FFA Diamant: The Pioneering All-Fiberglass Sailplane
The FFA Diamant, a family of Swiss high-wing, T-tailed, single-seat gliders, marked a milestone in aviation as the first sailplanes constructed entirely from fiberglass, without balsa or plywood sandwich materials. Designed by engineering students at ETH Zurich under Professor Rauscher and manufactured by Flug- und Fahrzeugwerke Altenrhein AG (FFA), the Diamant series—comprising the HBV, 16.5, and 18 models—debuted in 1964. Known for its sleek design and competitive performance, it excelled in FAI Standard and Open Class gliding, notably placing third and fourth in the 1968 World Gliding Championships. Our museum proudly displays a Diamant 16.5, showcasing its innovative engineering and historical significance.
History
After World War II, FFA, formerly part of Dornier Flugzeugwerke, sought new ventures as an independent Swiss company. The Diamant project began at ETH Zurich, with a prototype (Ka-Bi-Vo) flown in 1962 using Schleicher Ka 6 wings. Production models adopted Glasflügel H-301 Libelle wings for the HBV Diamant, which first flew on September 5, 1964. Only 13 HBV models were built before the Diamant 16.5, the first all-fiberglass sailplane, was introduced in 1967, with 43 produced. The Diamant 18, launched in 1968, extended the wingspan to 18 m, with five built. Early 16.5 and 18 models faced structural flutter issues at high speeds, which FFA resolved. The Diamant 18 saw experimental modifications, including a jet-powered version (Prometheus 1) by Entwicklungsgemeinschaft für Flugzeugbau (EFF) in 1971 and a 19 m wingspan upgrade by Dan Pierson in the U.S. By 2011, five HBV, 20 Diamant 16.5, and five Diamant 18 models remained registered in the U.S., reflecting their enduring appeal.
Design Features
The Diamant series features a high-wing, T-tailed, monocoque fuselage made entirely of epoxy-glassfiber with foam inserts, a departure from composite gliders using wood. The HBV used 15 m Glasflügel H-301 wings, while the 16.5 and 18 had FFA-designed wings with Wortmann FX 62-K-153m airfoils. A retractable monowheel landing gear and water ballast (320 lb in the 18) enhance performance. The all-moving tailplane, mounted atop the fin, and flapped wings with drooped ailerons improve thermalling. The Diamant’s sleek, reclined cockpit and aerodynamic design minimize drag, though FAA certification for the HBV and 16.5 mandates white paint to protect fiberglass from sunlight, with light-colored registration numbers.
Specifications
| Specification | Diamant HBV | Diamant 16.5 | Diamant 18 |
|---|---|---|---|
| Manufacturer | FFA | FFA | FFA |
| First Flight | September 5, 1964 | 1967 | February 1968 |
| Crew | 1 | 1 | 1 |
| Wingspan | 49 ft 2 in (15 m) | 54 ft 1 in (16.5 m) | 59 ft 1 in (18 m) |
| Length | 24 ft 7 in (7.5 m) | 24 ft 7 in (7.5 m) | 24 ft 7 in (7.5 m) |
| Wing Area | 145 sq ft (13.5 m²) | 154 sq ft (14.3 m²) | 154 sq ft (14.3 m²) |
| Aspect Ratio | 20.5:1 | 22.7:1 | 22.7:1 |
| Empty Weight | 580 lb (263 kg) | 615 lb (279 kg) | 615 lb (279 kg) |
| Gross Weight | 860 lb (390 kg) | 970 lb (440 kg) | 970 lb (440 kg) |
| Max Glide Ratio | 40:1 at 56 mph (90 km/h) | 45:1 at 62 mph (100 km/h) | 45:1 at 62 mph (100 km/h) |
| Rate of Sink | 0.55 m/s (108 ft/min) at 47 mph (75 km/h) | 0.52 m/s (102 ft/min) at 45 mph (72 km/h) | 0.52 m/s (102 ft/min) at 45 mph (72 km/h) |
| Wing Loading | 5.9 lb/sq ft (29 kg/m²) | 6.3 lb/sq ft (31 kg/m²) | 6.3 lb/sq ft (31 kg/m²) |
Flight Characteristics
The Diamant series is renowned for its high performance and responsive handling. The HBV, designed for FAI Standard Class, offers a 40:1 glide ratio, while the 16.5 and 18, built for Open Class, achieve 45:1 at 62 mph (100 km/h). Their low sink rates (0.52–0.55 m/s) and flapped wings with drooped ailerons excel in thermalling, allowing tight circles in weak lift. The retractable monowheel and water ballast enable high-speed cross-country gliding, though early flutter issues in the 16.5 and 18 required careful speed management (VNE 155 mph/250 km/h). The T-tail and all-moving tailplane provide precise control, making the Diamant a favorite in competitions like the 1968 World Gliding Championships, where Diamant 18s placed third and fourth.
