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These requirements were adhered to for many years. Today, containers achieve the required holding and deployment needs through design tailoring. The bottom corners of the reserve container are designed so that the bag is held in place while the pilot chute and bridle deploy and then releases the bag, rotating it out of the container top to bottom into the airstream. At the same time, the bag can still deploy quickly in the event of a horseshoe-type malfunction. 

The main container is less restrictive than the reserve in holding the main canopy in place during deployment. This is important so that there is no tendency for the bag to twist or be unstable on deployment. With many of the main canopies used today, if the bag is unstable, it results in the main canopy opening unevenly and causing spins and possible malfunctions. Along with the main bag, the main risers must be able to deploy evenly for the same reasons. 

In the early days of skydiving, the primary body position was a stable, face-to-earth position. This resulted in the main container being behind the parachutist out of the airflow. One of the primary problems faced during those days was the high incidence of pilot chute hesitations. This was the result of poor training and lack of understanding of that air flow. Eventually skydivers learned to sit up during deployment causing the air to flow over their back sweeping the pilot chute into the main stream. Hand deployed pilot chutes were developed to make packing easier and eliminate the need for a metal ripcord. 

In the face-to-earth position, the primary purpose of the container is to hold the canopy and pilot chute closed, and then allow it to open during deployment. Today, body positions experienced during free fall range from head-down to feet-to-earth and everything in between. Where speeds formerly experienced ranged from 110 miles per hour (mph) to maybe 140 mph, today speeds in a head-down position can exceed 200 mph. This has changed the container dynamics to ensure a more secure system and increased protection from the wind blast. These changes have resulted in more secure and streamlined configurations to accommodate these new requirements. Figure 2-13  shows a modern container design shaped to meet the high-speed airflows of today. 

An additional area that needs to be addressed when designing piggyback systems is the main riser covers. In the early days of sport piggyback designs, the main risers were held in position by webbing keepers. As the sport progressed, the use of fully enclosed main riser covers became the norm. In their attempt to protect the main risers during high-speed free fall, some designs tend to restrict the deployment of the reserve container in the event of a “total” main pack malfunction. When this happens and the main container remains closed, the main riser covers do not open. Because of this, there is additional restriction over the upper corners of the reserve 

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container. This contributes to higher reserve bag release forces. In severe cases, this can result in a reserve pilot chute in tow with potential serious consequences. The balance between sufficient main riser protection and the requirement for unhindered reserve deployment is a critical design feature. 

Most modern sport parachute containers have housings of some sort to accommodate ripcords and riser release cables. These flexible metal conduits come in 3 basic types in varying diameters: non-compressible, relaxed, and non-extendable. The housing type is critical to provide proper protection and function for the usage. Non-extendable is used for most ripcord housings, except on Navy seat packs. Relaxed refers to the ripcord housing that is not completely compressible. Non-compressible housing is the correct type to use for 3-ring cutaway systems so the compression does not cause the sides to release unevenly. 

## Harness Design 

According to Poynter’s Parachute Manual, “the harness is an arrangement of cotton, linen, nylon, or Dacron$^{®}$ webbing, which is designed to conform to the shape of the load (usually the body), to be carried in order to secure it properly so that the opening forces and the weight of the load are evenly distributed during opening and descent.” 

