HUNGARIAN GLIDERS
1933-2000
Type designation: R-08a
Name: A-Pilis
Designer: Ernő RUBIK
Class: Training
General arrangement: High, strutted wing, open canopy, traditional tail unit
Crew: 1
First flight: March 19, 1939
Manufacturer: Aero Ever Kft., Esztergom
Number of built: 1



Short history:
One example of Wolf Hirth's Wolf had arrived to Hungary in 1937 and became very popular among glider pilots. Ernő Rubik designed a new glider, the Pilis, to meet the demand for such kind of gliders. The new design was based on the line of Szittya gliders but with reduced dimensions. The prototype, which later got the type designation of R-08a, had first flown on March 19, 1939. New versions followed and the Pilis was one of the gliders built in greatest number in Hungary.
Of the version R-08a, which inherited the Szittya's gull form wing and "curved" fuselage outline, only one example was built. The curved form of the fuselage caused problems with proper flaring, and a new version, the R-08b, was developed with "straight" fuselage outline to eliminate this disadvantage.
The type was authorized for bungee-cord, aerotow and winch launching, cloud flying and basic aerobatics.

Structure:  All wooden
   Wing:
The glider had a one spar, single streamlined steel tube strutted wing with a plywood covered torsion resistant box structure in front of the main spar. The ribs had flat lattice frame structures. No airbrakes were fitted on this version.
   Fuselage:
The fuselage was a plywood covered semi-monocoque structure strengthened with ribs and longerons. The canopy was removable and was fitted with a simple windshield. The landing gear consisted of a main and a small aft skid both rubber dumped.
   Tail unit:
The tail unit had traditional arrangement and a structure similar to the wing. On the elevator a trim tab was fitted.


Larger picture

Dimensions:
   Wing:
     Span, m: 13,6
     Area, m2: 15,7
     Aspect ratio: 11,78
     Chord (root), m: 1,2
     Chord (tip), m: 0,75
     Airfoil (root), m: Gö 533
     Airfoil (mid-span), m: W-339
     Airfoil (tip), m: W-299
     Dihedral, degree: Outer panels: 0
     Sweep, degree: 0
     Washout: Aerodynamic and -3° geometric
   Aileron:
     Span, m: 3,75
     Mean chord, m: 0,264
     Total area, m2: 2,82
     Balancing: None
   Horizontal stabilizer:
     Span, m: 3
     Area, m2: 2,26
   Elevator:
     Span, m: 3
     Area, m2: 1,54
     Airfoil: Symmetrical
     Balancing: None
     Trim: Yes
   Vertical stabilizer and rudder:
     Total area, m2: 1,18
     Rudder area, m2: 0,93
     Balancing: Aerodynamic
   Fuselage:
     Length, m: 6,0
     Width, m: ?
     Height: 1,65
     Cross section, m2: ?
   Landing gear:
     Type: Skid
Masses:
   Wing, kg: ?
   Fuselage, kg: ?
   Tail unit, kg: ?
   Empty glider, kg: 150
   Gross, kg: 250
   Ballast, kg: None
   Wing loading, kg/m2: 15,9
Speeds:
   VNE, km/h: 160
   Max. aerotow speed, km/h: 100
   Max. winch speed, km/h: 70
   Max. speed in rough air, km/h: ?
   Stall speed, km/h: ?
Performance:
   Min. sink, m/s (at gliding speed, km/h): 1,0/?
   Best L/D (at gliding speed, km/h): 17/?
Start methods: Bungee, 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