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Unsuccessful reserve deployment / Walts Point
This report was originally submitted to the USHGA in confidence for statistical evaluation only. The report is now offered for review by our flying community so they may learn from my mistakes.
Date of Incident
About 10 AM, Mid Summer. Winds aloft over the back from the west about 15 kt. Up slope convection starting to overpower the morning catabatic flow on faces with good sun exposure.
Waltís Point, 9,000í launch on the east side of the Serra Nevada Mountains near the town of Lone Pine CA, just south of the Owens Valley.
A seasoned P4 pilot with recent experience in strong conditions.
Edel Sector, Large, ACPUL Competition, DHV 2-3, Ballasted to a gross weight of 110 Kg, slightly over the published maximum gross weight of 105 Kg.
Harness and Gear
Edel Pro-Lite harness, adjusted loose. 12 cm Supí Air back protector, plus a 10 liter MSR ballast bag underneath filled to capacity (22 lb.), plus an additional 2.5 liters of water stored elsewhere in the equipment. Multiple bulky clothing layers and capilene glove liners (additional high altitude gloves stowed in belly pack). Protec open face plastic helmet.
The pilot was first off on a crowded day and had a beautiful reverse launch from below the lip into smooth up slope convection. The pilot climbed a couple of hundred over in the smooth buoyant air and relaxed mentally feeling confident and elated. He then went to the saddle to core up but had to get on the speed bar to penetrate upwind against catabatic flow to reach the saddle. The pilot searched the saddle for a convergence thermal and tried one loosing 360 in questionable lift. Down to tree top level the aircraft fell off with the catabatic flow and the pilot had to run out the center of the canyon. Glide was downwind (10 + mph catabatic flow) in smooth sinking air. The pilot considered speeding the glider up due to the sink but decided the to fly brakes off unaccelerated due to the significant tailwind and potential for turbulence. About 10 seconds into the glide with about 500í of terrain clearance the aircraft hit the up slope flow. The resulting increase in airspeed tucked the glider violently and the canopy fell back past horizontal (115 degrees?). The glider came overhead and was momentarily stabilized with the left half tied in a cravatte. The pilot tried one pump in an attempt to clear the cravatte but the wing broke into a flat spin and twisted the lines as the canopy helicoptered above. Having lost confidence that he could regain control in time the pilot elected to deploy. The loose harness was tilted substantially to the left away for the deployment handle on the right side which was not visible. The pilot made a sweeping pass forward with his arm searching for the deployment handle. The pilot was a shocked when he did not locate the handle and frantically made several back and forth passes with his arm searching for the handle. The pilot then pulled himself uphill in the harness with both arms to look over the side and made visual contact with the handle. He deployed with one motion outwards and watched the canopy quickly go to full stretch off to the right. He then glance down to the left to access his time remaining and quickly glance back to the right to access the deployment progress. The canopy was still laid out horizontal and fully stretched. It was apparent that the canopy would not fill in time to slow the decent.
The glider was in a parachutal flat spiral to the left with just a tad of forward speed. Vertical decent was probably about 45 feet per second. The terrain was an ominous mix of trees, scrub, boulders, and pulverized granite on a slope of about 45 degrees. With about 2 seconds left the pilot began to prepared for impact. He garbed the harness webbing on each side and forced himself into and level upright position with feet together. Passing tree top level ground rush was faster than sensory perception and the pilot impacted with a thud sooner than expected. He hit facing up slope with minimal forward speed and collapsed through his legs to a seated position. He was in the shade of some trees on pulverized granite next to some large boulders. He took a few moments to catch his breath and radioed to launch that he was OK but had injured his back. He eased around to face down hill, laid back to rest and slowly began to loosen his clothing. Assistance arrived in about 7 or 8 minutes.
The glider was loaded heavy making it faster and more solid for the expected ride but the additional speed left it venerable to wicked front tucks. The glider was rated DHV 2-3 within itís placarded weight range, but the same model one size smaller was rated DHV 3. The gliders true airspeed was probably higher than the certification testing speeds due to the heavy loading and thin air at density altitude. With a pressure altitude of about 9,000í and an air temperature of about 25 C the density altitude would be about 12,000í. The air is about 35% thinner and resulting true airspeeds about 20% higher than sea level speeds at standard temperature. The higher operating speeds result in the potential for higher rotational momentum to develop as a result of a violent full frontal tuck. The glider probably would have been rated DHV 3 if tested at the density altitude and wing loading flown. The sudden increase in airspeed passing through the wind sheer into the up slope flow left the glider with excessive airspeed and venerable to excessive rotation as the light balled up canopy slowed radically in the airflow and the heavy pilot continued forward. Due to the extra rotational momentum the package was able to rotate more than 90 degrees causing the lines to go slack as the pilot fell backward from above the canopy. The slack lines and balled up canopy increased the potential for a large cravatte.
