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Cronk works
David Cronk’s hang gliders
In 1971, a new kind of aviation was beginning, or rather re-emerging after it was forgotten when the Wright brothers successfully added engines and propellers to their biplane glider nearly 70 years before. The new technology of hang gliding found a number of its early leaders on and around the beaches of Los Angeles county, southern California. One of those leaders is David Cronk, who in 1975 additionally became the first ever world hang gliding champion.
Cronkite
I NEVER intended to get this high above the ground.
— Dave Cronk (e-mail correspondence, 2020)
The Cronkite 2 of about 1970, here flying at Redondo Beach, featured a ‘parallel bars’ style hang cage.
Spoilers at the wing tips, operated by an ingenious system of shoulder-pressed levers, provide good turning control.
— According to Paul Wahl writing in Popular Science, June 1972
By this stage, a triangular control frame replaced the hang cage.
See also the short low-resolution digitized film by Carl Boenish on YouTube for Dave Cronk flying this wing at Torrey Pines, set to a 16th century English folk ballad instrumental (under External links). See also the Torrey Pines page.
Chuck Slusarczyk’s Falcon was a bird-like wing similar in concept to the Cronkite. See the page Chuck’s Glider Supplies of Ohio.
Torrance Beach, about 1973 or so. Carl Boenish set up a keel mounted camera, and we got this great shot. Jack Schroeder and Danny Bostwick flank both sides on a beautiful, post-storm day.
— Dave Cronk (e-mail correspondence, 2020)
Dave Cronk, Bob Lovejoy, and the Quicksilver
This was Quicksilver prototype #1. Bob and I had only flown this glider off of Playa Del Rey CA (Dockweiller). I went first, and found myself dumbfound (and terrified) by quickly rising above the ridge and gaining perhaps 100 feet. This glider had a very marginal structure, and used clothesline pulleys and string for controls. After this flight, I took it back to the shop and immediately began improvements.
— Dave Cronk
Quicksilver #2, Playa Del Rey, CA, about 1972-73. Based on our prototype (Bob Lovejoy and myself) I added two feet of span, bringing it to 32 feet. This still incorporated the laminated wood battens (or ribs) that flattened when damp. I also upgraded the rudder with a rigid trailing edge, stiffened up the empennage system with double wires, and generally upgraded everything that was sketchy in the original.
Bob Lovejoy did not stay involved in hang-gliding after his first design effort. Although he was a partner in Eipper-Formance, he never got back into the sport, or the hang glider design world.
Bob was a brilliant toy designer at Mattel Toys, and had a great reputation there.
— Dave Cronk
For more about Bob Lovejoy, see Project Quicksilver in Hang gliding before 1973 part 2.
See also Hugh Morton’s photos (related topics menu).
I had increased wing spar size, added a second lift-cable bay, increased cable diameter, upgraded the rudder control system components, and generally brought things up to a point where I felt confident flying well-above the ground.
— Dave Cronk
In later life Bill Liscomb created the film documentary Big Blue Sky, in which David Cronk is interviewed about the early days of hang glider development and the flying at Torrance Beach.
I had the luxury of designing and flying a wide range of Quicksilver variations. Sometimes I would design for a particular site, person, or event.
— Dave Cronk
This was my final Quicksilver glider design. By this time (about 1977) flexible wing glider performance had surpassed the best Quicksilvers. I flew them mostly for soaring in smooth lift sites, like Torrey Pines.
— Dave Cronk
It’s hard to believe that this monster, a modern Quicksilver derivative, is fully based on the original 1971 prototype. 1200 lbs, 100 hp.
— Dave Cronk
Variometer
A vario system I set up in the early 70s. This is the earliest use of a vario in a modern hang glider that I am aware of. I used it at the Annie Green Springs prelim test meet practice session.
— Dave Cronk
Annie Green Springs (a wine label of the commercial sponsor) was the U.S. national hang gliding championships of 1973. See the Variometers page for more.
Cronksail
Dubbed the “Cronksail” by Joe Faust. Inspired by seeing Richard Millers’ seminal Conduit Condor. This image shows very early preliminary tip-rudders that were subsequently refined. Prototype #1 was literally run over by a Greyhound bus on the 405 freeway when the glider came off the racks on the way to its first test-flight. Good knot tying skills are important.
