Wing Loading Charts
The wing load is the ratio between suspended weight of the jumper and the square footage of the canopy. To calculate the wing load, add up the jumper's fully geared up weight minus the main parachute and divide by the square footage of the canopy. The resultant number is the wing load. It is expressed as that number to 1.
Example: Lets suppose that the weight of a jumper fully equiped (exit weight) is 215 lbs while jumping a 7 lbs canopy. The suspended weight of this canopy is then 215 – 7 = 208 lbs. With a canopy size of 170 square feet, the calculated wing loading will be : 208 lbs/170 s.f = 1.22 lbs/s.f which means that the wing loading is 1.22 to 1 (or 1.22 lbs for 1 square foot)
The following charts are guidelines from the industry and collected from experience for the selection of canopies based on type of material and wing loading.
F-111 versus Zero-P
|Minimum Ratio||Maximum Ratio|
0.7 to 1
1.1 to 1
0.9 to 1
1.4 to 1
Factors that affect the Ratios
|Factors||Lowers the Ratio||Raises the Ratio|
|Decision Making Speed||slower||faster|
|higher ASL||lower ASL|
|Size of Landing Area||smaller area||larger area|
|Number of Alternate Areas||lower number||higher number|
|Size of Alternate Areas||smaller size||larger size|
About canopy sizes? Although you can fly it, can you fly it ALL THE TIME? Although you can fly a canopy and land with a high perfomrance landing really well, the question is would you want to jump this canopy all the time in the variety of wind, traffic, and terrain conditions that you will encounter? The margin of error is potentially decreasing drastically. Remember, it is your skill that will possibly save you, not the canopy.
Other considerations for wing loading:
- the implications of being hurt as they relate to your job
- the additional needs of your family, not only yours
- if you intend on doing exhibition jumps with this canopy
- the DZ elevation of intended skydiving vacations
- conduct a personal risk management assessment evaluating all factors