После окончания Первой мировой войны компания построила легкий самолет Butterfly, так и оставшийся в единственном экземпляре.
Flight, April 1920
L.W.F. Engineering Co. - The " Butterfly" is a one-man sport-model monoplane designed by J. L. Cato, and similar to the Cato Parasol described in FLIGHT for October 9, 1919.
It has a factor of safety of 12, a true monocoque fuselage and a loading of 10 lbs. per horse-power. The simplicity striven for is attained in its interchangeability of rudder and elevator, aileron, landing struts, wing supports and horizontal stabilizer.
The motor mounting is such that the complete power plant may be removed by unscrewing four nuts.
The specifications for the "Butterfly," model "L," are :-
Span 29 ft. 9 ins.
Chord 84 ins.
Height overall 5 ft. 10 ins.
Length overall 19 ft.
Weight (gross) 978 lbs.
Useful load 9,383 lbs.
Loading per square foot 5-2 lbs.
Weight per horse-power 13-5 lbs.
Speed, maximum (horizontal flight) 72 m.p.h.
Speed, minimum (horizontal flight) 30 m.p.h.
Climb 4,800 ft. in 10 min.
Radius of flight, full load 6 hours
Motor Cato 68-70 h.p.