Applebay Zuni

Last updated

Applebay Zuni
Role Glider
National origin United States of America
Manufacturer Applebay Sailplanes
Designer George Applebay
First flightNovember 1976 [1]
Number built20 [1]

The Applebay Zuni and Zuni II are single-seat, water-ballasted gliders designed to compete in the FAI 15m class.

Contents

In February 2015 the New Mexico State Legislature named the Zuni the Official State Glider. [2]

Design and development

The Soaring Society of America announced a sailplane design competition, in 1970, with the intention of giving American glider pilots the opportunity to fly competitive American designed and built aircraft in International competitions. George Applebay designed the Applebay Mescalero Open class glider for this competition, but the closing date passed long before the aircraft was ready. This competition stimulated George into designing a fibre-glass FAI 15m Class glider which emerged as the Zuni. [1] The aircraft is named for the Zuni people.

The Applebay Zuni, and the later refined Applebay Zuni II, as American designed gliders, were intended to compete with European fibre-glass gliders that have dominated 15m class competitions since the class was established. [3]

The Zuni was built using glass-fibre/epoxy resin composite materials, with particular attention to achieving laminar flow. Using the classic pod and boom layout developed by the German glider manufacturers, the Zuni uses a modified Wortmann 67 series aerofoil section in a relatively thin double taper wing, (19% at the root to relieve bending moments, rapidly thinning to 15% 0.9m outboard, 14% at the taper intersection and 13% at the tip) which is high set on the fuselage with 1o dihedral, (reducing drag from interference of the wing fuselage junction). The integrally moulded fin supports the slightly swept all-moving T-tail, with a small degree of reflex camber and a partially mass-balanced rudder. [1] The mono-wheel main undercarriage is manually retractable and a faired tailskid supports the rear fuselage on the ground. Water ballast is carried in integral tanks housed inside the leading edges of the wings, holding 219.8 litre (58 gal) 220 kg (484 lb). [3] Conventional control surfaces were fitted, with pitch and roll controlled by a sidestick, and rudder by pedals. The entire trailing edge consists of flaps inboard, out to about ⅔ span with ailerons outboard which also drooped when the flaps were deployed. [1]

Flight testing commenced in November 1976 with excellent results which generated much interest from the American gliding community which encouraged Applebay to start production by Aero Tek. Competition successes quickly showed that the Zuni was at least the equal of European built contenders, but the early success was marred by a fatal accident, in May 1977, caused by structural failure. [4] Aero Tek was forced out of business in 1978 but Applebay continued to develop the Zuni by forming a new company Applebay Sailplanes. [1]

After initial production George Applebay announced the Zuni II, with improved control, performance and lighter structure, introducing Kevlar (aramid fibre/epoxy) main spars and carbon-fibre (Carbon-fibre/epoxy), in varying quantities as production continued, for wing structure and main undercarriage doors. The Kevlar spar was built in cooperation with DuPont and saved over 70 lb in the weight of the aircraft compared to traditional fiberglass layups of the time. [5] Other changes included a dihedral increase to 2o, tighter tolerances on the aileron control circuit, re-positioned mainwheel to improve ground handling, orthodox control stick to remove unwanted roll during high g manoeuvres, as well as a redesigned cockpit with forward opening canopy on parallel linkages.

Interest in the Zuni II was lacklustre, due to the lack of competitiveness, as well as the poor currency exchange rates of the early 1980s which allowed European gliders to be imported at lower prices than equivalent American goods. Total production of all Zuni aircraft reached 20 by the time production terminated in 1983. [1]

Operational history

Modest success in National competitions was repeated in world class competition, but legal issues over an early structural failure and the low level of investment prevented the Zuni from achieving its full potential. American glider pilots quickly rejected the Zuni for world class competition, but three Zuni II aircraft were leased by the Polish gliding team to represent Poland in the 1983 World Gliding Championships, with modest results.

In 1982, over Taos, New Mexico, Jerry G. Mercer acquired all of his Silver C (3) Gold (3) and two Diamond FAI gliding badges during one flight in a Zuni II, an accomplishment that had never been done before. After the record flight the Zuni II with a total flight time of 56 hours was donated to the Smithsonian Air and Space Museum. [3]

In 2009, Steve Leonard flew his Zuni II to first place in the Region 10 South Sports Class contest at Brenham, Texas [6]

As of March 2015, 14 Zunis continue to be listed on the US Federal Aviation Administration aircraft registry. [7]

Aircraft on display

Specifications (Zuni II)

Data from Sailplane Directory [9]

General characteristics

Performance

See also

Related Research Articles

<span class="mw-page-title-main">Schempp-Hirth Discus</span> German single-seat glider, 1984

The Schempp-Hirth Discus is a Standard Class glider designed by Schempp-Hirth. It was produced in Germany between 1984 and 1995 but has continued in production in the Czech Republic. It replaced the Standard Cirrus. It was designed by Klaus Holighaus.

<span class="mw-page-title-main">Schempp-Hirth Ventus</span> Type of aircraft

The Schempp-Hirth Ventus is a sailplane produced during 1980–1994 by Schempp-Hirth, a German sailplane manufacturer. It was designed by Klaus Holighaus and replaced the Schempp-Hirth Mini-Nimbus. Schempp-Hirth manufactured 613 Ventus sailplanes.

<span class="mw-page-title-main">Rolladen-Schneider LS4</span> Single seat German glider 1980

The Rolladen-Schneider LS4 is a Standard Class single seat glider manufactured by Rolladen-Schneider Flugzeugbau GmbH between 1980 and 2003.

