Hall Ibex

Hall Ibex
Role	Experimental glider
National origin	United States
Manufacturer	Stan Hall
Designer	Stan Hall
First flight	1968
Status	In storage
Primary user	Stan Hall
Number built	1

The Hall Ibex is an experimental, American, gull winged, single seat glider that was designed by Stan Hall and first flown in 1968.^[1]^[2]

Design & Development

The Ibex was designed by Hall to investigate the reduced wetted area of the pod and boom configuration, hands off spiral stability of a gull wing, and the low speed performance of wide NACA slotted flaps. It also features a V tail, 135 lb (61 kg) of water ballast and a 15 m (49.2 ft) wingspan to comply with FAI Standard Class rules.^[3] On one of its first flights the Ibex showed significant tail flutter. Initially Hall considered replacing the tail with a conventional empennage and tail^[4] but ended up moving the ruddervator counterweights from the tips to the roots which eliminated the problem.^[5]

Operational history

The Ibex was still flying in 1980 and was eventually donated to the National Soaring Museum.^[6]

Aircraft on display

National Soaring Museum - 1 in storage^[6]

Specifications (Hall Ibex)

Data from Sailplane Directory^[3]

General characteristics

Crew: one
Wingspan: 49 ft 0 in (15 m)
Wing area: 125 sq ft (11.6 m²)
Aspect ratio: 19.2
Airfoil: FX61-163 Root, 60-126 Tip
Empty weight: 580 lb (263 kg)
Gross weight: 905 lb (411 kg) 135 lbs of Water Ballast

Performance

Maximum glide ratio: 34:1
Lift-to-drag: 34
Wing loading: 7.25 lb/sq ft (35.4 kg/m²)

References

^ ^a ^b Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 43. Soaring Society of America, November 1983. USPS 499-920
^ Federal Aviation Administration (May 2011). "Make / Model Inquiry Results". Retrieved May 10, 2011.^{[permanent dead link]}
^ ^a ^b SSA. "Sailplane Directory". Archived from the original on April 13, 2011. Retrieved March 31, 2011.
^ Soaring, November 1967
^ Soaring, October 1974
^ ^a ^b National Soaring Museum (2011). "Sailplanes in Our Collection". Archived from the original on May 16, 2011. Retrieved February 26, 2011.