Oct 1, 2001, 9:32 AM
Post #1 of 9
We had a situation this weekend at the dropzone where a quite-experienced birdman flyer, Bobby Pritchard, had a serious problem. Bottom-line up front: he lived and landed safely under his reserve, but lost his freebag.
Bobby is a light guy, maybe 130 pounds and owns an older BirdMan Classic. He he has sustained vertical speeds as slow as 30 MPH. Anyway, he threw out this time and had a baglock. No real reason for it, but the last bit of locking stow just didn't come out. He collapsed his wings and then pulled his cutaway without any problem, but the damn risers would not separate! It seems that there was not enough drag on the 3-rings to force them to release! Bobby stayed "collapsed" and built up speed until he reached his "now or never" altitude (1000 feet) and went to pull his reserve. Lucky for him, the risers separated just as he was doing this, so his reserve found clean air. He ended up landing three miles from the DZ right outside of downtown Raeford. The winds were honking this weekend, so I count him lucky for finding his main.
This is the second time that he has had a baglock jumping his wingsuit. I told him that I were him, I would immediately put a bigger pilot chute on that rig to increase his odds of successful deployment. I also said that I would make sure the line stows are not too tight when making wing-suit jumps in the future.
I am not sure how many others out there have jumped wing suits; I have, and it's a complete joy. This incident reinforces the need to continue beginning your opening sequence higher than normal skydives, even after you are thoroughly proficient at BirdMan flight. The equipment clearly adds another factor to parachute deployments, as well as increasing the amount of time it takes to deal with certain malfunctions. All I ask is that you read this note and ask yourself if you have experienced slower deployments as a result of your lower vertical airspeed. If so, then consider putting on a larger pilot chute.
Geoff, I think it is a 24" ZP kill-line; almost certainly a monkey fist, though I will have to double check to see the exact diameter. I know that one mod that some of those guys are doing is making a longer bridle. Wings is making a rig that allows the great majority of the bottom panel to flip down on opening. This, because in BirdMan flight you are going faster forward than you are down and in a typical configuration you pilot chute is trying to pull your bag straight backwards only to be held up my the solid corner of the bottom of the container. This certainly can lead to a pilot chute in tow and then a subsequent baglock due to insufficient snatch force if you do not "sit up" at pull time. The way I was instructed and deployed on my maiden flight was from the full track mode, just clicking your heels as you bring both hands in then back out at the pull. Watch any video of someone deploying in that standard method and you will see the PC and bridle stream out straight behind them until the bag yanks up, then clear of the trailing edge of the container. If that first yank (at full bridle extension) isn't sufficient to pull the bag "around the corner", then you are hosed until you can better align the extended bridle with the container opening.
Fix it one of two ways: either with a bigger pilot chute, which might drastically change your openings on those jumps where you are not using the suit; or modify your rig in order to facilitate the bag being able to be extracted more to the rear than the front.
Personally, if I owned my own BirdMan suit, I would go ahead and modify the bottom panel/side panel junction of my container, leaving only the bottom two inches bartacked to maintain the integrity of the container shape. Unless I am not remembering correctly, the Voodoo container comes stock kind of like that. I know I heard this weekend that Wings was doing exactly that as a factory option. As these suits gain popularity, then so should the container manufacturers offer ideal, yet simple options in order to facilitate safer flights.
Personally, if I owned my own BirdMan suit, I would go ahead and modify the bottom panel/side panel junction of my container, leaving only the bottom two inches bartacked to maintain the integrity of the container shape. Unless I am not remembering correctly, the Voodoo container comes stock kind of like that. I know I heard this weekend that Wings was doing exactly that as a factory option.
Although I have not seen it in writing anywhere, Mirage also offers this as an option.. When I ordered my Mirage a few weeks ago, when Bill Hallet found out that I will be using it for BirdMan jumps, he told me about that mod(no extra cost).. I had it done to my rig.. I will get video of my deployment with a BirdMan suit, and if it is at all questionable, I will lengthen the bridle a few feet..
One of the BirdMan instructors told me that they are currently working with Sunpath to put together a similar setup for their containers.
i do believe in the right equipment for every job.
if you are into a specialized dicipline as wingsuit flying, you should have specialized equipment for the task. ie, larger pilot/longer bridal/track deployable container.
body position is also very important. i have heard many different techniques for deployment body position on wing suits. what works for me was taught to me by robert (birdman designer) and stane (atair founder) while learning to fly my skyflyer in slovenia: track like a bat out of hell, shoulders and elbows rolled foward, forearms almost parallel to your body, palms facing out away from your body, no arch, knees almost straight, toes dug in, head looking down not foward. in this position you will travel very fast foward and create the slowest possible vertical speed. when it is time to dump (for me that is a high 4-5k) i first apply the brakes by bending my knees, momentarily bleed off a little excess foward speed and then transition immediately back to the full foward track position, then close all wings and throw the pilot. do not deploy in an arch. when you close your wings to deploy your body should not change position.
this is tricky and takes some practice and awareness. by dumping in a proper full track the pilot is deployed into clean air. when you arch to slow down, even if you are still tracking foward, you are effectively in a stall, your pilot goes into separated turbulent flow with unpredictable results.