US Aviation Cumulus

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Cumulus
Role Motor glider
National origin United States
Manufacturer US Aviation
Designer Dave Ekstrom
First flight 1995
Introduction 1995
Status Production completed
Number built 5 (Dec 2011)[1]
Unit cost
US$7,995 (without engine or instruments, 2011)
Developed from US Aviation Cloud Dancer

The US Aviation Cumulus is an American low-wing, single-seat, open cockpit motor glider that was designed by Dave Ekstrom and produced by US Aviation, supplied in kit form for amateur construction.[1][2][3][4][5][6]

Design and development[edit]

The Cumulus was conceived as a lightweight motorglider for soaring and also for touring. It is a development of the earlier US Aviation Cloud Dancer design. The aircraft production was outsourced, initially produced by AeroDreams it was later produced by Dave Ekstrom for US Aviation after 2004. The Cumulus first flew in 1995 and was named after the cumulus cloud.[2][5][6]

Built from steel tubing, composites and fabric, the Cumulus is powered by a standard Rotax 447 40 hp (30 kW) engine in pusher configuration, although engines from 20 to 55 hp (15 to 41 kW) can be fitted. The wings are detachable for transport or storage. It has a glide ratio of 20:1. The landing gear is conventional and the cruciform tail is strut-braced.[2][3][4][5]

Construction time from the kit is estimated at 200 hours.[4]

Specifications (Cumulus)[edit]

Data from Purdy and KitPlanes[3][4][5]

General characteristics

  • Length: 20 ft 0 in (6.10 m)
  • Wingspan: 43 ft 0 in (13.11 m)
  • Height: 4 ft 6 in (1.37 m)
  • Wing area: 141 sq ft (13.1 m2)
  • Aspect ratio: 13:1
  • Empty weight: 320 lb (145 kg)
  • Gross weight: 560 lb (254 kg)
  • Fuel capacity: 5 U.S. gallons (19 L; 4.2 imp gal)
  • Powerplant: 1 × Rotax 447 twin cylinder, two-stroke iarcraft engine, 40 hp (30 kW)

Performance

  • Maximum speed: 85 mph (137 km/h; 74 kn)
  • Cruise speed: 75 mph (121 km/h; 65 kn)
  • Stall speed: 32 mph (51 km/h; 28 kn) in landing configuration
  • Never exceed speed: 89 mph; 78 kn (144 km/h)
  • Range: 275 mi (239 nmi; 443 km)
  • Service ceiling: 15,000 ft (4,600 m)
  • Maximum glide ratio: 20:1 at 34 mph (55 km/h)
  • Rate of climb: 800 ft/min (4.1 m/s)
  • Rate of sink: 195 ft/min (0.99 m/s) at 43 mph (69 km/h)

See also[edit]

Aircraft of comparable role, configuration and era

References[edit]

  1. ^ a b Vandermeullen, Richard: 2011 Kit Aircraft Buyer's Guide, Kitplanes, Volume 28, Number 12, December 2011, page 73. Belvoir Publications. ISSN 0891-1851
  2. ^ a b c Bertrand, Noel; Rene Coulon; et al: World Directory of Leisure Aviation 2003-04, page 59. Pagefast Ltd, Lancaster OK, 2003. ISSN 1368-485X
  3. ^ a b c Purdy, Don: AeroCrafter - Homebuilt Aircraft Sourcebook, page 314. BAI Communications. ISBN 0-9636409-4-1
  4. ^ a b c d Downey, Julia: 2008 Kit Aircraft Directory, Kitplanes, Volume 24, Number 12, December 2007, page 77. Primedia Publications. ISSN 0891-1851
  5. ^ a b c d Downey, Julia: 1999 Kit Aircraft Directory, Kitplanes, Volume 15, Number 12, December 1998, page 74. Primedia Publications. ISSN 0891-1851
  6. ^ a b Bayerl, Robby; Martin Berkemeier; et al: World Directory of Leisure Aviation 2011-12, page 138. WDLA UK, Lancaster UK, 2011. ISSN 1368-485X

External links[edit]