Facetmobile

The Facetmobile (properly, FMX-4 Facetmobile) is a homebuilt aircraft designed by Barnaby Wainfan, a well known professional aerodynamicist and homebuilt aircraft expert.

While only one Facetmobile prototype was produced, it has become well known due to its unique nature. The aircraft is somewhat of a cross between a lifting body and flying wing configuration - the whole aircraft is one low aspect ratio wing: a flat, angular lifting shape. Particularly notable is that the aircraft's shape is formed of a series of 11 flat surfaces, somewhat similar to the body of the F-117 Nighthawk jet strike aircraft, but without separate wing structures. The Facetmobile was designed prior to the public disclosure of the F-117 aircraft shape, and Wainfan claims that the visual similarity is coincidental, with very different engineering reasons (the F-117 uses flat panels for stealth technology, the Facetmobile for ease of construction). [http://members.aol.com/slicklynne/facet.htm Barnaby and Lynn Wainfan's Facetmobile page] , accessed Oct 24, 2006]

Design

The Facetmobile is a unique design in many ways. [http://members.aol.com/slicklynne/fmfaq.htm Facetmobile FAQ] , accessed Oct 24, 2006]

hape

As noted above, the Facetmobile is a unique airfoil shape, but is generally similar to some other generally low aspect ratio delta wing light aircraft, such as the Dyke Delta models JD1 and JD2, the Hatfield LB1 and LB3, and the ARUP 2.

The FMX-4 Facetmobile shape forms 11 flat planes, plus two wingtip rudders. Three flat shapes form the bottom of the aircraft (slightly inclined front, flat middle, and sharply raised back), and eight form the top (one large downwards sloping rear section, one thin nose section, and three inclined side panels per side). The wing section is an 18% thickness ratio, much thicker than the typical 12-15% thickness of normal light aircraft wings.

tructure

The facetmobile structure is 6061 aluminum round tubes, joined together by rivetted gussets, and covered in a fabric covering.

pecifications

aircraft specification

plane or copter?=plane
jet or prop?=prop
crew=1
length main= 19 ft 6 in
length alt=5.95 m
span main= 15 ft
span alt=4.57 m
area main=214 ft²
area alt=19.9 m²
empty weight main= 370 lb
empty weight alt= 168 kg
loaded weight main= 740 lb
loaded weight alt= 336 kg
max takeoff weight main=
max takeoff weight alt=
engine (prop)=Rotax 503 DC
type of prop=Fixed
number of props=1
power main= 46 hp
power alt= 34 kw
max speed main=96 knots
cruise speed main= 80 knots
stall speed main= 33 knots
climb rate main= 750 ft/min
loading main= 3.45 lb/sq ft

Media coverage

Media coverage for the Facetmobile design and related concepts has been extensive. Coverage includes:
* Life on the Facet Track, Kitplanes magazine, February 1995. Reprinted online at [http://members.aol.com/slicklynne/kitpl1.htm]
* Other print coverage includes articles in:
** KITPLANES: 9/93
** KITPLANES: 2/95 (above)
** KITPLANES: 3/95
** Sport Aviation: 10/94
** Experimenter: 10/94
** Air Progress: 1/95
** Air Progress: 2/95
** Flying: 10/94
** Pacific Flyer: 2/94
** Model Builder: 10/96
** Flight (Air Age): Nov/Dec 1996
** Volare Sport (Italy): 10/94
** Aero Revue (Switzerland): 6/95
** Aircraft Illustrated (UK) 5/95
** Contact Issue #71
** Popular Science: January 2005

Current status

The prototype FMX-4 Facetmobile crashed on October 13, 1995, after an in-flight engine failure. The aircraft landed at low speed into a barbed wire fence which caused extensive skin, engine, and some structural damage, though there was no injury to the pilot (Barnaby Wainfan). As of 2006, the aircraft has been partially repaired but not flown again.

Derivatives

Wainfan has proposed two derivative aircraft based on the FMX-4 Facetmobile.
* FMX-5 Facetmobile, a larger 2-seat design using the same aluminum tube and fabic construction.
* An unnamed similar 2-seat design using advanced flat composite panel construction. [http://members.aol.com/slicklynne/pavreport.pdf NASA LARC NAG-1-03054 "Feasibility Study of the Low Aspect Ratio All All-Lifting Configuration as a Low-Cost Personal Aircraft"] , Barnaby Wainfan and Hans Neiubert, February 2004, accessed Oct 24, 2006]

Models

At least one commercial model airplane kit of the Facetmobile is in production. [ [http://www.eam.net/EAMRC/skunkworks/Facetmobile/incredible_facetmobile.htm Incredible Facetmobile] , accessed Oct 24, 2006]

References

External links

* [http://members.aol.com/slicklynne/facet.htm Barnaby and Lynne Wainfan's Facetmobile page] , accessed Oct 24, 2006. Also available at [http://www.facetmobile.com www.facetmobile.com]