been sold. The designation; “C-37,” was not officially adopted until the following year, when the C-38 was introduced. One C-37 was fitted with Edo floats, and was flown from a seaplane ramp at downtown Manhattan.

The new C-38 was quite a bit different from the earlier machines. It featured an increased wheel tread of 12 in., and a new windscreen; the Pyrolin being replaced by Plexiglass. The wing flaps were deleted, and a hydraulically-actuated centralized flap fitted to the dorsal side of the fuselage. The tailwheel had a locking device, and the standard Warner engine was retained. The cost of the Airmaster had risen to $6,000.00, and sales were disappointing, only 15 being sold before the introduction of the C-145. The final C-38 being sold to Wein Airlines in Alaska.

CessnaC-145Unlike the earlier Airmasters, the horsepower of the engine was used to designate the type, rather than the year of introduction. The C-145 featured a new wing design, with electrically-operated flaps being mounted in a strengthened structure which incorporated larger wing tanks. The planform and airfoil remained unchanged. Hydraulic wheel brakes were incorporated for the first time in a Cessna aircraft. The flaps, needless to say, were more effective than on the C-38, and the prototype C-145 (s/n 450; NC 19464), was completed on 10 Sept. 1938 and promptly sold to Robinson Aerial Surveys of NYC. Painted red with blue trim, the aircraft had a lengthy career.

Following the final C-145, Cessna intorduced the final Airmaster variant, the C-165. Few airframe changes were made, despite the more powerful 165 hp Warner Super Scarab engine.The prototype, NX (later, NC), 19497 (s/n 466) was test-flown on 22 April 1939. The higher horsepower improved the Vmax. to 165 mph, and the Vc to 157 mph. A total of 82 C-145s and C-165s were built in 1939. One C-145 was exported to Rio de Janiero, Brazil, and a float-equipped C-145 was sent to Finland (s/n 464; OY-YNB). Additionally, three C-165Ds were built during 1941, fitted with 175 hp Warner Model D engines and Hamilton Standard constant speed propellers. During the Second World War, 8 Airmasters were impressed into the USAAF; the earlier variants being known as UC-77s, while late model C-165s became UC-94s. In 1940, one Airmaster was modified by General Motors Research Labratories to test the X-250, an eight-cylinder, two-cycle, water-cooled radial of 175 hp. The pistons were paired, two cylinders firing simultaneously. While the engine was functional, it made no inroads into the commercial market place. The “X” configuration, was nevertheless, practical. Tony LeVier did the test-flying of the all-red aircraft, which GM used up to 1945. The last one-hundred and eighty-sixth, and last C-165 was completed on 12 August 1941, being sold to Dr. Nolie Mumey of Denver, Colo. Wein Airlines operated C-165s in addition to a ski-equiped C-37. The design influence of the Airmaster is evident in post-war Cessna designs, particularly, the P 780, which evolved into the Cessna Model 190. But, this isn’t the end of the story…

During 1937, Eiler Christian Sundorph purchsed a Cessna Airmaster with the intent of racing the aircraft in the 1937 Bendix. Unfortunately, I was unable to learn only a few things about Mr. Sundorph’s life and aviation exploits. Substituting a new aluminum fuselage for the standard Cessna steel tube and fabric of the Airmaster, Mr. Sundorph, of Cleveland, Ohio, created the; “Sundorph Special,” or “A-1” racer. In 1932, he is known to have constructed a two-place monoplane (X 12886), powered by a 100 hp ACE (Cirrus) engine, under the aegis of the Sundorph Aeronautical Corp., of Cleveland, Ohio. However, details remain elusive. Still, there is some information on the “Special.” Registered as R 2599, (race number: “17”), the aircraft retained the wings, and apparently, the horizontal tail surfaces of the prototype Cessna C-34 (NC 12559). Another big change, was the installation of a Jacobs L-5; the power being increased from 145 hp (@ 2,050 rpm) of the Cessna C-34, to 285 hp at 2,000 rpm, an approximate increase of 50.8% over that of the C-34/C-37. The overall dimensions of the engine also increased. With the engine substitution, the diameter increased from 36.75 in. to 43.5 in., a 6.75 in. increase. The length of the Warner was only 28.75 in., but the Jacobs was much longer, being 39 in. in long. While both engines burned 73 octane fuel, the consumption of the Jacobs was somewhat less, burning 0.50 lb./hp-hr., while the Warner burned 0.58 lb./hp-hr. The oil consumption of the L-5 was; 0.015 lb./hp-hr., while the Warner burned 0.025 lb./hp-hr. The weights were significantly different. The Jacobs weighed in at around 525 lbs., and the Warner weighed; 306 lbs. Jacobs used a Stromber N.A. R7A carburetor, and two VMN7-DF Scintilla magnetos, while Warner used a Stromberg NAR-5A carburetor and two Scintilla MN7-DF magnetos with Champion M-4 spark plugs.