— Dave Cronk
The Mitchell brothers were well known Seagull (of Santa Monica) fliers.
That must be Santa Catalina island on the horizon. See also the Domes, Palos Verdes related topics menu.
Eipper Cumulus
The first ever official world hang gliding championship was held at Kössen, Austria, in 1975. Dave Cronk won it in an Eipper Cumulus 4.
Cumulus 4. This design was the first in the industry (I think) to use high strength 2024 T3, thin-wall tubing.
— Dave Cronk
There are two video clips of Dave landing this wing at this event under External links.
World largest hot air balloon at the time c1976 or so. All Cumulus 5s and 5-Bs. The “B” added tip battens and increased tip chord. A very popular line of gliders.
That’s Dave Cronk in his Mendij-painted Cumulus VB at left (partly obscuring another wing). See also the Hang glider sail art related topics menu.
Joe flew this glider off the low hill in Crestline this day: The glider’s first flight since 1978 or so. Mendij painted this for me. It took roughly 2 months of painstaking tapping and rubbing in oil paint, both sides.
— Dave Cronk (via e-mail, March 2020)
See Our Vintage Fly-In under External links later on this page for video of Joe Greblo flying it in 2010.
This was the last of the Cumis, in a long line of successful gliders.
Related
Eipper-Formance of Torrance, California
External links
Air-Tech Inc. Ultralight Aircraft
Austria World Hang Gliding Championship 1975 AP Archive video on YouTube starting at 12 minutes 3 seconds: Dave lands the Cumulus 4 and is then interviewed
Austria World Hang Gliding Championship 1975 AP Archive video on YouTube starting at 14 minutes 29 seconds: Again Dave lands the Cumulus 4…
Austria World Hang Gliding Championship 1975 AP Archive video on YouTube starting at 15 minutes 31 seconds: Dave interviewed about the result
Hanggliding Worldcup 1975 (Drachenflug WM 75 Kössen in Tirol) digitized film ‘Free as a Bird’ by Julian Grant on YouTube starting at 42 minutes 23 seconds (narration in German)
Hang Gliding – Hackler’s Fly-in, 1976 digitized film on YouTube starting at 1 minute 13 seconds; Eipper Cumulus 5Bs and Quicksilvers mostly
Our Vintage Fly-In by Ken Westfall starting at 4 minutes 9 seconds for Joe Greblo and Mike Quinn flying the Mendij Cumulus VB at Andy Jackson Air Park in 2010
Playground in the Sky, 1977, by Carl Boenish on YouTube (low resolution) starting at 25 minutes 19 seconds for Dave Cronk flying his Cronkite (followed by Volmer Jensen in the VJ-23, then Taras in the Icarus 2 and Icarus 5…)
Big Blue Sky video external links
These are links to Big Blue Sky — The history of modern hang gliding – the first extreme sport!, 2008, documentary by Bill Liscomb on YouTube:
- Dave Cronk describes how he started: Big Blue Sky starting at 17 minutes 33 seconds
- “Dave describes his early experiences of soaring the cliffs connecting Torrance Beach and Redondo Beach”: Big Blue Sky starting at 24 minutes 13 seconds
- First World Champion, 1975, David Cronk in Big Blue Sky starting at 44 minutes 21 seconds
Response to Cronk works
rochellecronk1 says:
March 26, 2020 at 22:26
Most talented man ever!! Wish I could have seen this all in person!
Hang Gliding History 
On a flying trip to the Chattanooga area in ’78, one morning, still in bed in the flyers bunkhouse, I listened to Chuck Toth negotiate the sale of his all yellow Cumi-10 to a guy outside. Chuck ran the Crystal Hotel where we all stayed. 6 months later, flying in West Rutland VT, by pure chance, I met the guy who bought it. I shared several thermals with the guy, and boy that glider thermalled great. A real beauty. I had no idea it was a Dave Cronk design.
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Thanks Chris. Incidentally, there are some photos of the flyers’ bunk house, taken about three years later, under From our house to bunkhaus in Hang gliding early 1980s part 2.
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