Coarse G 102

Coarse G 102
Grob Astir CS on the Mönchsheide glider airfield
Type:	Glider
Design country:	BR Germany
Manufacturer:	Rough
First flight:	1974

The production of gliders at Grob Aircraft AG from Mindelheim in Swabia began in 1971 with the license production of 200 Cirrus gliders . In 1973 the G 102 was launched, which was manufactured in many variants.

Further developments were the two-seater G 103 and the single-seater of the G-104 series, which became known under the name Speed-Astir .

Common to all variants were the 15 m wingspan and the T-tail unit. The maximum permissible speed (V _NE ) is 250 km / h, the maneuvering speed 170 km / h. The glide ratio is between 36 and 38. The G 102 is approved for simple aerobatics , the maximum load multiples are + 5.3 / −2.65 g .

Versions

Astir CS during winch launch

• Astir CS
• Astir CS 77
• Astir CS Jeans (Club Astir)
• Standard Astir II
• Club Astir II
• Standard Astir III
• Club Astir III
• Club Astir IIIb

Astir CS

The Grob Astir CS (first flight December 19, 1974) is the first self-designed aircraft of the aircraft manufacturer Grob (today Grob Aircraft). a. Hermann Nägele and Richard Eppler, who had already made a name for themselves with the construction of the Fs24 Phoenix. The basis for the hull of the Astir CS was the Schempp-Hirth Cirrus, the shape of which was still available due to the license building. It was made of plastic and is characterized by a very spacious cockpit and very good-natured slow flight characteristics as well as its acceptable flight performance. It appeared at the turn of the year 1974-75.

Astir in flight

The Astir CS was in competition with the ASK 18 (glide ratio about 33). Since the ASK 18 was made in a mixed construction and had lower performance than the Astir CS (glide ratio 38), the Astir prevailed at a small additional price. The Astir CS is attractive to clubs and private pilots thanks to its good price-performance ratio (between 7,000 and 13,000 euros, depending on the condition and equipment) and its classification in the glider index list (index 96). In addition, the CS is designed for tall pilots up to 2 meters. The Astir CS is used for advanced training and for cross-country flights. The production of the Astir CS was stopped in 1977 after a series of 535 aircraft in favor of the newly designed Astir CS 77 - later called "Standard".

Astir CS 77 / Astir CS Jeans

The Astir CS 77 "Standard Astir" (first flight March 26, 1977) is a revised version of the Astir CS, whose cockpit has become more streamlined but narrower. The wing has not been changed, but the slight forward sweep of the predecessor has been removed and adapted to the new fuselage at the fuselage transition. Furthermore, the profiles of the elevator and vertical stabilizer were changed. This leads to a changed flight behavior compared to the CS, especially with regard to the now significantly reduced maneuverability around the vertical axis. The tailplane connections and control levers for flaps and landing gear have also been modified.

Astir CS Jeans

The Jeans Astir (sometimes referred to as Club Astir) is a version of the CS 77 with a fixed chassis and without water tanks so that it can also compete in the club class. The definition at the time allowed no retractable landing gear and no water tanks in the wings. There were also concerns about the use of retractable undercarriages for training operations, which were considered confusing for the student. It gets its name from the interior, which is largely made of denim - jeans fabric.

Standard Astir II / Club Astir II

The Standard Astir II is the next evolution of the Astir range, in which some features of the Speed ​​Astir have been adopted. It has a new, sleeker hull that largely matches the hull of the Speed ​​Astir IIb. The biggest change from the Speed ​​Astir is a one-piece hood. The wings were largely taken over from the previous model, but the ailerons, like the wing flaps on the Speed ​​Astir, are designed as gapless elastic flaps. The ailerons were extended to the edge curve and this was pulled down like the Twin II.

The Club Astir II was designed in the same way as the Jeans Astir, that is, it corresponds to a standard Astir II without water tanks and has a fixed chassis.

Astir III

Standard Astir III - N17999

G 102 Club IIIb of the LSC Babenhausen in the summer of 1991 after landing outside

The Astir III is a further development of the Astir II. In contrast to the previous models, the Astir III has a tail wheel instead of the fixed tail.

For these variants, the maximum permissible speed was temporarily set at 165 km / h in 2001 with a technical notification from the manufacturer. This was due to a few incidents of elevator flutter at high speeds. The restriction could be lifted again by installing a mass balance.

Standard Astir III

A copy of this type is on display at the National Air and Space Museum (NASM) in Washington, DC .

With this glider, Robert Harris reached an altitude of 14,938 m over the mountains of the Sierra Nevada on February 17, 1986 - this FAI record lasted for 20 years.

Club Astir III / b

As with the previous models, the club version of the Astir III is delivered without tanks for water ballast and retractable landing gear. Compared to the Club Astir IIIb , the main landing gear of the Club Astir III variant is attached further forward, which means there is no need for an additional nose wheel.

Technical specifications

	Astir CS	Standard Astir II	Club Astir II	Standard Astir III	Club Astir III
Hull length	6.47 m	6.80 m		6.75 m
span	15 m
Wing area	12.4 m²
Wing extension		18.2
Empty mass	255 kg	260 kg	255 kg	approx. 260 kg
Max. Takeoff weight without water ballast	380 kg
Max. Takeoff mass with water ballast	450 kg		-	450 kg	-
Wing loading	26-36 kg / m²			Max. 30.6 (without water) or 36.3 kg / m²	Max. 30.6 kg / m²
Max. Water ballast	100 l	90 l	-	100 l	-
Top speed	250 km / h
Maneuver speed	170 km / h
Slightest sinking	0.6 m / s at 75 km / h	0.58 m / s at 75 km / h	0.6 m / s at 75 km / h	0.62 m / s at 76 km / h
Glide ratio	37 at 95 km / h (350 kg)	37.5 at 95 km / h	36 at 95 km / h	36 (without water at 92 km / h) to 38 (with water at 105 km / h)	36 at 92 km / h
Glider index	96	100	98	100	96
Max. g load				+5.3 to −2.65 g (at maneuver speed)

See also

• List of aircraft types

Web links

Commons : G-102 Series  - Collection of Images

• Grob Aircraft AG website
• Type certificate Grob Sailplanes - EASA-TCDS-A.250 (PDF; 452 kB)
• Service successor for Grob gliders

Individual evidence

1. ↑ Astir II advertising brochure. Archived from the original on January 24, 2005 ; Retrieved March 11, 2009 . 
2. ↑ ^{a b} Astir III manual
3. ↑ LTA 2001-317 / 4 (PDF)
4. ↑ B. Grob Flugzeugbau: Flight manual for the Astir CS glider. Rev 9, Nov 28, 2005
5. ↑ B. Grob Flugzeugbau: Flight Manual GROB G 102 Standard Astir III. (PDF; 261 kB) October 1982