Museum Significance
Our Diamant 19, is currently being restored. When finished it represents a leap in glider design as the first all-fiberglass sailplane. Its competitive success and innovative construction highlight FFA’s engineering prowess and the contributions of ETH Zurich students. Displayed alongside other gliders, it illustrates the evolution of composite materials in aviation. Visitors can explore its sleek fuselage, T-tail, and compact cockpit, appreciating its role in advancing soaring technology and its legacy in gliding competitions.
Additional History of Flug- und Fahrzeugwerke Altenrhein AG (FFA)
Early Beginnings and Dornier Roots
Flug- und Fahrzeugwerke Altenrhein AG (FFA), based in Altenrhein, Switzerland, near Lake Constance, traces its origins to 1924 when Claude Dornier, a prominent German aircraft designer, established Dornier-Werke Altenrhein AG. This move was a strategic response to the Treaty of Versailles, which restricted aircraft production in Germany after World War I. Switzerland’s neutrality and proximity to Germany made Altenrhein an ideal location for Dornier to continue his work. The company initially focused on assembling Dornier aircraft, including the iconic Do X flying boat, a massive 12-engine airliner that captured global attention in the 1930s. During this period, Altenrhein served as a hub for Dornier’s innovative designs, leveraging Swiss engineering precision and a skilled workforce to produce high-quality aircraft components and assemblies.
Post-War Independence and Diversification
After World War II, Dornier-Werke Altenrhein faced challenges due to Germany’s defeat and the reconfiguration of the European aviation industry. In 1948, Claudio Caroni, a Swiss industrialist, took leadership of the company, severing ties with Dornier’s German operations to establish FFA as an independent entity. Renamed Flug- und Fahrzeugwerke Altenrhein AG in 1949, the company expanded beyond aviation to include railcars, boats, and industrial components, reflecting Switzerland’s need for diversified manufacturing. Under Caroni’s ownership from 1952, FFA became a symbol of Swiss ingenuity, balancing aviation innovation with economic resilience. The company produced licensed aircraft, such as the de Havilland Vampire jet fighter for the Swiss Air Force, and ventured into original designs, most notably the P-16 jet fighter. The P-16, designed in the 1950s, was a promising supersonic aircraft, but after two prototype crashes in 1955 and 1957, the Swiss government canceled the program, redirecting funds to the Mirage III. Despite this setback, the P-16’s advanced design influenced later aircraft and showcased FFA’s engineering ambition.
The Diamant Sailplane and Global Recognition
In the 1960s, FFA made a significant mark in aviation with the Diamant sailplane series, the world’s first all-fiberglass gliders, developed in collaboration with engineering students at ETH Zurich under Professor Rauscher. The Diamant HBV, 16.5, and 18 models, introduced starting in 1964, revolutionized glider construction by eliminating traditional balsa and plywood sandwich materials, offering superior strength and aerodynamics. The Diamant 16.5 and 18 competed successfully in the 1968 World Gliding Championships, placing third and fourth, respectively, earning FFA international acclaim. Though only 61 Diamants were built due to high production costs, their innovative use of composites set a precedent for modern sailplane design. This period also saw FFA license-build aircraft like the Pilatus PC-6 Porter, further solidifying its role in Swiss aviation.
Expansion into Trainers and International Partnerships
The 1970s marked a high point for FFA with the AS-202 Bravo, a two-seat aerobatic trainer designed by Sergio Stefanutti. First flown in 1969, the Bravo entered production in 1971, with over 160 units exported to countries like Morocco, Uganda, and Indonesia. Its success demonstrated FFA’s ability to produce versatile, cost-effective aircraft for global markets. Concurrently, FFA collaborated with William Lear on the SAAC-23 project, a precursor to the Learjet 23, contributing components to early business jets. This partnership highlighted Altenrhein’s growing expertise in precision manufacturing. Beyond aviation, FFA diversified into railcar production for the Rhätische Bahn and other Swiss railways, as well as boats and industrial equipment, leveraging its Altenrhein facility’s versatility to maintain economic stability.
Restructuring and Legacy
By the 1980s, FFA faced increasing competition and financial pressures. In 1987, the company was split, with its aviation division sold to Justus Dornier, grandson of Claude Dornier, under Dornier Flugzeugbau GmbH. In 1994, Gautschi AG acquired FFA’s aviation operations, shifting its focus to supplying components for aircraft like the F/A-18 Hornet, Airbus A320, and Dornier 328. The Altenrhein site transitioned into an industrial park, with aviation activities continued by successors like Altenrhein Aviation AG, which maintains and overhauls aircraft. The FFA Museum in Altenrhein preserves the company’s legacy, displaying artifacts like the Diamant sailplane and AS-202 Bravo components. FFA’s contributions to Swiss aviation, from the P-16’s ambition to the Diamant’s innovation and the Bravo’s global reach, underscore its enduring impact on aerospace engineering.