Younkin-Dake Mullicoupe

Mullicoupe
Mullicoupe at Vintage Aero Flying Museum, March 2007
Role	Light Trainer and Racer
Manufacturer	Younkin-Dake
Designer	Jim Younkin
Introduction	1989
Status	2 still flying 3 flying in 2003
Primary user	Civil Aviation
Number built	3

A Younkin-Dake Mullicoupe is a two-place monoplane modeled on a Monocoupe and a Mister Mulligan aircraft.

History

Jim Younkin of Springdale, Arkansas completed a frame of this aircraft in 1989 and a homebuilt model earlier in 1985 with the help from Bud Dake. Three Mullicoupes were flying by 1997. The idea of this design came to Younkin and Dake at the Ottumwa, Iowa Antique Airplane Association's Fly-In in 1982 after a discussion about Younkin's Mister Mulligan. Bud Dake suggested they design a 2 seat aircraft which would be as fast as the Mister Mulligan but powered by a smaller P&W R-985 engine. Younkin then designed a scale model which was somewhat of a cross between the Benny Howard-designed Mister Mulligan but with the fuselage shape of a Monocoupe. The Mullicoupes are a clean-sheet design utilizing a steel tube fuselage double-covered in fabric with built up wood wings skinned in aircraft plywood. The airfoil used on the Mullicoupe is the NACA 23012 having a chord of 63", but with an elliptical and tapered planform. The flaps are full Fowler flaps that travel on hidden hinges built into the wings, which is another Younkin original design. Propeller is a Hamilton Standard 2D30 of 102" in diameter with the -6167 blade airfoil.

Today

Three original Mullicoupes were created and a fourth was started but never finished. At present they are owned by Mark Holliday, Mr. Younkin himself, and Red Lerille. A fourth Mullicoupe, owned by Stein Bruch of Minnesota, is being completed with the assistance of Jim Younkin. The Black/Red Mullicoupe which was completed by Bud Dake (deceased) is owned by Mark Holliday, is on display and flies at the Vintage Aero Flying Museum, Platte Valley Airpark, Hudson, Colorado. Mr. Holliday is known to travel extensively with this black and red Mullicoupe, making appearances at fly-ins around the American Midwest.

The Red Younkin-owned Mullicoupe suffered a loss of power which resulted in a forced landing in a field near Siloam Springs, Arkansas on November 10, 2009. The aircraft suffered significant damage, but is currently being repaired.

^{[1] [2]}

Original specifications

• Engine: Pratt & Whitney R-985 radial
• Power: 450 hp
• Cruise speed: 200-225 mph at 14,000 ft

Mullicoupe tail view at Vintage Aero Flying Museum, March 2007.

Details

Source: PirepMullicoupe^[3]

• Wingspan: 29 ft 3 in
• Fuel capacity: 150 gal
• Wing loading: 24 to 27 lb/sq ft, depending on fuel
• Cruise flight: 7 hrs
• Deck angle: 15 deg

New version

• Engine: Pratt & Whitney R-985 with Hornet or Wasp impeller geared at 12:1 blower to crank ratio (stock 985 is 10:1)
• Cruise speed: 250 mph at 15,000 ft

Sources

• EAA's Timeless Voices of Aviation, 2003 Archives article: Voice of the Week - Jim Younkin, written Sept. 23, 2003.

1. ^ Stein Bruch's Mullicoupe
2. ^ Wrightool.com's Mullicoupe
3. ^ Airbum.com's PirepMullicoupe

See also

• Monocoupe 90 monoplane
  

Related development

• Howard DGA-6 (Mister Mulligan)