HUNGARIAN GLIDERS
1933-2000
Type designation: R-08d
Name: D-Pilis
Designer: Ernő RUBIK
Class: Training
General arrangement: High, strutted wing, open (later closed) canopy, traditional tail unit
Crew: 1
First flight: 1943
Manufacturer: Aero Ever Kft., Esztergom
Number of built: 193



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 first version, which later got the type designation of R-08a, had first flown on March 19, 1939. New versions - R-08b and R-08c - followed and this type was one of the gliders built in greatest number in Hungary.
With the first three versions of the Pilis family no airbrakes were fitted. However airbrakes on high performance gliders were common at the early '40s and it became necessary to use airbrakes on training gliders as well. To comply with this requirement a new version fitted with airbrakes was developed. It was originally designated as R-09 but later it was re-designated as R-08d. The first glider flew in 1943. This type also had a removable open canopy with windshield and skids as landing gear. Serial production started only after the war in 1948 and 65 gliders were built of this version.
The R-08d version was subsequently modified several times. The Essler-type towing hook making possible high winch launches was fitted, the first of this kind in Hungary. In 1953 a new serial production started. On this sub-version a fix wheel was fitted just behind the main skid and on the two sides of the fuselage special hooks for Y-form launching wire were fitted for high-winch launching. 97 gliders were built of this sub-version. The second half of the series were fitted with removable closed canopies.
In 1956 a new series of 31 gliders was commenced. Again half of them were fitted with open, and half of them with closed canopies. This sub-version was also known as B-2. One of the B-2s was fitted with a 18 kW Porsche engine located on a parasol on top of the wing and driving a pusher propeller. This version was known as Győr-3 Motor-Pilis.
All sub-versions of R-08d were authorized for bungee-cord, aerotow and winch launching, cloud flying and basic aerobatics.


Structure:  All sub-versions had similar all wooden structure.
   Wing:
The one spar, streamlined steel tube strutted wing had a plywood covered torsion resistant box structure in front of the main spar. The ribs had flat lattice frame structures.
   Fuselage:
The fuselage was a semi-monocoque structure strengthened with ribs and longerons.
   Tail unit:
The tail unit had traditional arrangement and a structure similar to the wing.

Larger picture | 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 229
     Dihedral, degree: 1,5
     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
   Flap:
     Type: None
   Airbrakes:
     Type: Göppingen
     Position (upside/downside): u/d
     Total area, m2: 0,48
     Position, % of chord: 0,375
   Horizontal stabilizer:
     Span, m: 3
     Area, m2: 2,26
   Elevator:
     Span, m: 3
     Area, m2: 1,54
     Airfoil: Symmetric
     Balancing: None
     Trim: Yes
   Vertical stabilizer and rudder:
     Total area, m2: 1,18
     Rudder area, m2: 0,93
     Balancing: Aerodynamic
   Fuselage:
     Length, m: 6,75
     Width, m: 0,59
     Height: 1,07
     Cross section, m2: 0,605
   Landing gear:
     Type: Fixed
     Wheel diameter, m: 0,26
Masses:
   Wing, kg: 88
   Fuselage, kg: 58
   Tail unit, kg: 7
   Empty glider, kg: 163
   Gross, kg: 250
   Ballast, kg: None
   Wing loading, kg/m2: 15,9
Speeds:
   VNE, km/h: 170
   Max. speed with open airbrakes, km/h: 170
   Max. aerotow speed, km/h: 100
   Max. winch speed, km/h: 70
   Max. speed in rough air, km/h: 100
   Stall speed, km/h: 48
Performance:
   Min. sink, m/s (at gliding speed, km/h): 0,95/60
   Best L/D (at gliding speed, km/h): 18/65
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