HUNGARIAN GLIDERS
1933-2000
Type designation: R-15F
Name: Fém-Koma
Designer: MIHÁLY-BÁNVÖLGYI-BENDE-MAJOR
Class: Dual-training
General arrangement: Cantilever, mid-wing, side-by-side closed cockpit, traditional tail unit
Crew: 2
First flight: Jun 1958
Manufacturer: Sportárutermelő Vállalat, Esztergom
Number of built: 1



Short history:
The staff of the Sportárutermelő Vállalat had gained experience during the construction of Rubik's first all-metal glider, the R-23 Gébics. In 1957 József Mihály, Lajos Bánvölgyi, Lajos Bende and Ferenc Major of the design office of the factory redesigned the R-15b Koma as an all-light-metal glider. The new glider got the designation R-15F Fém-Koma (Metal-Koma). The new version retained the arrangement and characteristics of the original Koma, however small differences occurred due to the metal technology. The glider first flew at Jun 1958. Up to Jun 1964 the glider gained 520 flight hours and accomplished 6275 launches without any mishap. Meanwhile the R-26S Góbé appeared and the Fém-Koma was never built in series.



Structure:  All-metal
   Wing:
The cantilever wing's planform was rectangular. The wing structure as well as the wing-fuselage connection of the R-23 Gébics was applied and the wing were not foldable. Slotted Frise type ailerons were used.
   Fuselage:
The fuselage was similar to the R-15b, however a one-piece, forward opening canopy was applied.
   Tail unit:
The tail surfaces got rectangular forms.

Larger picture

Dimensions:
   Wing:
     Span, m: 13,35
     Area, m2: 17,12
     Aspect ratio: 10,12
     Chord (root), m: 1,3
     Chord (tip), m: 1,3
     Airfoil (root), m: Gö 549 mod.
     Airfoil (mid-span), m: Gö 549 mod.
     Airfoil (tip), m: Gö 549 mod.
     Dihedral, degree: 3
     Sweep, degree: 0
     Washout: None
   Aileron:
     Span, m: ?
     Mean chord, m: ?
     Total area, m2: ?
     Balancing: Aerodinamic
   Flap:
     Type: Plain
     Area, m2: ?
     Relative length, %: ?
     Movement (+/-), degree: 15/60
   Airbrakes:
     Type: None
   Horizontal stabilizer:
     Span, m: ?
     Area, m2: ?
   Elevator:
     Span, m: ?
     Area, m2: ?
     Airfoil: Special
     Balancing: None
     Trim: Yes
   Vertical stabilizer and rudder:
     Total area, m2: ?
     Rudder area, m2: ?
     Balancing: None
   Fuselage:
     Length, m: 8
     Width, m: ?
     Height: ?
     Cross section, m2: ?
   Landing gear:
     Type: Fixed
     Wheel diameter, m: 0,26
Masses:
   Wing, kg: ?
   Fuselage, kg: ?
   Tail unit, kg: ?
   Empty glider, kg: 206
   Gross, kg: 386
   Ballast, kg: None
   Wing loading, kg/m2: 22,55
Speeds:
   VNE, km/h: 150
   Max. aerotow speed, km/h: ?
   Max. winch speed, km/h: ?
   Max. speed in rough air, km/h: ?
   Stall speed, km/h: 60
Performance:
   Min. sink, m/s (at gliding speed, km/h): 1,05/69
   Best L/D (at gliding speed, km/h): 19,65/84
Start methods: Winch, Aerotow



Origin of data and 3-view drawing:
Jereb Gábor: Magyar vitorlázó repülőgépek, Műszaki Könyvkiadó, 1988, Budapest
(Gábor JEREB: Hungarian Gliders, Technical Publishing House, 1988, Budapest)

Gábor FEKECS E-mail: fekecs.gabor@t-online.hu