The pilots decision to deploy was probably a good one but his inability to quickly find the handle used up too much irreplaceable time. There were several factors resulting in the inadequate pilot performance in locating the deployment handle. The pilot regularly flew various equipment which left him less certain than someone dialed into just one personal setup. The pilot was wearing more clothing layers on his arms than usual reducing his sense of touch. The loose harness resulted in more effective pilot weight shift but left the harness hanging steeply to one side away from the deployment handle when supported by only one riser. Because the pilot was shifted to the left he was overcompensating on his sweeping reach for the handle thinking he would be able to feel it with his arm if he overextended. The pilot performance in climbing uphill to visually see the handle was good and the deployment was fast to line stretch due to centrifugal force as a result of the slow spiral. The canopy was slow to inflate once reaching full stretch because it was laid out horizontal and was falling at a speed near the same speed as the rest of the package. Air was not entering the air channel of the flaked canopy effectively in the direction it was traveling. One could argue that the pilot should have pumped the canopy to get some air into it which would slow it down and bring it overhead quicker, however, the rapidly approaching ground and imminent impact also tends to demand attention.
The pilot hit feet first but due to accelerating ground rush he lost perception, hit sooner than expected, and collapsed through his legs to a seated position upon impact. The pilot had a good back protector and the water ballast bag underneath probably helped dampen the deceleration. Although the ballast bag added to the back protection it also added to the weight of impact. It was not then, but is now, my opinion that when impacting with water ballast the extra force of impact is not worth the extra protection from the water. The legs can absorb more impact if they donít have to catch the extra 20 pounds of weight.
The pilots performance in preparing for impact was pretty good but he could have tensioned his legs to compensate for the impending loss of timing perception.
The pilot was lucky that his immediate impact site was pulverized granite as there were nasty possibilities within reach.
Obvious Primary Cause
The pilots laxing focus after a sweet launch followed by an easy initial ride in smooth air resulted in decision by habit rather than intuitively reading the conditions as they were. The pilot continued to drive into the catabatic flow toward a potential thermal source despite the deteriorating predicament because he had always had success there before. The pilot should have fallen off into the up slope flow sooner and run for the point if necessary. His lax focus for the level of hazard left him in a precarious position at tree top level over a saddle having to run out a canyon downwind in the lee of the saddle.
The pilots inability to quickly locate the deployment handle resulted in an ineffective deployment.
Speculative Contributing Cause
There are several factors that resulted in improper focus. Additionally, the pilot had never encountered such a violent gyration and didnít have a preconceived understanding of how the aircraft was going to behave. A better trained pilot might have been able to regain control of the aircraft within the available time.
The wreckage was about 700í vertical below launch. It took awhile for the first volunteer to reach the site. The pilot had radio contact with the launch director. He indicated that he was stable and relatively OK but had compressed his back. The pilot indicated that although he could stand, he could not walk out. The launch director called for an ambulance from Lone Pine. Search & Rescue was also notified but their ETA was excessive. The rescue team had to wait for the ambulance to arrive. One of the ambulance paramedics brought the backboard down along with oxygen but he became heat stroked and nauseous in his fire suit. He had to use the oxygen for himself and needed assistance getting back up the hill.
The pilot was strapped to the backboard and hauled up the steep slope by many volunteer hang glider pilots who gave up their vacation day of flying to come to the injured pilots assistance. The trip uphill was brutal in the heat and thin air at a density altitude of about 13,000í. The slope was steep and the footing mushy in the deep pulverized granite. The haulers were exhausted and had to change shifts every 30 feet. It took about 3 hours from impact to Lone Pine Hospital.
Possible compression fracture of the L1 vertebrae, and a strained back. The pilot was released for Lone Pine Hospital that afternoon. An infected appendix a couple of weeks later likely resulted from constipation due to the back strain. The infected appendix was not diagnosed on a visit to the primary care physician complaining of nausea and abdominal pain so it progressed and ruptured resulting in surgery followed by an agonizing hospital stay.
A year latter recovery seems to be complete, however there is still some back ache when standing up after being stooped over.
Primary Lessons Learned
© copyright 12/2/98
Published on 2/23/04