GEFA-Flug

GEFA-Flug GmbH (Gesellschaft zur Entwicklung und Förderung aerostatischer Flugsysteme) was a German company based in Aachen that manufactured hot-air balloons and hot-air airships. Founded in 1980, it was approved by the German Federal Aviation Office (Luftfahrt-Bundesamt, LBA) as a development, manufacturing, and aviation engineering operation under JAR 21, and it also carried out maintenance and repair work on types approved by the UK Civil Aviation Authority (CAA). Beyond designing and selling aircraft, GEFA-Flug was involved in the design and decoration of balloons and airships for banner advertising, advertising deployments, and promotional tours, as well as pilot training. The company also conducted passenger flights with its aircraft. GEFA-Flug worked on airship systems from the mid-1970s and on hot-air airships from the early 1980s. Its early years focused on remote-controlled systems; experience gained there fed into the development of manned hot-air airships from 1985, operated in cooperation with Thunder & Colt under the name "The Airship Alliance." Later cooperation with Cameron Balloons, which acquired Thunder & Colt in 1995, led to a first two-seat prototype approved by the German LBA in 1990. The design featured greater hull elongation than English types, improving appearance and maneuverability. Two burners mounted in a V-shape and directed forward and backward, combined with fabric bulkheads dividing the hull, allowed active trim control similar to ballonets in gas airships. This trim, a slimmer shape, and higher internal pressure, together with improved aerodynamics, significantly increased flight speed. The volume was 2,250 m³, powered by a 38 kW (52 hp) Rotax engine, with a flight time of about one hour as a two-seater. Two AS 80 GD airships were approved as single units by the German LBA. Hulls were made in Germany, two-seat gondolas in the UK, and four-seat gondolas at GEFA-Flug in Aachen. The four-seat version was approved by the LBA at the end of 1999. Marketing was handled jointly by both firms. By October 2012, in addition to the two AS 80 GD airships, 62 AS 105 GD airships had been built. A larger airship type with room for six passengers (pilot + 5) and a volume of 5,000 m³ was developed, scaling up the four-seat hull shape but changing the tailplane angle so that the horizontal stabilizers hang slightly, improving landing in strong headwinds on small fields. A night-flight lighting system and a "whisper burner" allowed operation between sunset and sunrise and produced effective advertising illumination. GEFA-Flug also developed and built special hot-air balloons and airships for ecological research and documentation of environmental damage. Projects included multi-month deployments for photogrammetric documentation of Mohenjo-Daro, a 5,000-year-old ruined city in Pakistan, with similar projects in Oman, Greece, Turkey, Syria, Israel, the former Yugoslavia, Egypt, France, Switzerland, Spain, and England. Research areas included monitoring of contaminated sites, spoil tips, nature reserves, and water bodies; climate studies of near-ground air layers; land-use surveys and erosion monitoring; inspection of quarries, material heaps, and settling basins; documentation of architectural monuments; and aerial photography for reconstructing archaeological sites. The AS 105 GD airship type was approved by the UK CAA as a two-seat version (using a CAA-approved gondola type from Thunder & Colt) in spring 1996 and was also approved for night flights from 2001. Its length overall was 41.0 m, diameter 12.8 m, volume 3,000 m³, powered by a Rotax two-stroke gasoline engine of 48 kW (65 hp) with a four-blade CFRP propeller, maximum takeoff weight 900 kg, flight duration up to 3 hours single-seat, 2 hours two-seat, 1 hour four-seat, maximum speed 40 km/h, crew and passengers pilot plus 1, and from autumn 1999 also pilot plus 3.

