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MODIFIED LONG-EZ NOW APPROVED FOR GRASS FIELDS
Rutan Aircraft has recently tested
a spring loaded "shock strut" which was installed in place of the NG-9 / NG-1OA
rod on Long-EZ. This, combined with 500 x 5 main tires, was tested by progressively
taxiing over 1" x 2", 2" x 4" 's and finally over two 2" x
4" s, one on top of the other. The results showed a very significant increase in the
roughfield absorption qualities of the landing gear. Taxiing over stacked 2 x
4s resulted in very acceptable loads, with a satisfactory ride.
We then flew N79RA to an average grass strip and conducted takeoffs and landings at a range of weights and cg positions. Also, taxi test in tall grass and undulating surfaces was satisfactory. A Long-EZ with the spring strut and 500 x 5 main tires is now approved to operate from average grass fields. This does not mean it is acceptable for gravel or unprepared/rough surface. The prop damage that can result from operating on gravel is unacceptable.
The spring strut is installed by simply removing the 2 bolts on the NG 10A pushrod and replacing it with the spring assembly. Additional clearance is required by trimming away a portion of the strut cover.
The spring is intended primarily for the Long-EZ to give it the grass capability, however VariEze owners may want to install it to improve the rough field handling of the nose gear. The spring allows the gear to deflect aft and up when a bump or hole is encountered, and greatly reduces the loads on all parts (strut, NG10A castings fork and wheel). The Long-EZ fiberglass strut is stiffer than the VariEze, thus the new spring is strongly recommended unless you plan to always operate from smooth surfaces. Without it, nose gear damage may occur from rough surfaces.
Note: This is not intended to provide grass field capability for the VariEze. Its faster takeoff/landing speed and inability to use 500 x 5 tires makes it unacceptable for grass.
The strut, ready to install, is being made available by Ken Brock. Ken will also stock the LST-6 spring for those wanting to build their own. Refer to the drawing in this newsletter. Several different spring configurations were tested until arriving at the 1.5 x 4" heavy-duty rectangular coil spring. If building your own, shim as required to obtain the specified 250 lb. Pre-load. The strut should not deflect when static with pilot in cockpit and full fuel.