Some pilots elect to use tape or rock deflector guards  to protect the leading edge from rock/debris damage.  Regardless, taking proper care of the PPC propeller is  as critical as proper engine and wing care. The rear and front  wheels of the powered parachute  are an assembly and consist of a tire, a rim, and an  inner and outer set of wheel bearings. The wheel is  secured on a spindle and held in place by a nut and  a cotter pin. Each spindle is typically mounted on a  suspension system which provides elasticity and at  the same time is very strong. [Figure 3-18] The  sus- pension system varies by manufacturer from one cart  to another; refer to the POH for exact configuration  and components. Some powered parachute tires are  heavily treaded while others are smooth; pilot prefer - ence and the terrain type are determining factors in  choice of tire profiles. [Figure 3-19] Tire sealant or  thorn guards can be used to minimize flat tires. area of decreased pressure is in front of the propeller,  and the force (thrust) is in a forward direction. Aero- dynamically, the thrust is the result of the propeller  shape and the angle of attack of the blade. Axle and Wheel Assembly Figure 3-17. Airfoil sections of a propeller blade. Figure 3-18. Suspension system. Figure 3-19. Some powered parachute tires are heavily  treaded while others are smooth.  The typical powered parachute has a  ground adjust- able propeller. The adjustment of the propeller should  only be conducted to meet the engine manufacturer’s  maximum recommended RPM target. Pilots who are  not familiar with adjusting the propeller and how it  will affect the PPC performance should consult with  a knowledgeable source prior to making any propeller  adjustments. The engine mount is designed by individual manu - facturers for each cart configuration. The majority of  the total aircraft weight is determined by the engine  and mounting configuration. When trailering the PPC  over bumpy terrain or over long trips, the bouncing  of the cart in the trailer can put extreme stress on this  mounting system. In addition, repeated hard land- ings of the cart can also stress the welds of the engine  mount. Consistent detailed inspections of the engine  mount should be an important part of every preflight  and post-flight inspection. Just like an airplane propeller, the powered parachute  propeller turns at such great speeds that it becomes  invisible when in motion. The dangers of a turning  propeller require every pilot to maintain the highest  level of safety and respect for the consequences of  body parts, pets, and debris coming in contact with a  rotating propeller. Always treat the propeller as if the  ignition were on. Debris on the takeoff/landing field  is a danger to the propeller as well as to the people  who may be in the prop-wash area behind the pro- peller. Stones, small pieces of metal, and sticks can  become dangerous projectiles if kicked into the pro- peller during takeoff and landing. Just as with any  airframe or wing component of a powered parachute,  if the propeller becomes damaged, nicked or dinged,  the aircraft’s performance can be greatly affected.  3-9