IS-29, IS-31, and IS-33
IS-29D2
Role	Club-class Sailplane Type of aircraft
National origin	Romania
Manufacturer	ICA
Designer	Iosif Șilimon
First flight	April 1970
Number built	>200

The ICA IS-29 was a sailplane built in Romania in the 1970s. The prefix IS comes from Iosif Șilimon, the Romanian IAR (Industria Aeronautică Română) aeronautical engineer who designed it.

Design and development

The 15-metre (49ft 3in) single-seat variant of the IS-28 series, the IS-29D2 single-seater has retractable gear, camber-changing flaps and Hütter-type airbrakes on the upper wing surface only. The T-tail has a fixed stabilizer and elevator. The –29D model is of all-metal construction while the earlier –29B has wooden wings. Developments include 19 metre (62 ft) -29E2 and 20 metre (66 ft) -29E3 versions and a flapless, fixed gear 16.5-metre (54 feet) ‘club’ model -29G.

The IS-29 was also produced in a motorglider version, designated the IS-29EM. This shared the low-set wings and three-point undercarriage of the IS-28M2, and the new wings of the IS-28MA.

Variants

• IS-29
  • IS-29B - wooden wings of 15-metre span
  • IS-29D
    • IS-29D2
      • IS-29D2 Club - Club-class version of IS-29D2
  • IS-29E - open class version with ballast tanks
    • IS-29E2 - version with 19-metre wings
    • IS-29E3 - version with 20-metre wings
  • IS-29EM - motorglider version
  • IS-29G - Club-class version with 16.5-metre wings
• IS-31 - IS-29 with 20-metre wings and linked flaps and ailerons
• IS-33 - IS-29 with tanks for 150 kg (300 lb) of water ballast

Specifications (IS-29D2)

Data from Jane's All the World's Aircraft 1988-89^[1][2]

General characteristics

• Crew: One
• Length: 7.3 m (23 ft 11 in)
• Wingspan: 15 m (49 ft 3 in)
• Height: 1.68 m (5 ft 6 in)
• Wing area: 10.4 m² (112 sq ft)
• Aspect ratio: 21.6
• Airfoil: root:Wortmann FX 61-163, tip:Wortmann FX 60-126/1
• Empty weight: 240 kg (529 lb)
• Max takeoff weight: 360 kg (794 lb)

Performance

• Stall speed: 65 km/h (40 mph, 35 kn) flaps down
• Never exceed speed: 225 km/h (140 mph, 121 kn) in smooth air
  
• Max rough air speed: 172 km/h (107 mph)
• Max aero-tow speed: 140 km/h (87 mph)
• Max winch-launch speed: 130 km/h (81 mph)
• g limits: +5.2 -2.65
• Maximum glide ratio: 37
  
• Best glide speed: 93 km/h (58 mph)
• Rate of sink: 0.65 m/s (128 ft/min)
  
• Minimum sink speed: 78 km/h (48 mph)
• Wing loading: 34.62 kg/m² (7.09 lb/sq ft)