Beck-Mahoney Sorceress

The Beck-Mahoney "Sorceress" was a racing staggerwing biplane originally designed by the father and son team of Lee and Seldon Mahoney with later improvements accomplished by pilot Don Beck. [ [http://www.aviation-history.com/garber/vg-bldg/beck_sorc-2_f.html Garber Center information] ]

The aircraft is famous as being the first biplane to exceed convert|200|mi/h|km/h|abbr=on on a race pylon course and also holds the distinction as being the most successful racing biplane in history. [http://www.airrace.com/New%20speed%20records.htm Records page from Society of Air Racing Historians] ] [http://www.airliners.net/open.file?id=0784449&size=M Image and information from Airliners.net] ] It was donated to the Smithsonian National Air and Space Museum after its last race, where it is currently housed in the Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Design

A reverse-stagger biplane, the Sorceress represents the state of the art at the time of its design, and remains one of the great design classics of air-racing within the United States.

Lee Mahoney, the designer, had experience in airframe construction with composite materials, metal-to-composite bonding technologies, and computational fluid dynamics. He applied his experience in Sorceress, and achieved success with several noteworthy design features, which include:
* Use of engine exhaust air flow to form a coanda-effect bonded laminar flow over the fuselage, which increases rudder efficiency by several orders of magnitude. Mahoney had originally designed the fuselage so that a fin would not be necessary - the fuselage would have ended with a rudder. His partners however preferred a more conventional treatment, but the Sorceress has one of the smallest conventional fins of any racing biplane to date.
*The aerofoil sections of the wings are designed as mirror image 'vanes' of symmetrical section - they interfere with each others flow in a manner which provides very high efficiency in turns, where as one vane-set/wing begins to lose efficiency, the other gains more, allowing for extremely high lift in turns with minimal loss of velocity
*Sorceress gains a great deal from composite bonding, with one of the first airframes to demonstrate almost perfect streamlining combined with very great strength. The wing enterplane struts are for show only - Sorceress could quite easily be flown without them, but racing rules require them.

Controversy

Sorceress was designed within the rules of the ARPA Biplane lass of 1965, and conformed with them without deviation. However, by 1972, successful competitors had a great deal of sway over the racing committee, and lobbyed successfully to have Sorceress banned from competition. Darrel Greenmayr was perhaps the competitor who had most to gain from Sorceress demise on the racing scene. Within the community, the treatment of the Sorceress team was considered scandalous by some, and justified by others, resulting in a number of setbacks for the team, culminating in retirement of the original team in 1973.

Items of contention included:
*The original configuration used a limited model of the Teledyne Continental O-360, a commonplace engine used. Nitpicking on the part of the technical team with regard to oil sump configuration saw massive changes effected on the airframe, almost resulting on loss of advantage with regard to coanda boundary layer. Nitpicking was also leveled at Mahoney for designing and implenting without sanction of an electronic ignition system, which gave the engine increased performance and reliability, which other competitors could not match for lack of design competency. This particular jealousy literally resulted in grounding for the Sorceress team.
*The undercarriage of the racer had to be modified to have a greater wheel diameter, faired, and be re-inforced by a significant degree. In fairness, the undercarriage had suffered collapse on several occasions in the aircraft's previous flights, and the ruling was considered justified by all, including the team, though with regret. With regard to the wheels, many competitors felt threatened by them. At the time of competition entry, wheel diameter as not specified in either statute or custom. Btplane competitors had never addressed this, and Sorceress' form and design were considered threatening enough. Wheel diameter proved utlitmately to be minor point - increase of diameter and width was easily accommodated within the design by producing a pant-fairing design of fibreglass which actually reduced induced drag to a greater degree than without fairings, negating any disadvantages that might otherwise be suffered.
*Wing length was originally equal span, producing a larger wing area than other competitors' machines had. Despite this, Sorceress was dramatically faster in both straight line and turns, thanks to innovative aerodynamics. She had minimal, non structural interplane struts, and this was another perceived threat to many competitors, whose machines relied on their interplane struts. The team was forced to reduce wing area, by sawing off a great deal of lower wing-plane outside of the struts. Swash plates also had to be installed. All these modifications were designed to slow Sorceress, but unfortunately for other competitors, the reduced wetted area only made Her faster !

Lee Mahoney took a lot of these accusations and comments personally, which is unsurprising given the vindictive behaviour of the Biplane racing community after the appearance of Sorceress, and spoke about his experiences to the magazine "Air Progress", which itself was outspoken at the time.

Notwithstanding the negative early experiences, Sorceress retains her claim to being the most technologically advanced biplane of any sort ever constructed, and her racing history subsequent to the controversy has gone on to proved the faith and skill of her designer, backers, and pilots.

Results and records

"Sorceress" placed in the following Reno Air Races, racing as #89: [http://www.airrace.org/raceResultsQueryDisplay.php Race results from the Reno Air Racing Association] ]

*1970: Biplane Consolation, 7th place, convert|152.380|mi/h|km/h|abbr=on, pilot: Lee Mahoney (crossed the finish line first, but automatically moved to last as it was racing as a fill-in).
*1971: Biplane Gold, 2nd place, convert|175.290|mi/h|km/h|abbr=on, pilot: Paul Deschamps
*1972: Biplane Gold, 1st place, convert|189.723|mi/h|km/h|abbr=on, pilot: Don Beck
*1973: Biplane Gold, 2nd place, convert|184.620|mi/h|km/h|abbr=on, pilot: Don Beck
*1974: Biplane Gold, 2nd place, convert|191.530|mi/h|km/h|abbr=on, pilot: Don Beck
*1975: Biplane Gold, 1st place, convert|198.990|mi/h|km/h|abbr=on, pilot: Don Beck
*1976: Biplane Gold, 1st place, convert|202.153|mi/h|km/h|abbr=on, pilot: Don Beck
*1980: Biplane Gold, 8th place, convert|210.730|mi/h|km/h|abbr=on, pilot: Don Beck (crossed finish first, disqualified for illegal passing)
*1982: Biplane Gold, 3rd place, convert|206.290|mi/h|km/h|abbr=on, pilot: Don Beck
*1983: Biplane Gold, 2nd place, convert|202.350|mi/h|km/h|abbr=on, pilot: Don Beck

"Sorceress" set a number of speed records in the Sport Biplane Class, including:
*190.48 mph, qualifying heat record, 1970 Reno Air Races
*189.723 mph, championship race record, 1972 Reno Air Races
*202.153 mph, championship race record, 1976 Reno Air Races

References

External links

* [http://www.nasm.si.edu/research/aero/aircraft/mahoney.htm Beck-Mahoney "Sorceress" Specifications from the Smithsonian National Air and Space Museum official website]