Two failures of "slider" harnesses in Los Angeles, different in cause but similar in effect, illustrate an unexpected consequence: the backup straps may leave you hanging too low to control the glider.
In July , 2006, Larry Chamblee, flying a Woody Valley harness with a rope "slider," found himself hanging by his armpits from the speedbar after his main support chafed through. His account of the cause, his wild ride and eventual decision to deploy his parachute makes good reading, here: http://shga.com/forum/phpBB2/viewtopic.php?t=276
In 2005, George Stebbins suffered a sudden failure of the slider bar in a Rotor harness, which also left him hanging too low to fly with adequate control. See "Stebbins Harness Failure Report" thread.
If you fly a slider harness, what happens if the slider fails? Can you fly the glider from the backup straps? How strong are the backups, and how does that effect a decision to deploy?
"Slider" Harness Failures
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SHGA Communications
- Posts: 106
- Joined: Sat Jul 15, 2006 11:20 am
- Location: Hang Gliding Capital of the World
My Harness Failure
An important factor in my decision to throw my chute was that, in the stressful moment I did not remember several important things.
1. There is a backup to the main suspension system, a slightly longer hang strap that will support all your weight, but leaves you hanging so low that you lose much of your pitch control. Both George Stebbins and I found ourselves going way too fast to land safely.
Because I didn't realize that I could hang from my harness, and consequently kept hanging on the control bar by my armpits, the control bar was aft of trim, the glider's angle of attack was low, and I was going really fast. I might have had more options if I had realized that I could relax my death grip on the control bar and hang from the harness backup strap. Then I could have determined if I had any pitch control.
I have since determined that my backup strap was far too long, and have shortened it so that I will be hanging only a couple of inches low if the main suspension were to fail.
2. You can fly the glider by standing in the control frame. I've seen pilots do it several times. But I'd never tried it, and I have no idea how to cllimb up into the control frame. But I am going to find some smooth air at a nice high altitude and try it a few times.
Dennis Pagen sent me an email asking me why my accident report failed to mention the "eyebolts" that are essential in my model Woody Valley harness to prevent the slider rope in the main suspension rig from fraying and breaking. My harness has never had any eyebolts, and I didn't know it was supposed to have them. I bought it used, and never sought any guidance from the manufacturer or anyone else about what parts it ought to have.
I think that, from now on, if I buy a piece of used equipment, I will either get the owner's manual or get in touch with the manufacturer or a professional to get all the information I can about the equipment.
Mr. Dumb Luck
1. There is a backup to the main suspension system, a slightly longer hang strap that will support all your weight, but leaves you hanging so low that you lose much of your pitch control. Both George Stebbins and I found ourselves going way too fast to land safely.
Because I didn't realize that I could hang from my harness, and consequently kept hanging on the control bar by my armpits, the control bar was aft of trim, the glider's angle of attack was low, and I was going really fast. I might have had more options if I had realized that I could relax my death grip on the control bar and hang from the harness backup strap. Then I could have determined if I had any pitch control.
I have since determined that my backup strap was far too long, and have shortened it so that I will be hanging only a couple of inches low if the main suspension were to fail.
2. You can fly the glider by standing in the control frame. I've seen pilots do it several times. But I'd never tried it, and I have no idea how to cllimb up into the control frame. But I am going to find some smooth air at a nice high altitude and try it a few times.
Dennis Pagen sent me an email asking me why my accident report failed to mention the "eyebolts" that are essential in my model Woody Valley harness to prevent the slider rope in the main suspension rig from fraying and breaking. My harness has never had any eyebolts, and I didn't know it was supposed to have them. I bought it used, and never sought any guidance from the manufacturer or anyone else about what parts it ought to have.
I think that, from now on, if I buy a piece of used equipment, I will either get the owner's manual or get in touch with the manufacturer or a professional to get all the information I can about the equipment.
