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Terminal Velocity

March11

A member of our club has a quote on their Facebook page about the ridiculousness of the name "terminal velocity". I can admittedly see what she means, in a skydiving sense especially one does not wish to hear the word terminal, let alone experience it. Nevertheless those scientists who originally discovered terminal velocity probably weren't thinking of it in this way, and thus the title was coined. Terminal velocity refers to the maximum speed an object reaches as it falls - were it not for our atmosphere everything would fall at exactly the same rate (there are cool videos of bowling balls falling alongside feathers in vacuum tubes) but the air resistance slows down things depending on surface area and mass. At a certain point during an object's acceleration the resistance will equal the force of gravity and it will remain at a constant speed, and a skydiver tends to experience this just before 12 seconds into free fall.

Saturday was a blustery day indeed and at points it felt like we may have the hangar rudely removed from around us - so of course there was no jumping. Regardless of this we spent the time wisely and spent many hours packing and unpacking parachutes. As students progressing through the sport the onus is on us to learn to pack, as there are only a limited number of freefall rigs available for use, and if many people have progressed to this stage there are times when the centre will run out. We learn by packing static line rigs, because fitting them in the container is easier and there's a little less that can go wrong with them. So it was that as the gales howled outside 5 of us knelt on mats folding pieces of material and untangling lines. The lessons are interesting from the point of view that we learn steadily more about the equipment, but do not make a good story. I will say that after packing a few rigs I finally got the hang of folding the tail of the canopy and shortly after managed to get one in the bag first time round. As a result the rigger (a very experienced packer who has spent years training and packs reserves) signed the rig off so that a student would actually be jumping it. It was exciting though also slightly unnerving and every possible thing I may have got wrong flashed through my head. We left with hopes of the wind going somewhere else to play on Sunday.

The wind went somewhere else to play on Sunday, or for the first half of the day at least. It was gratifying to see canopies descending as we drove near to the airfield, and we undertook our retrain with high hopes. My jump was to be another 10 second delay; every student has to do this one twice regardless of proficiency (and despite enjoying my last one I was far from stable). Soon after our training we were called to the flightline and got our gear on. As well as two of us on freefall there were 7 static line students - 4 of whom were from Durham doing their first jump. I noticed (despite attempting to avoid it) that one of the girls from Newcastle was wearing the rig I'd packed on Saturday but set my mind on my jump. We got into the plane, did a few passes at 3,500 feet to let the two static line students out, then headed up to 5,000 so that Nick (instructor and DUFFC Vice-President) and I could jump. We got to altitude (with the door surprising me by springing open on its own as we neared our exit point), the pilot throttled down and I climbed onto the step.

As I heard the word go a gust of wind hit me and my foot slipped the extra inch required to take it off the step. With this development unexpected by the rest of my body I fell rather ungracefully from the step, hitting my arm on it as I plummeted. This exit caused me to end up on my back, but I arched hard and managed to get back on my front. Despite being in this position I was still rocking all over the place and though I didn't go over again I wasn't in the best position. I kept my head up and kept my count steady though, and as I was reaching for the pull the yellow shape of my instructor appeared at the top of my vision, moving closer as I pulled my ripcord. The moment I pulled of course he appeared to shoot downwards as I was decelerated by the opening of my canopy. Once I'd checked that it was a good canopy I looked below and could see him under canopy about 1,000 feet beneath me. From that height it appears that other canopies are far lower than they actually are - indeed I thought he was going to hit the ground when I first looked. I had a fun ride down, the wind wasn't very strong and I executed my landing pattern well, landing just to the near side of the accuracy circle. After being debriefed, progressed to 15 second freefall and nursing my arm I was told by one of the static line students that the CCI had been shouting on the radio for me to turn at various points, before being told I didn't have a radio. Soon after I watched the girls' plane drop and was hugely elated to see the canopy that I had packed open without a hitch. I told the girl afterwards - she said she was glad I hadn't told her it was my first student pack job before she jumped.

The second jump came later in the day, as we had to wait for another pilot to arrive. We got into the plane and despite the door flying open and being very difficult to shut we dropped a static line student without issue. My friend Lucy was next to jump, 10s from 5,000 feet and it was getting quite cloudy at this point. We made it over the spot and it was clear to the ground, so she jumped and all was fine. As we continued upwards, however, the cloud became steadily thicker until all around was white. I was nervous at this point but knew that if it was safe to jump then I'd still go. Unfortunately the pilot called it and brought the plane back down to the ground - my first land in and it wasn't too bad, if a bit odd. It seemed like I'd have to wait a bit longer for that terminal velocity but the instructor Lee was approaching the plane with another 15s student and above us the sky had cleared again. We followed the Airvan into the sky and had quite a relaxed ride up. As we got to altitude I was gazing at the clouds around us, an absolutely magnificent sea of white stretching to a blue horizon, drenched in the sun as it began its own descent through the sky. Large pillars and bulges at points indicated the rain to come, but I can't remember seeing many more majestic sights. The first student jumped and then it was my turn.

As I jumped I once again ended up on my back, a problem which I have to solve next time round. I flailed for a few seconds but then I tried the technique Nick had told me, clicking my heels to "reset" my legs, making each aware of the other's position. Trying a few times I was suddenly completely stable - falling flat, or more particularly flying as I was no longer accelerating towards the ground; I had hit terminal velocity. It was an almost surreal feeling - distinctly aware of the motion due to the 120mph winds hitting me from beneath, but not feeling the drop at all. I reached 14 seconds on the count and went for my deployment handle - once more staying steady in the airflow. For the first time I didn't fly everywhere on deployment - it was a good two seconds more of falling flat before the canopy opened and I sprung upright. I was so exhilarated that I shouted into the air. My ride down is another story, and I shall tell it separately, but the jump was the most spectacular yet.

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“Terminal Velocity”




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