Aircraft Quiz #58

[Doug Robertson]

Name the built/flown aircraft make and model with twin balanced rudders that set an historic "First". Note: only one make/model of aircraft can qualify as this aviation "First".

1a. First year of manufacture?, 1b. Make of aircraft?, 1c. Model nomenclature?

2. Designer's name?

3. What was the aviation "First" of this aircraft?

As usual, details/specs will follow the only correct answer set.

[sparrow9]

I am not sure about this:

1a: 1939, 1b: Erco, 1c: Ercoupe
2: Fred Weick
3: it had only two controls for all three axes, no rudder-pedals. It was " non-spinnable"

John

[Doug Robertson]

Thank you, but NO on all answers.

The ERCO Ercoupe or ALON Aircoupe or Forney AirCoupe or Air Products F-1A Air-Coupe or Mooney M-10 Cadet models (same basic aircraft design-successively) (if NOT of the original rudderless Simplimatic design) do NOT have BALANCED rudders. Mooney built/sold first the purchased design twin rudder (non-Simplimatic) version, then a few with the single vertical Mooney characteristic tail with unbalanced rudder.

This quiz is about an aircraft with twin BALANCED rudders, which have a part of each rudder FORWARD of the swivel. or hinge plane, which aids and lightens control forces when activated for coordinated flight turns with the rudder pedals, or during forward slips.

[Doug Robertson]

OK, I have here achieved another goal. A "Stumper" with over 500 views and no correct answers. Here are the correct, and only right answers.

1a. 1926, 1b. The Johnson Aircraft Division of Johnson Airplane Supply Company of Dayton, Ohio, 1c. Johnson "Twin Sixty".

2. Dave E. Dunlap was the aircraft design engineer and Vice President of the company. (He later joined Douglas Aircraft in 1936).

3. The Johnson Twin Sixty was the very first certificated aircraft awarded an Approved Type Certificate by the US Department of Commerce that had a design element of Twin Balanced Rudders. The A.T.C. was granted in March of 1927 as ATC #3. Prototype was first flown in 1926.

The Johnson Twin Sixty was interesting in several unconventional ways. It was a tandem open cockpit small biplane with hull-shaped streamlined fuselage with twin PUSHER engines mounted in strut-braced nacelles. Fuselage was welded steel framework, fabric covered, with some duraluminum areas. Biplane staggered wings were of wooden spars and ribs, fabric covered. Interplane struts were steel with balsa-faired leading edges. The pusher props were metal by Curtiss-Reed, although wood props were also used.

Excellent visibility for the pilot as the cockpit was forward of the positive stagger wings and the rear cockpit had an access door of dural sheet, which was also used elsewhere for streamlining. The tail group had a straight horizontal stabilizer with two balanced rudders at the very ends of it. The fixed rudders' area were small, with larger-area balanced rudders above and behind the fixed rudder portions. This was a novelty in a small aircraft at the time, but used in some early larger commercial designs.

The straight axle and spreader bar main wheel landing gear were fastened about fuselage width, with rubber disc shock-absorbers in compression. Tail wheel was originally a tail skid, later a fixed none-swiveling smaller wheel.

Gravity fed tanks above each engine were in the upper wing. Direct gravity, no cross-feed capability. Twin air-cooled pusher-mounted engines were the British Bristol "Cherubs" rated 30-36 Horsepower each.

No information remains as to production numbers, only evidence/documentation of the approved prototype remains.

Specs and Performance

Power: two Bristol Cherubs, 30-36 Hp each-pushers
Wingspan: Upper & lower, 28' each
Wing area total: 194 sq. ft.
Chord of both: 45"
Fuselage length overall: 21'
Height: 7'10"
Empty weight: 800 lbs
Useful load: 520 lbs
Weight gross: 1,320 lbs......(same as today's LSA category).
Max speed: 75-85 mph
Cruise speed: 60 mph
Landing speed: 25-30 mph
Rate of Climb: in Dayton, Ohio 550 ft/min.
Ceiling: 8,000 ft
Fuel capacity: 25 gals.-12.5 each tank.
Range: 480 miles

****Errata: I apologize for getting the Bristol Cherub horsepower initially listed incorrectly, partly because of incomplete information initially. The true horsepower is 30-36 Hp each, hence the Twin 60 Sixty name, a bit confusing. Information from 1926-'27 is less detailed than more current aircraft, and the corrected information on this engine is above. Aircraft performance is certainly more in line with the lower horsepower, now corrected on 12 Sept. 2015.

I thank all who viewed this quiz.

[red750]

Photos can be found here.

http://aviadejavu.ru/Site/Crafts/Craft33846.htm

Peter.

[Doug Robertson]

Again, Thank you, Peter! Links to photos of quiz aircraft are always welcome. That adds so much to the quiz value of aircraft history/education.