The Ho III 1938 Rhön Contest Challenger
We had planned an enlarged version of the Ho II with 20 meter span for some time, but feared that the "middle-effect" would cancel out other aerodynamic advantages. The parabola shaped center section was considered and rejected, due to our limited knowledge of possible side effects. We finally settled for the slightly enlarged Ho II.
The root chord was reduced, giving the wing slightly less taper, and also increasing the aspect ratio.
Two aircraft were laid out; the first with ear-shaped additions to the elevons to reduce adverse yaw in a rear c/g configuration, the other with a "fore-wing" mounted above the nose in a further attempt to combat the "middle-effect".
To minimize the washout step created by the up elevons during slow flight, two sets of elevons were used; the inboard set with less up and more down movement. All control rods were equipped with ball bearings to avoid the friction problems of the H II.
The selection and training of the contest pilots began four months before the contest. Three Ho II's were used by four candidates. After four weeks, the first Ho III was added, giving each pilot his own aircraft. They practiced cross country and instrument flying, and knew that if their instruments failed while in the clouds, they could simply pull the stick all the way back to remain below red line speed without any danger of spinning.
Following a cross country flight task into the wind from Bonn to Cologne, two of the pilots declared the task impossible, while the other two, Werner Blech and Heinz Scheidhauer, landed in the Cologne area; Scheidhauer after a nine hour flight. Our pilot selection was thus determined.
The second Ho III was finished just before the contest. D-12-348 was to be flown by Blech, while Scheidhauer would fly the older D-12-347. Another Air Force Unit entered the Ho II D-11-187 piloted by Kurt Hieckmann.
The two Ho III's established themselves somewhere in the middle of the standings during the contest. Blech had some noticeable altitude flights on instruments, while Scheidhauer's efforts were directed towards cross country flights. The Ho III would outperform the conventional sailplanes in thermals, due to its ability to make tight coordinated turns. The Ho II also did quite well, despite its inexperienced pilot.
The contest did not end without tragedy:
On August 6th, a large cumulus cloud was building over the Wasserkuppe, attracting several gliders, including both the Ho IIIs. While they were inside, the cloud quickly developed into a massive thunderstorm, unexpected and not in the weather forecast.
After about one hour, an Ho III became visible, obviously out of control, and hit the ground near Poppenhausen. It was Blech's machine, empty, the canopy and parachute was missing, - apparently a normal bail out. The aircraft was full of holes from hail, otherwise still in flyable condition. A spectator saw Blech's parachute descending with the pilot motionless in the harness. His neck was broken from undetermined reasons. His death might have been caused by hypoxia, since his barograph was found to have gone off its scale at its 25000 ft. limit.!
Heinz Scheidhauer's aircraft and parachute came down near Wustensachsen. He had bailed out after hailstones splintered his Plexiglas enclosure as well as the plywood covering, and was found unconscious, hanging in a tree. His barograph also showed an altitude in excess of 25000 feet, a height thought to be unreachable by sailplanes. Scheidhauer eventually recovered in a hospital, where he was treated for severe frost damage.
The Ho II with Hieckmann left the same cloud at 15000 feet, and landed safely 80 miles away. On the following day, he demonstrated the capabilities of his aircraft, both in ridge soaring and aerobatics before the public.
The Ho III, with its light wing loading and small turn radius, was well suited for both ridge and thermal soaring, and its stability and gentle behavior made it ideal for instrument flying. Still, the middle-effect problems continued to trouble us.
With the blessing of our Air Ministry, ten H III b's were started. Four of these appeared at the Wasserkuppe in 1939, where Scheidhauer made Gold-C distance, by flying over 200 miles.
Unfortunately, very little progress was made otherwise that year.