varmit

Yes, there was a DH Heron used as a jump aircraft in the central US in 1985. It was based at my "home" drop zone of Chandler, Oklahoma, at the time. The plane was built, originally for commuter airlines. The power plant was a little odd. The plane had 4 Lycoming piston engines of about 280 HP. The plane was VERY slow climbing - It seemed able to only climb when flying in a straight line. The spar, across the floor was in the way of exits. Yes, the plane had to make a low pass at about 9000 ft to put out part of the load to be able to climb on to 12000 ft. With 4 engines, it was quite fuel hungry. All combined to make a poor jump plane. The group that bought the plane never made any money with it. the plane was repossed during the winter of 85-86.

Actually some Divici drawings show crude ram air designs, but actual R& D started in the mid to late 60s. The first "jumpable" ram air canopy was probably the Volplane, which I believe was manufactored by Pioneer. In this time period the slider had yet to be invented so each manufactorer came up with their own unique reefing system to slow the openings. The Volplane had a small hydraulic cylinder (about 8" long) sewn to the bottom canopy skin. A 1" steel ring was sewn to each "A" line near the canopy line attachments. The rings were stacked into a crab claw fitting on the hydraulic cylinder. The fitting was closed and the cylinder pumped up to pressure with a handle attached to the cylinder. The more the cylinder was pressurized, the slower the opening - in theory. The original versions of this thing had really long lines, about 30 feet. Another early "square" was a Barish Sailwing. This was a real oddball in that it was a single surface (no cells) canopy. It had really tall ribs attached to the bottom of the single skin that would trap enough air to inflate the thing- sometimes. These were probably the most unreliable canopy ever made. By the early 70s there were numerous makers of squares. Some were real companies and some were just cottage shops making copies of other companies designs. In general, most all of the marketed mains from the early 70s until the ZP days, were bulky to pack, slow flying, docile and reliable.