The old adage that you “can’t fit a square peg into a round hole” doesn’t hold true for Parker LORD. At least not when helicopters are concerned.
We’ve upgraded the elastomeric pad on the Bell 412 Aft Landing Gear Strap to better accept the load of the helicopter’s aft landing gear cross tube. Essentially placing a round object on a flat surface with little to no displacement or shift.
The landing gear cross tube is flexible and bends as the helicopter lands and again as it leaves the ground and rises into the air. The surfaces of the cross tube and the landing gear strap bumper only meet when the helicopter is in flight. Contact is either “full load” or “no load”.
Because of this gap a build-up of debris, oil and water will develop on the surface of the pad that resides in the “cradle” of the landing gear strap—degrading the pad over time.
Due to previous design specifications, the pad was engineered with metal shims between the layers of elastomeric material. Today, the pad has been reengineered with fiber-enhanced shims, eliminating the potential for metal-to-metal contact and the possibility for abrasion and degradation.
The new fabric shim construction contours better to the cross tube, providing an enhanced stability derived from a more uniform load distribution and increasing service life. The new fabric shim design provides at least three-times more life than the previous metal-shimmed version.
Data comparing the two pads shows a definitive improvement after 50,000 fatigue cycles. The photos here show that the fabric-shim construction is more contoured with less rubber material displaced by the cross tube.