A decade of research by
Gliding Expedition to the Jungfraujoch
Groenhoffs own report from his book "Ich fliege mit und ohne Motor"
My thunderstorm flight to Kaaden had created interest all over the world. So I was invited with my "Fafnir" to an air show in Basel. This gave us the idea to combine it with a previously proposed Alpine gliding expedition. The initial preparations had already been done by Basel.
The Jungfraujoch seemed to us to be the most appropriate place and good starting point for the expedition. The Directorate of Jungfrau region, which leads to the Joch readily promised every possible assistance. Four men took part in the expedition.. A technical manager, engineer Riede!, a scientific director, engineer Hardt, and the aircraft fitter William besides myself. With the "Fafnir" fastened to a rail car along with tools, tarpaulins and Start ropes we made our way to Basel. On Saturday night our engined support aircraft, the "Flamingo", landed in Basel, at precisely the time the transport train rolled in with the "Fafnir" for airplane hangarage. The airfield is located in Basel on the Rhine. Directly opposite is a beautiful mountain. In towed flight Riedel tows me several times to 1000 meters and then I try to display the glider to the audience . I spent twenty minutes at thie nearby hill, then in a couple of elegant curves I flew the "Fafnir" before them and then landed to the amazement of spectators on the skid, just in front of their eyes. That evening we packed the "Fafnir" with everything, then set off in the direction of Lauterbrunnen. In Lauterbrunnen we must load onto the mountain railway. It was not without difficulties. The fuselage and wings had to be put on two separate cars to avoid being stuck on the bends in the tunnels.
When I saw the peaks so close to me for the first time, they made a powerful impression. The high summits lay wonderfully clearly before us where little ragged clouds hung everywhere. The great white snow fields differentiated themselves sharply from the sky. One pointed for me: up there in the trough of the steep slope is the Jungfraujoch. By train it is always higher. The vegetation diminishes, only the highest alpine flowers stand on the meadows and then, after the Eiger glacier station, the rack railway disappears in the eleven kilometer long tunnel. After a one hour journey we arrive at the Jungfraujoch station.But how do we get from here? The tunnel of the road ends in the rock and has only one exit to the Hotel Jungfraujoch. After la lot of trying out and measuring we find that the parts can be transported via the hotel balcony. There, they are roped and carried up to the Jungfraujoch along precipitous slopes by skilful guides. A good head for heights is necessary. All our efforts were of great interest to the elegant visitors with whom one heard all languages of the world. Protected from the wind, in a snow pit, the "Fafnir" slowly took shape. The very next morning it was ready to go. The weather was excellent, only the wind was 13 to 19 M/sec. and violent turbulence was a bit too strong.
Perhaps 100 meters away from the cliff, I made the "Fafnir" ready to go. The supporters of the Jungfrau train were shown their positions that they should take at the start and explained. "Launching" was not easy for the people, because in the snow-covered glacier fissures one could easily get caught. Riedel took over the starting squad. Because of the cold it was so thickly packed. I could barely even fit into the narrow "Fafnir" fuselage. Idi give the signal "Ready". At the command "Stretch" the Start leader begins moving and stretching the rubber cord. All wanted to run and give their utmost power, but suddenly the frozen "Falnir" snatches off from the snow. For the retaining crew the jerk is not expected. The "Fafnir pulls too soon out of the hands and toboggans with great speed, but not fast enough to be able to fly, to the edge of the cliff. The starting team throw themselves flat on the floor and I sweep away close by them over their heads. There is no more turning back. The fuselage nose hits a crusted snowdrift that breaks the plywood and at the same moment, tipping the machine over the slope edge and falls into the depths. Despite a high speed, the elevator control does not respond. It can be difficult to persuade oneself it must be broken or damaged. After about 100 meters dive the machine recovers by itself. I try once more to fly, but again it falls on its' nose, falling another 80 meters and starts again. With the rudder I manage to get the "Fafnir" away from the nearby rocks. I unable to explain what has happened. With my small windows I could not put out my head very far to allow me to see the back.
I surrender myself to my fate, fly in the direction of Interlaken, and make up my mind to jump out at least 500 meters in height with a parachute. I lose my height like on a staircase. In all possible flight attitudes I try to get the "Fafnir" a little bit more controllable, but totally without success. The altimeter gets ever closer to 500 . I have a look at the wind and calculate the place where I must jump out to land in a small, clear place. I hold the canopy and take in hand the Leika ready to take pictures of the last flight of the "Fafnir". 500 is reached, but as I went to open the canopy, I could not allow myself to do it. To simply leave the proven "Fafnir" and surrender it, is difficult for me. I think of the Kaadener flight and of the coming Rhön competition with which I urgently needed it.
