Over the course of a season we see many people who struggle with their canopy control after downsizing too rapidly. In an effort to help jumpers choose their equipment wisely for optimal learning and skill building, we have combined information from AXIS Flight School, the USPA SIM, and the FFP (France).
The calculator above creates suggestions for the sport as a whole. By referencing your body weight and experience, the chart will present you with the minimum recommended square footage of the canopy you should be flying. Canopy model considerations should be addressed with an experienced canopy coach.
Meeting the threshold of a downsizing step in the chart does not grant the user permission to do so: jumpers need to be current and demonstrate superior flying ability on their current wing. We urge jumpers who think about downsizing to contact a qualified canopy coach and/or S&TA. Have him/her evaluate your skill level with your current wing before flying a new one.
It is always acceptable and encouraged to fly a larger canopy than indicated on the graph. Be aware that no matter the size or wing loading of the canopy model you are downsizing to, that you will be taking on additional risk from the canopy model you jumped prior. The muscle memory developed to pilot and land the larger canopy may be inappropriate for landing a smaller, higher performing canopy.
The calculator works on data avaiable through the FFP (see below). The data base encompasses bodyweights from 60-110kg (≅132-243lbs) and jump numbers from 0 to 2,000.
For bodyweights below 60kg (≅ 132lbs) the data for 60k (≅ 132lbs) will be shown. The calculator does not work for bodyweights above 110kg (≅ 243lbs). If a higher number is entered, a warning will be displayed and the calculator will be reset to 110kg (≅ 243lbs).
There is no recommendation for skydivers with 2000+ jumps but they still need to be current and have superior flying ability on their current wing before downsizing.
Here are some useful sections from the USPA SIM that relate to the topic:
The «Derective Technique N° 48» (DT48) of the FFP addresses the topic of downsizing. In France this is a regulation and not a suggestion.
When we looked at the graphs and table they provide, we found that much of what was said there corresponded to our experience with hundreds of students at AXIS Flight School. Which is why we decided to adopt their downsizing table for this tool.
The DT48 allows a further reduction of 10% of the canopy size when authorized by the French equivalent of an S&TA. AXIS Flight School is considering a similar variation which might also take into account the USPA License of the jumper.