The Nimbus series was designed as an attempt to combine a high aspect ratio wing with a thin airfoil section to produce a fast cross country sailplane.[1][2]
The first Nimbus prototype used a Göttingen airfoil, which resulted in lower than expected performance. It first flew in 1954.[3] The Nimbus III, introduced in 1956, employed an FX-05-191 airfoil and this greatly improved performance. The Nimbus III is constructed entirely from wood and incorporates a three-piece wing, with a center section and removable wing tips. Rib spacing is 6 inches and the plywood leading edge extends to 83% of the chord.[1][2][4]
Operational historyedit
The original Nimbus's fuselage was severely damaged at the May 1954 NCSA Soaring Meet during a cross country flight and as a result the Nimbus II was rushed to completion to be ready for the US National Soaring Contest in 1954 at Lake Elsinore, California. The Nimbus II was completed in time and Dr. J.B. Sawyer flew it to 15th place. He was forced to withdraw from the contest after the 5th day when he let go of the controls in flight and the glider pitched up steeply. After landing it was discovered that the elevator attach bracket was bent and they were unable to repair it at the contest. Sawyer went on to fly the Nimbus II on a 230-mile flight at a 1955 glider meet in Lincoln, California. He also soared it to over 20,000 ft (6,096 m) in Minden, Nevada during the summer of 1955. At the 1956 US National Contest in Grand Prairie, Texas the Nimbus III was flown by Vic Swierkowski and won the Design Contest. The Nimbus II was also flown at the Nationals by Sawyer in 1956 and actually out-scored the Nimbus III.[1][2][4][5][6]
Nine Nimbus III kits were produced by Mitchell and of these, four were reported as having been completed. In April 2011 there was one Nimbus III on the US Federal Aviation Administration registry.[1][2][7]
^National Soaring Museum (2011). . Archived from the original on May 16, 2011. Retrieved February 26, 2011.
February 25, 2024
mitchell, nimbus, series, american, single, seat, high, wing, gliders, that, designed, mitchell, 1950s, mitchell, also, well, known, ultralight, mitchell, wing, designs, nimbusrole, glidernational, origin, united, statesdesigner, mitchellfirst, flight, 1954int. The Mitchell Nimbus is a series of American single seat high wing gliders that was designed by Don Mitchell in the 1950s Mitchell is also well known for his ultralight Mitchell Wing A 10 and U 2 designs 1 2 NimbusRole GliderNational origin United StatesDesigner Don MitchellFirst flight 1954Introduction 1956 Nimbus III Status Production complete Contents 1 Design and development 2 Operational history 3 Variants 4 Aircraft on display 5 Specifications Nimbus III 6 See also 7 ReferencesDesign and development editThe Nimbus series was designed as an attempt to combine a high aspect ratio wing with a thin airfoil section to produce a fast cross country sailplane 1 2 The first Nimbus prototype used a Gottingen airfoil which resulted in lower than expected performance It first flew in 1954 3 The Nimbus III introduced in 1956 employed an FX 05 191 airfoil and this greatly improved performance The Nimbus III is constructed entirely from wood and incorporates a three piece wing with a center section and removable wing tips Rib spacing is 6 inches and the plywood leading edge extends to 83 of the chord 1 2 4 Operational history editThe original Nimbus s fuselage was severely damaged at the May 1954 NCSA Soaring Meet during a cross country flight and as a result the Nimbus II was rushed to completion to be ready for the US National Soaring Contest in 1954 at Lake Elsinore California The Nimbus II was completed in time and Dr J B Sawyer flew it to 15th place He was forced to withdraw from the contest after the 5th day when he let go of the controls in flight and the glider pitched up steeply After landing it was discovered that the elevator attach bracket was bent and they were unable to repair it at the contest Sawyer went on to fly the Nimbus II on a 230 mile flight at a 1955 glider meet in Lincoln California He also soared it to over 20 000 ft 6 096 m in Minden Nevada during the summer of 1955 At the 1956 US National Contest in Grand Prairie Texas the Nimbus III was flown by Vic Swierkowski and won the Design Contest The Nimbus II was also flown at the Nationals by Sawyer in 1956 and actually out scored the Nimbus III 1 2 4 5 6 Nine Nimbus III kits were produced by Mitchell and of these four were reported as having been completed In April 2011 there was one Nimbus III on the US Federal Aviation Administration registry 1 2 7 Variants editNimbus I Initial version with a Gottingen airfoil 1 2 Nimbus II Improved version 1 2 Nimbus III Improved version with an FX 05 191 airfoil 1 2 Aircraft on display editNational Soaring Museum Nimbus III 8 Specifications Nimbus III editData from Sailplane Directory and Soaring 1 2 General characteristicsCrew one Wingspan 40 ft 0 in 12 19 m Wing area 106 sq ft 9 8 m2 Aspect ratio 14 7 1 Airfoil FX 05 191 Empty weight 450 lb 204 kg Gross weight 670 lb 304 kg Performance Maximum glide ratio 39 1 at 66 mph 106 km h Rate of sink 144 ft min 0 73 m s at 44 mph 71 km h Wing loading 6 4 lb sq ft 31 kg m2 See also editList of glidersReferences edit a b c d e f g h i Activate Media 2006 Nimbus III Mitchell Archived from the original on April 5 2012 Retrieved April 4 2011 a b c d e f g h i Said Bob 1983 Sailplane Directory Soaring Magazine page 15 Soaring Society of America November 1983 USPS 499 920 J2mcL Planeurs Fiche planeur n www j2mcl planeurs net Retrieved May 20 2022 a b Swierkowski Vic May June 1956 Nimbus III Soaring 20 3 17 19 21st National Story Soaring 18 5 5 September October 1954 Barnaby Captain R S September October 1956 23rd Annual US National Soaring Championships Soaring 20 5 13 19 Federal Aviation Administration April 2011 Make Model Inquiry Results Retrieved April 18 2011 National Soaring Museum 2011 Sailplanes in Our Collection Archived from the original on May 16 2011 Retrieved February 26 2011 Retrieved from https en wikipedia org w index php title Mitchell Nimbus amp oldid 1088932547, wikipedia, wiki, book, books, library,
