How we make our parachutes
Classic Fruity Chutes have the classic ellipsoid shape of many military parachutes. The shape is similar to hemispherical but the top is flattened. This has the same drag coefficient as hemispherical but reduces the amount of material and lowers the weight. This design has several advantages over other designs:
- The shape has the theoretical maximum drag coefficient of 1.5 for vertical descent
- It uses the least amount of material for a given canopy size and load capability
- Has the lightest weight per load capacity
- Packs into a small volume
Our new Iris Ultra parachutes feature a pull down apex design resulting in even higher efficiency. This allows a smaller parachute to do the same work as a larger chute.
The drawing below shows the major components of the parachute and relative dimensions.
IMPORTANT: Fruity Chute diameter is the actual opening size of the parachute, not the distance around the top of the canopy!
The Canopy consists of multiple gores shaped so when sewn together it forms the ellipsoid shape. The seams used are called a "Flat Felled" seam which has the advantage of being double stitched and having four layers of material. As a result, the seams are much stronger than the material.
As the parachute size goes up the number of gores increases. This allows more connection points to the parachute and keeps the load capability per shroud line more constant. Small chutes have just 8 gores, while our 192" parachute has 18.
The material used is 1.1oz calendared rip stop and meets Mil Spec PIA-C 44378 Type IV specification. This is a process where the nylon is rolled under heat and high pressure to lower the porosity of the nylon without the need for coatings. The result is a very strong light weight fabric with low permeability. If you get a hole or tear in the rip-stop it does not spread.
Our standard design comes with a spill hole that is 20% of the diameter of the canopy. It is just 3% of the area. A spill hole further increases the stability of the parachute and keeps it from "puffing". The spill hole is reinforced with bias tape to ensure maximum strength. Large chutes also come standard with a deployment parachute connection loop sewed onto the bias tape reinforcement.
Shroud Lines & Canopy Connection
Shroud lines for larger chutes are made from 400 lb test IIIa Paraline. Our Iris chutes can also be ordered with high strength Spectra lines for a much lighter and smaller size. The connection to the canopy is sized to the chute. The connection to the canopy is triple stitched for maximum strength directly to the parachute seam using Grosegrain tape reinforcement. Standard shroud length is 115% of the canopy diameter.
The shroud connection pattern we use is called a "hand bag" closure. Rather than each shroud line connecting as a simple loop to the seam next to it, the lines connect from one side of the parachute to the other. If you picture the parachute being folded like a taco, the shroud lines connect from the seam on one side to the seam on the other side. This lets the lines be more easily untangled if the bridle slips through the lines. You can also easily undo the bridle and untangle the lines. Please email us if you want some tips on how to do this.
Fruity Chutes come standard with all the shroud lines connected to a high-strength bridle. The bridle is constructed using heavy nylon webbing that terminates to a swivel. The strength of the materials is designed to allow for a shock of as much as 50x the descent rating of the chute. For instance the 144" and larger parachute uses a marine stainless swivel with 6000 lb shock strength and 1" nylon webbing- truly the finest in the industry.We can custom make bridles, let us know what you want.
120" Parachute Bridle. Note two bundles of shroud lines. One bundle to
the left side of the chute, the other bundle goes to the right side.
Analysis of many flights of Fruity Chutes descent rate has verified that the Cd of Fruity Chutes is 1.5 for Elliptical, or 2.2 for Iris Ultra, which is the very close to the theoretical maximum for parachutes. You can closely predict your descent speed within 10% or better using Rocksim by setting your Cd to this value. See the screen shot below how to properly model a Fruity Chute.
Remember, this descent speed is for sea level. It will go up as elevation increases.
Descent Rate Calculator - Use this handy online tool to exactly calculate the performance for any Fruity Chute.