Statistics for the Sundorph are few and far between. While conducting research for this article, I heard from Mr. Wayne Muxlow. In e-mails exchanged with Mr. Muxlow, I learned that he currently owns the Cessna C-34 prototype, which Sundorph used for the conversion. Sundorph, also changed the undercarriage, to use unique inflatable “doughnuts,” placed inside the fuselage as shock absorbers. The horizontal stabilizer and elevators were retained, but the vertical fin and rudder were apparently modified. According to Dan Hagedorn at the Museum of Flight, the fuselage was destroyed during a wartime scrap drive. However, Mr. Muxlow states that the original C-34 components were reassembled after the war, and that he is the current owner.

A point which I could not reconcile, is the span. According to the information supplied by Dan Hagedorn, the Sundorph had a span of 33 ft., one-foot, two-inches shorter, than the standard span of the C-34. Mr. Muxlow, states that this information must be in error. Indeed, that does seem likely, given the greater diameter of the Jacobs engine fitted to the Sundorph. Just how the Airmaster wing was modified, if at all, remains unclear.

As to the new fuselage, the overall length is stated to be 29 ft. 0 in., according to Mr. Hagedorn, a significant increase over the 24 ft. 8.5 in. length of the Cessna Airmaster. Assuming the wing area was unaltered from 182 sq. ft., the wing loading and power loading are indeterminent due to the lack of information regarding the weight of the aircraft. Presumably, the 17.5 gal. (per wing) tanks were retained on the Sundorph. The attainable velocities are also difficult to determine, given the lack of data; with the exception of the race speed, given below.

According to Mr. Muxlow, Eiler Sundorph operated an FOB at Cleveland during 1934 -1935, which may be where he got the idea to modify a Cessna C-34. By 1937, the competition had radically changed. The Bendix, was won by Frank Fuller, flying a Seversky SEV-S2, (R 70Y, race number: 23) with an average speed of 258.24 mph, and a time of 7:54:27. Second, was Earl Ortman, flying the Keith Rider R-3 (NR 14215, race number: 4), with a speed of 224.83 mph, and a time of 9:49:22. Third, was Jackie Cochran, flying  a Beech D-17W (NR 18562, race number: 13). Fourth, Frank Sinclair, Seversky SEV-7 (N 18Y, race number: 63), speed; 184.92 mph, time: 11:02:33. Fifth, Milo Burcham, Lockheed Electra 12 (R 18130, race number: 20). In sixth place, Eiler Sundorph, “Sundorph Special” (R 2599, race number: 17), speed: 166.21 mph, time: 12:17:08. Joe Mackey, flying the Wendell Williams, did not finish.

As Eiler Sundorph dove to cross the finish line, the Cessna wings; obviously under great strain, developed aerodynamic flutter. Encountering this, Sundorph disassembled the aircraft, and it was never flown again. In November of 1941, he was killed flying a Bell P-39D at Wright Field. But, that isn’t quite the end of the story. According to the material I uncovered, the name; “Sundorph,” remained in use in the Cleveland area. I discovered that well into the 1980s, a pt. 135 airline was operated under that surname, and post-World War Two, there was a flying school by that name. The airline, “Sundorph Airlines,” (aka: the “Sundorph Aeronautical Corporation”), apparently used Beech Model 18s and  Lockheed Lodestars. A Sundorph Airlines Schedule for 1983 was also unearthed. It states that they had been around for 57 years, and flew two routes; Cleveland to Detroit, and Cleveland to Columbus, the Sundorph; “Shuttle Air Service,” charging $45.00 for a one-way ticket to Detroit. Perhaps, one of the most interesting articles was a 1963 account of a Sundorph Aeronautical Corp. Hughes Model, 269 being used to symbolically haul the final bucket of cement to an apartment complex named; “Winton Place,” in Cleveland. This event, which took place on 7 Oct. 1963, marked the completion of the first building accessible by; land, air and water, in Cleveland. As late 14 January 1989, The Plain Dealer (Cleveland newspaper, p 2B) contained a story about pollution at the Cleveland Hopkins Airport, resulting in the release of toxic chemicals and human waste into the Abrams Creek. The Sundorph Aeronautical Corporation was named as the tenant most responsible for the pollution.