At 300 meters I can still jump out. Again, I try everything. Once, when the "Fafnir" was upside down, I gave full Right on the controls. It stood on its head and began to whistle with the increasing speed. Slowly I gave elevator control, until I realise that wants to do its own thing. With well over 100 kilometers airspeed, I am in a steep glide with the ground rapidly approaching. Now I must decide, either it stays in control or there will be failure. The ground comes up, I skip a few trees, and when I want the machine to fly horizontally above the ground she bends her head back by itself, crashes to the ground and turns by 90 degrees and slides sideways for maybe 20 meters through the meter tall grass. Smooth landing!
It took me 58 minutes from Jungfraujoch to the landing, enough time to get grey hair. Down here it is disgustingly hot, especially in my thick clothing. I get out and look and to my surprise, half the tailplane is missing . I take off my flight clothes and lie down for a moment in the cool grass to rest for a while. From a spectator I borrow a bicycle and then rides fast as I can to the nearest phone. I can tell the joy from my people when they know that I am well. I immediately spoke with the Wasserkuppe and order a new elevator. In the afternoon my crew arrived with a trolley and we brought the bird back on the path to the Jungfraujoch. In the evening we sit together and celebrate my birthday. It must have been at least as bad for the viewers watching this false start as it was for me. I was told they saw a a hole the shape of the Fafnir fuselage in the high snowdrift created as the glider slid through. Luckily it was only half the elevator which fell with the machine over the slope edge away into the depths. The helpers had stood rigid, waiting for the noise of the impact, but like a miracle I appeared, even if at sometimes in strange flight positions, in their field of vision.
After two days the replacement tailplane arrived on the Jungfraujoch and the "Fafnir" was ready to go again. lt was an interesting flight, sailing back and forth on the steep slope of the Jungfraujoch. A wonderful picture. Below me was the great Guggigletscher and at the foot of the Eiger glacier station, perched on a projecting rocky cliff above, the lonely Guggihütte. At 2000 meters altitude, the sea of clouds begins to bring bad weather. In the evening, the "Fafnir" was dug completely into the snow so that a suddenly emerging storm would do no harm. In the morning we dig it back out of its' cave and leave it to dry in the sun. After a few days the weather is again suitable for a new launch. We start to the north as in the first two flights.
"Stretch .. .. . Run " ----- but just as the command "Go" was to come there is a crash. The two pedals of the rudder, on which my feet work move forwards and the "Fafnir" leaps into the air. With a defect, I want to throw the machine into the snow, but I realise the elevator control still works. The rudder is out of service. It is difficult to fly, so to speak, but much easier than with unusable elevators. I sometimes got into critical situations, but after an hour I land back on my airfield in Interlaken. l jump angrily from the machine because of this new incident and see that the rudder is torn from its hinges and was just hanging on the control cables looking like a pusher propeller behind the machine. As my companions later told me, a big block of wood tore out of the fuselage to which the restraining rope was fastened. Unfortunately the block also held the rudder hinge and that was pulled off as well.
Dissappointed with our bad luck, we discussed what we should do now. We found that this failure could just as well have happened on the Wasserkuppe. During that night and the next day the damage was repaired and the "Fafnir" was made ready for a new launch. Since our financial resources had become scarce, we accepted an invitation to do an ait display in Bern to help pay for a few more days.I had to have some luck once sometime. I promised, on Saturday afternoon, to fly the "Fafnir" from the Jungfraujoch to land at Bern. On Saturday morning there was a southerly wind and thick cloud. When it was time to start, I went to look again at the weather in the Joch. The cloud cover had dissipated and between the patches of fog I looked through to the clear blue sky. ln the Jungfrau Hotel I quickly got everything ready to prepare the "Fafnir" for the slope. All helpers have already become professionals. The launch works as well as on the Wasserkuppe. There is southerly wind and I fly through a few wisps of cloud and come out in a strong descent falling four to six meters per second. The downdraft zone is very narrow, but then in calm air I soon go further over the beautiful mountains. At high altitudes, I skim Interlaken, use the updraft on the slopes that rise from Lake Thun and come closer to the lowlands.Behind Thun I hang onto a cloud and am able to gain some height. As I sail along the lower slopes I see Bern and even further ahead, the airfield. 300 meters, I'm still high as I fly through the cheers. Everyone is running out, greeting me by waving and the start siren sounds for my reception.
We had gained a lot of experience, but the work was far from complete. We need several more attempts of this kind to clarify all the issues we have raised.