Sunday, 14 January 2018
Ages ago I came across this great video from the UK High Altitude Society 2015 conference about crossform parachutes and their use. Its a fantastic short talk by Ed Moore and explains why the crossform chute is a good choice as it balances the factors of ease of construction and performs well with much less spinning/gliding and coning... the TL;DR is use these and have less area to search or less distance to walk to recovery!
The video of the talk is online and I found that over the last couple of years I've gone back to it and rewritten a load of notes from it which promptly disappear into the piles... so this time I thought I'd type them up, add diagrams and share them. Beyond just sharing notes, Ed's fabulous talk presents the math required to design a crossform chute but he doesn't go through a full example process. I have done this in this document and hopefully included every step of the math! Much of the maths can also be applied to other parachute designs. The document is open source and available as a pdf and as a libreoffice odt file on this Gitlab repo (EDIT.. I've since added a spreadsheet in ods or xslx format that does the calculations for you!) https://gitlab.com/concreted0g/crossform_parachutes