GEFA-Flug GmbH (Gesellschaft zur Entwicklung und Förderung aerostatischer Flugsysteme) was a German company based in Aachen that manufactured hot-air balloons and hot-air airships. It was founded in 1980 and was approved by the German Federal Aviation Office (Luftfahrt-Bundesamt, LBA) as a development, manufacturing, and aviation engineering operation under JAR 21. It also carried out maintenance and repair work on types approved by the UK Civil Aviation Authority (CAA). In addition to planning and selling aircraft, the company was involved in the design and decoration of balloons and airships for banner advertising, advertising deployments, and promotional tours, as well as pilot training. It also conducted passenger flights with its aircraft. The company worked on airship systems from the mid-1970s and on hot-air airships from the early 1980s. In the early years the focus was on remote-controlled systems. Experience gained there fed into the further development of manned hot-air airships from 1985, operated in cooperation with Thunder & Colt under the name "The Airship Alliance." Within this cooperation concept—later also with Cameron Balloons, which acquired Thunder & Colt in 1995—a first two-seat prototype approved by the German LBA was created in 1990. This prototype had greater hull elongation than the English types, which significantly improved not only its appearance but also its general maneuverability. By using the two burners—now mounted in a V-shape opposite each other and directed forward and backward—in combination with several fabric bulkheads dividing the hull into different parts similar to the gas cells of rigid airships, the trim behavior could be actively influenced. The system is thus comparable to trimming via ballonets in gas airships. This trim, a slimmer shape, and increased internal pressure, together with improved aerodynamics, led to a significantly higher flight speed. The volume was 2,250 m³, propulsion was a 38 kW (52 hp) Rotax engine, and flight time as a two-seater was about one hour. Two AS 80 GD airships were approved as single units by the German LBA. The hulls were manufactured in Germany, the two-seat gondolas were made in the UK, and the four-seat gondolas were built at GEFA-Flug in Aachen. The four-seat version was approved by the German LBA at the end of 1999. Marketing was carried out jointly by both companies. By October 2012, in addition to the two AS 80 GD airships mentioned above, 62 AS 105 GD airships had been built. A larger airship type with room for 6 passengers (pilot + 5) and a volume of 5,000 m³ was developed, adopting the basic hull shape of the four-seat airship and scaling it up to 5,000 m³. The angle of attack of the tailplanes was changed: the horizontal stabilizers no longer lie completely horizontal but hang slightly, because with a sinking ship and strong engine thrust the nose points down rather than up. This is related to the lower air resistance of the tailplanes in the vertical when the ship sinks. This made it easier to land in strong headwinds on small fields. Another innovation was night-flight lighting that allowed the airship to be operated between sunset and sunrise. In combination with the so-called whisper burner, this produced very good illumination of the airship hull, which is very effective for advertising against the night sky. GEFA-Flug also developed and built special hot-air balloons and airships that served ecological research and the documentation of environmental damage. Projects included multi-month deployments for photogrammetric documentation of Mohenjo-Daro, a 5,000-year-old ruined city in Pakistan. Similar projects were undertaken in Oman, Greece, Turkey, Syria, Israel, the former Yugoslavia, Egypt, France, Switzerland, Spain, and England. Research areas included: monitoring of contaminated sites, spoil tips, nature reserves, and water bodies; climate studies of near-ground air layers; land-use surveys and erosion monitoring; inspection of quarries, material heaps, and settling basins; documentation of architectural monuments; and aerial photography for reconstructing archaeological sites. The AS 105 GD airship type had already been approved by the English aviation authority CAA as a type in spring 1996 as a two-seat version (using a CAA-approved gondola type from Thunder & Colt). In addition, it had been approved for night flights since 2001. Its length overall was 41.0 m, diameter 12.8 m, volume 3,000 m³, propulsion a Rotax two-stroke gasoline engine with 48 kW (65 hp) and a four-blade CFRP propeller, maximum takeoff weight 900 kg, flight duration up to 3 h single-seat, 2 h two-seat, 1 h four-seat, maximum speed 40 km/h, crew and passengers pilot plus 1, and from autumn 1999 also pilot plus 3. In 2005 the company began another project, the development of the six-seat airship AS 105 GD/6. In 2015 the company had to enter liquidation proceedings, which concluded in 2017 with the dissolution of the German company. The GEFA-Flug type certificates were sold to the company Impacto Aereo in Mexico, as a result of which production of GEFA-Flug airships could be continued in Mexico City.

• 2017

  Dissolution of the German company completed; type certificates sold to Impacto Aereo in Mexico.

• 2015

  Company entered liquidation proceedings.

• 2012

  By October, 62 AS 105 GD airships had been built (plus two AS 80 GD).

• 2005

  Development began on six-seat airship AS 105 GD/6.

• 2001

  AS 105 GD approved for night flights.

• 1999

  Four-seat version approved by German LBA at end of year; AS 105 GD approved for pilot plus 3 from autumn.

• 1996

  AS 105 GD airship type approved by UK CAA as two-seat version.

• 1995

  Cameron Balloons acquired Thunder & Colt; cooperation continued.

• 1990

  First two-seat prototype approved by the German LBA.

• 1985

  Experience from remote-controlled systems fed into development of manned hot-air airships in cooperation with Thunder & Colt as "The Airship Alliance."

• 1980

  GEFA-Flug GmbH founded in Aachen, Germany.

Specialist developer and manufacturer of hot-air balloons and hot-air airships, including advertising and research platforms, approved under JAR 21 by the German LBA.

• AS 80 GD

  Two-seat hot-air airship, volume 2,250 m³, 38 kW (52 hp) Rotax engine, about one hour flight time; two units approved as single pieces by German LBA.

• AS 105 GD

  Hot-air airship, length 41.0 m, diameter 12.8 m, volume 3,000 m³, 48 kW (65 hp) Rotax engine, max takeoff weight 900 kg, max speed 40 km/h; two-seat version approved by UK CAA in 1996, four-seat by German LBA in 1999; 62 built by October 2012.

• AS 105 GD/6

  Six-seat hot-air airship (pilot + 5), volume 5,000 m³, development began in 2005; features modified tailplane angle and night-flight lighting.

1. 1GEFA-Flugwikidata.org
2. 2GEFA-Flugde.wikipedia.org