MIT BURD II
{{Short description|1970s United States human-powered aircraft}}
{{DISPLAYTITLE:MIT BURD II}}
{{Use mdy dates|date=April 2023}}
{{Use American English|date=April 2023}}
| {{Infobox aircraft begin
|name =MIT BURD II |image = |caption = }} {{Infobox aircraft type |type =Human-powered aircraft |national origin =United States |manufacturer =Massachusetts Institute of Technology |designer =Paul Hooper |first flight = |introduction = |retired = |status = |primary user = |more users = |produced = |number built =1 |program cost = |unit cost = |developed from =MIT BURD |variants with their own articles = }} |
The BURD II was a two-place human-powered biplane, designed and built by graduates and undergraduates of the Massachusetts Institute of Technology. It is very similar to the original BURD, which suffered a structural collapse during testing in 1975, but incorporated changes to its structure and its control systems.
Background
Construction of the BURD II began in June 1976 and was completed by September of that year. It differed from the original BURD in several ways. While the wing spars of the original craft were box-beams made from balsa, for the new airplane they were made from carbon fiber. The secondary structure, in addition to balsa, incorporated new materials, such as polystyrene, carbon fiber, and bamboo. The undercarriage's rear wheel was fitted with a shock-absorber. For the control system, changes made included the foreplane being held in a neutral position by bungee cords and, for yaw control, spoilers being fitted to the wingtip endplates, in addition to those located on the lower wing. Further changes included the fuselage having a full frontal fairing, and the central vertical fin, located above the upper wing, being redesigned so that it had a new profile.
Flight attempts with the BURD proved unsuccessful and, when the £50,000 Kremer prize was won in August 1977, interest in the project waned. In October 1978, four MIT undergraduates (all members of the MIT Rocket Society) were given access to the BURD II, with the intention of modifying the craft so that it could be made to fly. In November, two model aircraft engines, rated at 1.50 hp (1.1 kW), powering 12 in (30.5 cm) propellers, were fitted on either side of the fuselage. A series of taxiing trials, which continued through to late November, were conducted. On the last test, with Harold Youngren acting as pilot, and also pedalling, the BURD II reached takeoff speed, at which point the foreplane collapsed and the craft veered off course, causing further structural damage.
After that event, the aircraft was dismantled. Subsequent analysis by MIT graduate Bob Parks determined that the BURD design had fundamental deficiencies in its engineering, with its center of gravity being too far forward, and the wings' box-spars and wire trussing also being inadequate for the task.
Specifications
{{Aircraft specs|ref=Jane's all the world's aircraft 1976–77
|prime units?=imp
|crew=2
|capacity=
|length m=
|length ft=26
|length in=6
|span m=
|span ft=62
|span in=
|span note=
|upper span ft=
|upper span in=
|upper span note=
|mid span m=
|mid span ft=
|mid span in=
|mid span note=
|lower span m=
|lower span ft=
|lower span in=
|lower span note=
|swept m=
|swept ft=
|swept in=
|swept note=
|dia m=
|dia ft=
|dia in=
|dia note=
|width m=
|width ft=
|width in=
|width note=
|height m=
|height ft=13
|height in=4
|height note=
|wing area sqm=
|wing area sqft=640
|wing area note=plus 66 sq ft (6.13 m2) canard wing area
|swept area sqm=
|swept area sqft=
|swept area note=
|volume m3=
|volume ft3=
|volume note=
|aspect ratio=
|airfoil=Wortmann FX61-164
|empty weight kg=
|empty weight lb=126
|empty weight note=
|gross weight kg=
|gross weight lb=
|gross weight note=
|max takeoff weight kg=
|max takeoff weight lb=440
|max takeoff weight note=
|more general=
|eng1 number=2
|eng1 name=
|eng1 type=Cyclist pilot
|eng1 kw=
|eng1 hp=
|eng1 shp=
|eng1 kn=
|eng1 lbf=
|eng1 note=
|power original=
|thrust original=
|eng1 kn-ab=
|eng1 lbf-ab=
|max speed kmh=
|max speed mph=19
|max speed kts=
|max speed note=
|max speed mach=
|cruise speed kmh=
|cruise speed mph=17
|cruise speed kts=
|cruise speed note=
|stall speed kmh=
|stall speed mph=13.5
|stall speed kts=
|stall speed note=
|never exceed speed kmh=
|never exceed speed mph=20.5
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kmh=
|minimum control speed mph=
|minimum control speed kts=
|minimum control speed note=
|g limits=
|roll rate=
|glide ratio=
|sink rate ms=
|sink rate ftmin=
|sink rate note=
|lift to drag=
|wing loading kg/m2=
|wing loading lb/sqft=0.69
|wing loading note=
|prop blade number=2
|prop name=
|prop dia m=
|prop dia ft=10
|prop dia in=
|prop dia note=
}}
See also
{{aircontent
|see also=
|related=
|similar aircraft=
- Kohm Lady Godiva
- MacCready Gossamer Albatross
- MacCready Gossamer Condor
- MIT BURD
- MIT Chrysalis
- MIT Daedalus
|sequence=
|lists=
}}