Mr. Dumb Luck
Soar With Prudent Passion
Larry Chamblee
Larry Chamblee
A few comments on what Larry had to say:
My harness backups were too long to even think about climbing into the control frame. The basetube was at my forehead when I was hanging vertically. From that position if you try and do anything asymetrically (like climbine up) you are doing an instant wingover. If your backup is too long but only by a little bit, then climbing up makes sense, and Larry's suggestion to try it high in smooth air also makes sense. I didn't have that option. By the way, I have climbed into the control frame before to fix a "things falling out of my harness" situation. It takes more altitude and causes more roll input than I would have thought. I assume that with practice that changes, but the first time you are likely to be surprised by the diving and rolling.
Larry says that now if he had a main failure he would only be hanging a couple of inches too low. That is great. I have (through my own mistake) had to fly a glider with a main that was 3 inches too long. It flew fine, I just had to fly partly upright to keep my chest off of the basetube. So, if you get your harness set so that the backups are only a few (up to 5 or 6? ) inches too long, you are probably fine. Mine was about 2 feet too long. At that length, your "fully pushed out" speed would be about 35 or 40 miles per hour on a topless glider. That's what my track log says, anyway. (Call it 1 1/2 times stall speed or so?) If you have shorter arms than me, then it would be even faster. That's way too fast to land safely without a seriously padded LZ. The only reason I didn't throw my chute is that the harness straps looked damaged from my position, and I was concerned that a chute deployment would break it. Then I would have been detached from both the chute and the glider. I felt that I had no choice except to find somewhere to land and do the best that I could. Besides, like Larry, I didn't realize at that point just how fast I was really going. Larry, with the benefit of my experience and the knowledge that he had about why his failure occured was pretty darned certain that he could safely deploy. I'm glad that my experience helped him.
Here is the link to my original article on my harness failure: http://ozreport.com/pub/rotorfailure.shtml
Here is the link to the Wills Wing follow-up article: http://ozreport.com/pub/rotorfailure.shtml
Thanks for your article and your brutally honest self-assessment, Larry! That kind of attitude helps others to fly more safely.
Sign me - Even Luckier Than Larry
My harness backups were too long to even think about climbing into the control frame. The basetube was at my forehead when I was hanging vertically. From that position if you try and do anything asymetrically (like climbine up) you are doing an instant wingover. If your backup is too long but only by a little bit, then climbing up makes sense, and Larry's suggestion to try it high in smooth air also makes sense. I didn't have that option. By the way, I have climbed into the control frame before to fix a "things falling out of my harness" situation. It takes more altitude and causes more roll input than I would have thought. I assume that with practice that changes, but the first time you are likely to be surprised by the diving and rolling.
Larry says that now if he had a main failure he would only be hanging a couple of inches too low. That is great. I have (through my own mistake) had to fly a glider with a main that was 3 inches too long. It flew fine, I just had to fly partly upright to keep my chest off of the basetube. So, if you get your harness set so that the backups are only a few (up to 5 or 6? ) inches too long, you are probably fine. Mine was about 2 feet too long. At that length, your "fully pushed out" speed would be about 35 or 40 miles per hour on a topless glider. That's what my track log says, anyway. (Call it 1 1/2 times stall speed or so?) If you have shorter arms than me, then it would be even faster. That's way too fast to land safely without a seriously padded LZ. The only reason I didn't throw my chute is that the harness straps looked damaged from my position, and I was concerned that a chute deployment would break it. Then I would have been detached from both the chute and the glider. I felt that I had no choice except to find somewhere to land and do the best that I could. Besides, like Larry, I didn't realize at that point just how fast I was really going. Larry, with the benefit of my experience and the knowledge that he had about why his failure occured was pretty darned certain that he could safely deploy. I'm glad that my experience helped him.
Here is the link to my original article on my harness failure: http://ozreport.com/pub/rotorfailure.shtml
Here is the link to the Wills Wing follow-up article: http://ozreport.com/pub/rotorfailure.shtml
Thanks for your article and your brutally honest self-assessment, Larry! That kind of attitude helps others to fly more safely.
Sign me - Even Luckier Than Larry
Fly High; Fly Far; Fly Safe -- George