<span class="mw-page-title-main">Schempp-Hirth Standard Cirrus</span> German single-seat glider, 1969

The Standard Cirrus is a German Standard-class glider built by Schempp-Hirth. The Standard Cirrus was produced between 1969 and 1985, when it was replaced by the Discus. Over 800 examples were built, making it one of the most successful early fibreglass glider designs.

The Schempp-Hirth HS-3 Nimbus was a prototype glider built by Klaus Holighaus.

<span class="mw-page-title-main">Schempp-Hirth Nimbus-2</span> German single-seat glider, 1971

The Schempp-Hirth Nimbus-2 is an Open Class glider built by Schempp-Hirth during the 1970s. The Nimbus-2 first flew in April 1971 and a total of over 240 examples of all subtypes have been built until the beginning of the 1980s. It replaced the Schempp-Hirth Cirrus.

<span class="mw-page-title-main">Schleicher ASW 15</span> German single-seat glider, 1968

The Schleicher ASW 15 is a single-seat sailplane designed in 1968 by Gerhard Waibel and manufactured by Alexander Schleicher GmbH & Co. The ASW 15 has shoulder-mounted wings and an all-flying tailplane, with its single tow-release placement a compromise between winching and aerotowing. The later ASW 15B had several improvements, including a tow-release placed on the plane of symmetry, an 11 cm taller rudder, a slightly larger main wheel, and the provision of a 90-litre water ballast system.

<span class="mw-page-title-main">Schneider ES-65</span> Type of aircraft

The Schneider ES-65 Platypus is a two-seater unflapped glider designed and built by Edmund Schneider Pty in Australia. A single prototype was built, which remains operational as of 2012.

<span class="mw-page-title-main">Schleicher ASK 23</span> German glider, 1983

The Schleicher ASK 23 is a single-seat Club Class sailplane that was built by the German manufacturer Alexander Schleicher GmbH & Co.

The Sigma is an experimental glider developed in Britain from 1966 by a team led by Nicholas Goodhart. After disappointing performance during flight testing the Sigma was passed on to a Canadian group which carried out modifications, making the Sigma more competitive.

<span class="mw-page-title-main">SZD-38 Jantar 1</span> Polish single-seat glider, 1972

The SZD-38 Jantar 1 (Amber) is a glider designed and produced in Poland from 1971.

<span class="mw-page-title-main">SZD-41 Jantar Standard</span> Type of aircraft

The SZD-41 Jantar Standard was a Standard Class glider designed and produced in Poland from 1973.

<span class="mw-page-title-main">SZD-48 Jantar Standard 2/3</span> Polish single-seat glider, 1977

The SZD-48 Jantar Standard 2 is a Standard Class glider that was designed and produced in Poland starting in 1977.

The Applebay GA-111 Mescalero is an American high-wing, T-tailed single-seat, FAI Open Class glider that was designed by George Applebay.

The Akaflieg Darmstadt D-40 is an experimental variable geometry single seat sailplane, fitted with almost full span, camber changing flaps for optimum aerodynamics in weak thermals and integrated into the wing so as to minimise flap tip drag. One flew successfully but the D-40, like other variable geometry sailplanes, was not commercialised.

The Akaflieg Braunschweig SB-11 is an experimental, single seat, variable geometry sailplane designed by aeronautical students in Germany. It won the 15 m span class at the World Gliding Championships of 1978 but its advances over the best, more conventional, opposition were not sufficient to lead to widespread imitation.

The Akaflieg Braunschweig SB-7 Nimbus is a Standard class glider designed and built in Germany in the 1960s. It was one of a series of mixed glass fibre and wood designs from the students of Akaflieg Braunschweig.

The Akaflieg Braunschweig SB-8 is an experimental, single-seat, high performance glider built in Germany in the 1960s, constructed largely from glass fibre skin over built up balsa wood structure. Two were built; the second of which was later fitted with a high aspect ratio (30:1) wing, becoming the Akaflieg Braunschweig SB-9 Stratus.

<span class="mw-page-title-main">SZD-42 Jantar 2</span> Type of aircraft

The SZD-42 Jantar 2 is a single seat Open Class competition glider, designed and produced in Poland in the 1970s. It features a span of over 20 m (66 ft) and elastic, camber changing flaps. It was placed second, third and seventh at the 1976 World Gliding Championships. Over one hundred were built and more than ninety remain registered.

<span class="mw-page-title-main">Ciani Urendo</span> Type of aircraft

The Ciani EC 38/56 Urendo, or SSVV EC 38/56 Urendo is an Italian tandem-seat training glider from the 1950s. Four were built, one winning the Italian National Championships in 1959. Another, restored, still flies.

References

  1. 1 2 3 4 5 6 7 Simons, Martin. Sailplanes 1965-2000. 2nd revised edition. EQIP Werbung und Verlag G.m.b.H.. Königswinter. 2005. ISBN   3-9808838-1-7
  2. Kauh, Elaine (June 26, 2015). "Soaring Pioneer George Applebay Dies At 89". AVweb. Retrieved June 29, 2015.
  3. 1 2 3 Applebay Zuni II, National Air and Space Museum. Accessed 2010-11-05.
  4. Applebay Zuni II. Aviation History Online Museum. Accessed 2010-11-05.
  5. Kōzō Kawata, Takashi Akasaka. Composite materials mechanics, mechanical properties and fabrication.
  6. "Region 10 South Final Summary, Official" . Retrieved April 5, 2011.
  7. Federal Aviation Administration (10 March 2015), Make / Model Inquiry Results, accessed 10 March 2015.
  8. National Air and Space Museum (n.d.). "Applebay Zuni II" . Retrieved May 28, 2011.
  9. Zuni Applebay Archived March 22, 2012, at the Wayback Machine , SailplaneDirectory.com. Accessed 2010-11-05.