[JoeF]

Let's follow his development of a short-pack hang glider.
Anyone?

[JoeF]

https://www.dynamicflight.com.au/_files ... c6c8a5.pdf
His words of wisdom for competition hang gliding pilots is in the document. But there are things in that wisdom for recreational hang gliding pilots.
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Digesting from his Facebook notes:

Shown is not his, but he seems to be taking some inspiration from the shown:
https://www.delta-club-82.com/bible/331 ... er-ef6.htm

He has some neat success in his Bak Pak Yak. "Some of you may be wondering why the name Bak Pak Yak?
It is because our kayaks rapidly deploy from a backpack, 9kg including bag

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Facebook post:

Rohan Holtkamp ...
I’ve spent 33 years full time HG instructing (> 3000 students) 15 years on the National board, 25 years design and manufacturing safer harness and wheels and comp flying since 1987.
I’m developing a HG that sets up in two minutes from a 1800mm 15kg pack. Flaps. Tip drag roll & glide slope control 80kph VNE, 0.7m/sec sink rate.
It will best soaring PG in every metric, anything less is a waste of my time.
So I’ll stop wasting time writing and head out to the workshop. Load testing 2025.

[JoeF]

He notes in his Facebook flow:
April 2025
Dynamic Soarer
"...I chose to replicate the planform and profile of the Atos CV in the first Dynamic Soarer."
Caution: he may have further versions in mind with possible altered planform (see above post).
He stated firmly that he is "still working on the DS, key components have been finalised after load testing several dozen hand made prototypes."

From his comments, I guess he will be 3D printing some components.

Note: "Dynamic Soarer" is a name historically used in other context in aviation.
Note: https://en.wikipedia.org/wiki/A-I-R_Atos article as yet does not specify CV, but does a V.
Note: https://www.air-atos.de/en

[JoeF]

Rohan Holtkamp wrote about his adventure into lighter HGs in Sept.3, 1991 in Facebook:

Maybe its time time to offer background then more details on my Dynamic Soarer homebuilt hang gliders.
For those who don’t know, the first three hang gliders I successfully flew were home made rigid wings designed by Ewen Fagan, I customised each of these in pursuit of less weight, better performance and or pack up time.

I flew five or so years of comps from 1986 on these until sponsored to fly “normal” hang gliders.
The roll control and glide slope control of the EF’s remain unbeaten even today, you could land them on a fencepost in turbulent air or on the roofrack of a stationary vehicle. Some EF pilots often did.

Weight, set up time, static balance and high parasitic drag prevented them becoming popular.
I’ve been contemplating rectifying these shortcomings since 1986 while flying competitively, instructing, sitting on our federal board, safety and operations committee, conducting accident investigations, test flying, advising, developing and improving hang gliders from floaters to HP. All these activities were and still are in pursuit of. Growing Hang Gliding
My design employs a planform loosely based on the EF6, albeit not as tapered, fractionally less dihedral, about the same sweep, more span and significantly less external wires. The EF had a total of 28 external wires, current floaters have 14 including luff lines.

Dynamic Soarer is braced with UHMWPE cable stringers, spar caps, diflexors, anti drag, tortion control and leading and trailing edge members - all inside the sail. This leaves scope for planform adjustment and or size variation in future versions. The spar is externally braced like most kingposted hang gliders with the addition of a bowsprit assisting anti-drag and AOA control out to the side “wire” mount points.

Manual calcs, finite element analysis and dynamic platform testing will help set the finer construction details but the longest part of the packed airframe is 1950mm as of today, the weight will be less than 15kg and the set up time will be close to the aforementioned 2 minute mark.

In a reply to a question in 1991:

should get 13 to 1 with 5 degrees washout comfortably and 4 at full “flaps”- max washout.

We seek updates from that 1991 review of his design 6' 5" pack adventure.

Aug 2021 we find Rohan saying in a post:

For those that haven’t seen my post on FB groups:
Ive finally found a few hours to start building a hang glider I’ve been contemplating the last 35 years. I’ve built a 10th scale model, then 1/5th scale model and now some full scale components for load and function testing.
Design goals:
Pack to 2meters long in two minutes, from flying configuration. Weight 14kg or less. Min sink less than 200fpm. Best L/D greater than 13:1 with landing config 4:1
Control option with drag brakes sim PG so easy conversion for PG pilots . 52mm OD and 54mm OD 7075 tube required.
Late August update. Proto has 62mm spars, 3850 grams per side with sleeves, rivets and fittings- 6.4m keel to tip. Aspect 13. Sail weight approx 3kg (15m2 area chordwise tension - like Atos). Working on keel, control frame, KP and bowsprit assembly, 5th iteration the last week.
Aforementioned design goals still on track.

15 degrees sweep, 5 degrees dihedral, 6.5m keel to tip, 15m2 area, root chord 1300mm, outboard rib 1000mm king post and bowsprit. Spinnaker sailcloth, - like sturdy PG sail.

Caution: the following is an AI workover of that sentence:

The design has a 15-degree sweep and a 5-degree dihedral. The span from keel to tip is 6.5 meters, which is about 21.3 feet, so the full wingspan would be about 42.6 feet. The total wing area is 15 square meters, or roughly 161 square feet. The root chord is 1300 millimeters, which equals about 51 inches, and the outboard rib chord is 1000 millimeters, or about 39 inches. The setup uses a kingpost and a bowsprit. The sailcloth is spinnaker fabric, similar in sturdiness and feel to paraglider sailcloth.

That seems to be about aspect ratio of 11 or so.

[JoeF]

Continuing research over Rohan Holtkamp'ss design adventure.
In a reply he said about twist: ""

starting with 7 degrees at zero “flaps” and 22 degrees at full.

In a reply to someone about setup time:

2 minutes. No control frame pins or bolts to assemble, no need to roll over, no battens to pull out, sort or insert, no luff lines to hook up.

Rohan confirmed bowsprit to a questioning person.
Rohan 4 years ago was looking into copyright and patent matters.
My research today in Australian patents does not find any patent for Rohan Holtkamp.

[Bob Kuczewski]

https://www.dynamicflight.com.au/_files/ugd/209769_4a043cf9712a40fe88fb565dbac6c8a5.pdf
His words of wisdom for competition hang gliding pilots is in the document. But there are things in that wisdom for recreational hang gliding pilots.

There are lots of words of wisdom in that article. I've attached the PDF below in case the original ever disappears.

I mostly skimmed it, but I did notice a few typos, for example:

Anyone can fly when it’s easy. Anyone can fly in 100fpm lift, or 500fpm, or even 250fpm. The time that it gets interesting is when the ceiling gets down to 3000ft and you have 100fpm lift. Competitions are often won and lost on such days.

The first value should probably be "1000fpm", so read it critically.

Also, the abbreviation "S2F" is probably "Speed to Fly".