Piasecki HUP Landing Gear

12 January 2006: Corrected three-view illustration

For more information on the interior and exterior, click here: https://tailhooktopics.blogspot.com/2016/04/piasecki-hup-interior.html 

An aircraft's landing gear is often inaccurately depicted in a model aircraft kit for various reasons, but primarily due to reliance on a museum example that does not have properly inflated struts. Helicopter landing gears are even more likely to be incorrectly represented on a model particularly when they involve multiple small struts for which proper alignment features (or adequate illustration in the assembly instructions for that matter) are provided.

The Piasecki HUP main landing gear is an example. It consists of a main shock strut that is mounted upside down (the piston extends out of the top of the strut) with lateral and longitudinal loads reacted by two small struts attached to the bottom of the fuselage that are joined together at their outboard ends and attached to the bottom of the strut shock with a yoke.

 When the strut is properly serviced, on the ground there will be 2.1 inches of chrome-plated piston above the cylinder and the top of the chrome will be 12.44 inches from the attach point of the strut on the fuselage.

 Note that longer lateral strut is mostly hidden behind the short one from the side:

Also note that when the HUP is off the ground, the wheels drop down about 11 inches (note the additional chrome showing on the piston) to provide the shock absorption of a high sink-rate landing.