In addition to Mr. Wayne Muxlow; David Helmso, Dan Cullman, Bradford Payne, and Roy Oberg; correctly identified this aircraft.

Finally, I would be remiss if I did not mention the actor Robert Cummings, and his connection to the Cessna Airmaster. While at Joplin High School, he was allegedly taught to fly by his Godfather, none other than Orville Wright. This internet myth, is undoubtedly because Orville would occasionally sign the licenses of pilots, if he was asked. A check of the Papers of Wilbur and Orville Wright, do not include any correspondence between Orville and Cummings, and it is dubious that he could have had any other connection to Orville Wright.  He soloed on 3 March 1927 (another source states that it was 1929), and received the first Flight Instructor’s license in the United States (unconfirmed). Prior to 1927, licenses were issued by the Aero Club of America, under the aegis of the Federation Aeronautique Internationale. Starting in 1927, they were issued by the Aeronautics Branch of the Dept. of Commerce. Cummings, attended the Carnegie Institute to study aeronautical engineering, but was forced to drop out from lack of funds. During the Second World War, he became a flight instructor with the U.S. Army Air Force in 1942, and after the war, eventually became a Captain in the USAF Reserves.

Bob Cummings starred in; Dial M for Murder, The High and the Mighty (Directed by William Wellman, a former member of the Lafayette Flying Corps), and also played in; Beach Party, in which he flies a Piper Cub from a beach (fitted with balloon tires). In addition to his movie work as an actor, he also had two television series in which he piloted aircraft. His last show; The New Bob Cummings Show, ran from 1961-1962. In the series, he is depicted as the owner of an Aerocar (N 102D). Perhaps, he is best remembered for his appearance in a 1960 episode of The Twilight Zone, loosely based on the (then) recent discovery of the B-24D, “Lady Be Good.” In the episode; “King 9 Will Not Return,” his guilty conscience takes him to the scene of the wreckage of his B-25, where he is haunted by apparitions of his dead crew. At any rate, Bob Cummings, is known to have flown a Cessna Airmaster nicknamed; “Spinich II,” in California, during the late ’30s. A life-long vegitarian, he was married 5 times, and lived 80 years, dying in 1990. A photo of his Cessna C-37 (s/n 369; NC 18550) appears on p 96 of the excellent book: Madcaps, Millionaires, and “Mose;” A Pictorial History by John Underwood.


Angle, Glenn D. AEROSPHERE’S MODERN AIRCRAFT ENGINES. New York, New York: Aircraft Publications, 1941, pp B-19 – B-20 and B-49 – B-51.

Juptner, Joseph. U.S. CIVIL AIRCRAFT VOLUME 7 (ATC 601 – 700). Fallbrook, California: Aero Publishers, Inc., 1978, pp 84 – 86 and 236 – 238.

Juptner, Joseph. U.S. CIVIL AIRCRAFT VOLUME 8 (ATC 701 – 800). Fallbrook, California: Aero Publishers, Inc., 1980, pp 9 – 12.

Underwood, John. MADCAPS, MILLIONAIRES AND “MOSE.” Glendale, California: Heritage Press, 1984, p 96.


Matt, Paul R. Cessna Airmasters. Historical Aviation Album Volume VI. 1969, pp 14 – 23.


Hagedorn, Daniel. E-mail regarding the Sundorph “Special.”

Muxlow, Wayne. E-mails regarding the Sundorph “Special,” and his Cessna C-34 Airmaster.

www.imdb.com. Biographical information on Robert Cummings, and his acting career.

www.wikipedia.com. Birgraphical information on Robert Cummings.

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