Parks College Parachute Research Group
Canopy Maneuver Study
Investigator: Gary Peek
Goals:
This study was undertaken to learn the risers forces of a canopy in flight and to graph
specific flight maneuvers as an overall test of the sensitivity and accuracy of the
instrumentation used to record canopy flight data.
Test jumps performed
Due to the success I had in recording my first test jump and the limited availability of the
riser load system, I stopped after making only two instrumented jumps on a Performance Designs
Stiletto 150. This canopy was connected to the standard PRG riser load instrumentation,
which contains load cells attached to all 4 risers and a portable data logging system. The
sample rate from the load cells was 10 times a second and the gain of the amplifiers was
increased above that suitable for opening forces. This allowed the forces generated during
canopy flight to be displayed with an increased amount of resolution compared to that of
opening forces.
Here is an annotated graph of riser forces during one of the
canopy maneuver flights of a Stiletto 150 with a 1.7 wing loading.
This graphics file was constructed from multiple screens of the plotting program where
different periods of the flight were displayed on the different screens. The opening forces
were off scale due to the increased gain selected to favor canopy flight rather than opening
forces, therefore I included a reduced scale area in the graphics file that displays the peak
opening forces.
From the graph, one can tell, among other things, 1. when the deployment snatch force
occurs, 2. canopy spreading forces, 3. turn on opening, 4. forces involved with: A. brakes
stowed, B. full flight, C. hard toggle turn, D. deep brakes, E. multiple back-to-back turns.
Further research to be done:
As time and the availability of the riser load system permits, it is expected that a wide
variety of canopies will be jumped to determine their riser load characteristics in flight.
For questions or comments about this study contact Gary Peek at
peek@pcprg.com
