Glass wing 304

Glass wing 304
Type:	Glider
Design country:	BR Germany
Manufacturer:	Glass wing glider construction
First flight:	May 10, 1980
Production time:	1980-1982
Number of pieces:	62

The Glasflügel 304 is a single-seat glider of the racing class from the manufacturer Glasflügel Segelflugzeugbau . Occasionally the aircraft is also mistakenly referred to as the H-304 glass wing. Today successor models of the aircraft are available as HPH 304 from the Czech manufacturer HpH Sailplanes .

history

In the autumn of 1979, the then GRP-experienced glider manufacturer under the management of Erich Weinzierl began with the development of a Mosquito successor. Martin Hansen, one of the designers of the SB 11 , relied on a new wing profile with flaps specially developed in Braunschweig for this aircraft and on design studies by Detlef Kirchner (Cologne) for the cockpit area . In order to keep the risk as small as possible, Glasflügel wanted to test the new profile on an airplane. For this purpose, a mosquito wing with micro balloons was brought to the calculated profile contour and then measured with a mosquito fuselage in Braunschweig. The expectations of K. H. Horstmann and A. Quast in their latest profile were confirmed. Now you could go to the hull at the end of February 1980. The nose and cockpit have been completely redesigned. During the following months up to the first flight (on May 10, 1980 with M. Hansen in Nabern ), work was carried out on the fuselage and the new wing shapes in parallel. Incidentally, the negative molds for the grand piano were made entirely of plastic for the first time. Glasflügel thus achieved a significantly better dimensional accuracy and long-term stability.

When Glasflügel went bankrupt in 1982, production of the 304 ended after 62 pieces.

In the mid-1990s, the molds for production were taken over by the Czech company HpH. The 304 has since been rebuilt as HpH 304 CZ and various other versions of the aircraft were created as part of the facelift.

construction

The profile HQ 010-16.42 with 16.42% relative thickness is much better in its climb performance than all profiles used in the past years for "racing class" aircraft (lowest sinking at 31 kg / m²: 0.57 m / s). Nevertheless, the aircraft achieved a glide ratio of more than 42, probably even 43. Glasflügel made a conscious decision to use the greater thickness compared to other new profiles. Since the high-speed flight performance is still favorable, there was also the advantage of being able to build the aircraft with a reasonable unladen weight (235 kg) entirely with fiberglass-reinforced plastic . In addition, there is the ideal prerequisite for producing the wings from carbon fiber reinforced plastic (CFRP construction) with the same total weight and achieving a wingspan of 17 m with clip- on wings without having to accept any restrictions (for example with take-off weight and maximum speed). This was firmly planned for spring 1981.

With the more pointed fuselage nose, Glasflügel followed the general trend without having to forego the nose coupling . The “revolution” took place within the fuselage shell : on the 304, the instrument panel with the hood hinged at the front (supported by a gas spring) folds up completely. A previously unknown easy entry and exit became possible. The hoses and cables for the instruments and the radio go through the pivot point of the canopy attachment and are laid in a protected manner in the aircraft. There are no more disturbing parts in the hull and the pilot only needs to use the stick to get on without having to thread his legs. The oxygen monitoring displays are built into a console under the control stick and are easy to read.

Further technical features are the rear edge rotary brake flaps combined with the flaps and the parallelogram control with trim button.

The 304 has a retractable landing gear.

Technical specifications

Parameter	Data
span	15.00 m
Wing area	9.88 m²
Wing extension	22.78
Hull length	6.45 m
Trunk width	0.62 m
Torso height	1.36 m
Empty mass	235 kg
Max. Load hull	135 kg
Max. Water ballast	115 kg
Max. Takeoff weight	450 kg
Max. Wing loading	45.55 kg / m²
Top speed	250 km / h
Stall speed (310 kg)	60 km / h
Stall speed (450 kg)	73 km / h
Lowest sink (310 kg)	0.57 m / s at 77 km / h
Lowest sink (450 kg)	0.69 m / s at 93 km / h
Glide ratio (450 kg)	approx. 43 at 116 km / h

See also

• HPH 304

literature

• RH Johnson: A Flight Test Evaluation of the 304CZ Sailplane. Soaring, July 2000 (English).
• F. Thomas: Fundamentals of Sailplane Design. College Park Press, 1999.
• M. Simons: Gliders 1965-2000. Eqip, 2004.

Web links

• Type approval of the glass panels 304 - EASA-TCDS-A.241 (PDF; 353 kB)
• Type approval of the glass wing 304CZ - EASA-TCDS-A.030 (PDF; 179 kB)
• Glass wing 304 at the start on Hahnweide
• Website of the company HpH Ltd
• Glass Wing 304 on the Sailplane Directory website
• Armin K .: Die Glasflügel 304. segelflug.de, accessed on February 22, 2012 (test report). 

Individual evidence

1. ↑ glasflügel 304 (PDF; 1.1 MB) Glasflügel airplane a. Vehicle construction GmbH. Retrieved on February 22, 2012.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.