MID-AIR LINE FAILURE

Author: Arthur Gemperle

I am an experienced pilot with 1010 flights and 760 hours airtime. I had been flying a 2 year old (second hand) Apco Zen 2 for 1 year, which had 290 hours usage.

I took off by myself around 4.30pm and was soon joined by about another 10 pilots. We were flying at Bulwer in fantastic valley release. After 1 hour of working gentle lift I had climbed to 1900m above the Bulwer town. The lift had been very smooth - perfect student conditions.

The Sun had set and it was time to top-land before it got dark. I thought a good controlled spiral would finish off the day nicely. I went into the spiral and when I reached 12m/sec something horrible went wrong. I heard a sound like a tree branch cracking. I looked up and saw my lines snapping in a quick chain reaction. It took 1 second; and 50% of my middle cascade lines were gone. I then heard a tearing noise. I started going into free-fall. I could see the glider had torn apart. I checked my height and I was still 1800m AGL. There was a gentle breeze up the face of the mountain and I realised if I threw my reserve immediately; I would drift over the back of the peaks and be landing somewhere unpleasant in the dark. Therefore, I decided to not throw my reserve as yet, much to the astonishment of the other pilots. My radio was screaming from the other pilots shouting "Throw! Throw it!!!" I calmly replied I was far too high and every thing was under control. My descent rate was stable at approximately -22m/sec down (80km/hour) and I had my hand on my reserve handle.

After a straight fall of 1000m (which took about 45 seconds) I decided to throw. I was now 800m AGL. I pulled and threw it outwards. At that speed the reserve shot upwards, straight into my flapping canopy. The reserve didn't open immediately and forced its way into my canopy. It then started opening and proceeded to tear my already ripped canopy into 2 separate pieces. The reserve opened fully and my sink rate dropped to a pleasant 4-5m/second. I fly with a Tandem reserve as I do lots of Tandem flying.

The glider was loose in 2 separate pieces, so I pulled them in towards me. I was amazed how stable my descent rate was. I was drifting slowing back towards the mountain. After a pleasant 2 minutes I landed with a gentle roll on the slope at the base of the mountain. I didn't even have a scratch on me.

The rescue party arrived in a cloud of dust, but I informed them I was OK.

On inspection of the glider we found that 50% of the middle cascades of the A's, B's and C's were broken. Some were broken in the middle and others at the stitching points. On the smaller part of the 2 pieces of wing, all the brake-line attachment-points had been ripped out from the glider's fabric. None of the main long-lines had failed, which are the lines that are normally changed when doing line-maintenance. We should be aware that all lines need to be changed and it is in my opinion this should be done between 200 - 300 hours, depending on how hard you fly the glider. I had flown this glider under very strong conditions and had done many SIV maneuvers and induced collapses.

Arthur Gemperle