Editing Parachute (section)

=== Pull-down apex ===
[[File:C._1970s_'High_Performance'_canopy.jpg|thumb|1970s 'high performance' pull-down apex canopy, as seen in the 'round' (or really, elliptical) parachute's centre.]]
[[File:1970s 'High Performance' round elliptical.jpg|thumb|1970s 'round' elliptical showing 4 controllable turn slots, plus another, small side vent and one of 5 rear vents.]]

A variation on the round parachute is the pull-down apex parachute, invented by a Frenchman named Pierre-Marcel Lemoigne.<ref>Pierre Marcel Lemoigne, {{US patent|3228636}} (filed: November 7, 1963; issued: January 11, 1966).</ref><ref>{{cite web |first=Jean-Michel |last=Palau |url=http://jmp-pan.blogspot.com/2008/02/historique-du-parachutisme-ascensionnel_988.html |title=Historique du Parachutisme Ascensionnel Nautique |date=February 20, 2008 |access-date=October 22, 2013 |publisher=Le Parachutisme Ascensionnel Nautique |language=fr}} Includes '''photo''' of Lemoigne.</ref><ref>See also: Theodor W. Knacke, "Technical-historical development of parachutes and their applications since World War I (Technical paper A87-13776 03-03)," 9th Aerodynamic Decelerator and Balloon Technology Conference (Albuquerque, New Mexico; October 7–9, 1986) (New York, N.Y.:  American Institute of Aeronautics and Astronautics, 1986), pages 1–10.</ref> The first widely used canopy of this type was called the ''Para-Commander'' (made by the Pioneer Parachute Co.), although there are many other canopies with a pull-down apex produced in the years thereafter - these had minor differences in attempts to make a higher performance rig, such as different venting configurations. They are all considered 'round' parachutes, but with suspension lines to the canopy apex that apply load there and pull the apex closer to the load, distorting the round shape into a somewhat flattened or lenticular shape when viewed from the side. And while called ''rounds'', they generally have an elliptical shape when viewed from above or below, with the sides bulging out more than the for'd-and-aft dimension, the [[Chord (aeronautics)|chord]] (see the lower photo to the right and you likely can ascertain the difference).

Due to their lenticular shape and appropriate venting, they have a considerably faster forward speed than, say, a modified military canopy. And due to controllable rear-facing vents in the canopy's sides, they also have much snappier turning capabilities, though they are decidedly low-performance compared to today's ram-air rigs. From about the mid-1960s to the late-1970s, this was the most popular parachute design type for sport parachuting (prior to this period, modified military 'rounds' were generally used and after, ram-air 'squares' became common). Note that the use of the word ''elliptical'' for these 'round' parachutes is somewhat dated and may cause slight confusion, since some 'squares' (i.e. ram-airs) are elliptical nowadays, too.