sundevil777 102 #1 March 1, 2003 Please correct me if I'm wrong, but doesn't the TSO allow a person to "help" their results when testing a container by using reserves known to open slowly (even rounds)? If true, then the load applied is not known, therefore proving nothing. I really hope this is not true. Wouldn't it make more sense for harnesses to be tested based on a certain load mechanically applied in an easily repeatable manner. The load could of course be a based on wanting to withstand a specified weight at a specified g-load, of couse simulated with a static load for a specified time.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
hookitt 1 #2 March 1, 2003 I'm looking for a link to show the Testing Blocks used in some TSO drop tests. Does Any one know if one is available? The block is a link placed in line with the riser used to test the G-force (shock or point loading) of a Drop test. Unfortunately I forget the name of it. In No way were the Figures "helped" by a slow opening Parachute in the tests I've seen. There's no point in that. The parachute is packed like the one you wear on your back. The coolest test was done after the TSO test was complete. Imagine when the rig designer and the parachute designer decide to see if they can cause catastrophic failure to the Equipment. "Hey Fred?" "Yes Slim?" "Lets see if we can destroy this rig *HiyUck Hyuck!*" huh huh Huh huh huh So off they go and fill the Test dummy up with Extra weight and skim 500 feet above the Willing farmers field at over 200 knots. Big Grin from the Ground crew and a Nervous Laughter coming from the person who has to push the dummy off the rollers out of the plane. "Lets Do it" *Hyuck*! Diggety, lets wreck sumthin"! SO the ultra heavy dummy is static lined out of the plane and What do you know.. the damn parachute system didn't break The final Test on the Icarus Tandem reserve was with a 900 pound dummy at over 200 hundred Knots. It took it!My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto Quote Share this post Link to post Share on other sites
sundevil777 102 #3 March 1, 2003 What I want to confirm is what the test procedure is for the harness container system-not the reserve. Is it subjected to a static/ground loading test AND dummy drop tests? Or is it dummy drop tests only? CliffPeople are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
riggerrob 644 #4 March 1, 2003 All the tests on the reserve canopy and harness are done by dropping them out of airplanes. Yes, theoretically you could test harnesses on the ground with a fancy tensiometer. Unfortunately SAE and PIA have never convinced the FAA that this is a good idea. Some of the drop tests (under TSO C23D) are done with recording "load cells" sewn onto the reserve risers. These load cells record time and g-force during opening shock. There is not much point to cheating by substituting soft opening canopies during test drops. The FAA has a rough idea what to expect in terms of opening times, g-loadings, etc. and will review the g-meter data to see if it resembles similar drop tests done by other manufacturers. Round reserves do not open softer! If you have ever studied round canopy deployments, you would know that rounds open in a snivel, snivel, snap sequence. The "snivel, snivel" portion is very difficult to predict, while the "snap" portion frequently exceeds g-load limits prescribed in TSO C23D. ONly the most recent generation of rounds with sliders open softly, but none of them are approved as skydiving reserves. Remember that all TSOed parachutes must demonstrate consistent openings at 254 pounds and 150 knots. TSO C23D gives manufacturers the option of TSOing parachutes to heavier weights and/or higher airspeeds. Quote Share this post Link to post Share on other sites
sundevil777 102 #5 March 1, 2003 All the trouble to require load cells but no objective standard? So the weight/speed standards prove nothing other than the ability to withstand a set of openings on the canopy of choice by the mfg? I just want to know what these ratings are actually proving.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
sundevil777 102 #6 March 2, 2003 Quote frequently exceeds g-load limits prescribed in TSO C23D. What g-load limits? Are the drop tests required to impart a minimum g-load. What is that load? Does it change for the heavier, higher speed tests? Either the test procedures actually require more load to be applied to the harness, or it just supposes that more load will likely be applied by subjecting it to the opening of a reserve with more load at higher speed. Either the procedure allows the use of slow opening canopies and allows packing methods to produce slow openings or it requires minimum g-load to be sustained for a minimum time. It appears that the standard does not allow one to make the conclusion that such rigs are stronger. Without knowing the old spec applied (for example) at least 250 lb at 8g for 30ms, versus the new spec applied at least 250 lb at 12g for 30ms, the spec is meaningless. Am I the only one who sees this? Or is there really some useful differenc in the test requirements to prove the harness has been subjected to more load? As I said before, I don't want to believe the tests are so inadequate, but it is starting to look that way.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
billbooth 10 #7 March 3, 2003 It is meaningless, and perhaps even dangerous to label a harness and container with a maximum weight and speed. The weight and speed a harness and container system can take depends entirely on the canopies (both main and reserve) which you put in it. It also depends on how symetrically the load is applied to the system. Let's say I drop test a PD 106 reserve in a Vector and it produces a max force of 2,500 lbs. Then let's say that PD drops the same type of canopy, and records a max. force of 2,600 lbs. Under TSO C23-d, the PD 106 would then not be legal in a Vector, even though it had been drop tested in a Vector. Now let's say I successfully drop canopy "X" (which opens very softly) in rig "A" at a certain weight and speed. This does not mean that canopy "Y" which opens twice as hard is safe at the same weight and speed, in rig "A", does it? This, and several other "problems" with TSO C23-d, is why we are now re-writing it. The only sensible marking to put on a harness is the is the force it can take before it breaks. In spite of that fact, TSO C23-d does requires a max weight and speed marking on harness and container systems. I'm glad I am TSO'ed under TSO C23-b, which simply requires a harness to pass a 5,000 shock load test. (By the way, Vectors have demonstrated much higher strength during drops from PD's instrumented drop test tower.) Quote Share this post Link to post Share on other sites
sundevil777 102 #8 March 3, 2003 QuoteI'm glad I am TSO'ed under TSO C23-b, which simply requires a harness to pass a 5,000 shock load test. Very interesting, so the different ratings (-b, -d, etc.) actually require very different proof of structural integrity. So a '-b' cert demonstrates that the H/C can withstand 20g for a 250lb load, and the '-d' cert only shows that it can take a normal reserve opening (probably no more than 4g?). Thank you Mr. Booth CliffPeople are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
PhreeZone 20 #9 March 3, 2003 My understanding is the D lets the company decide any numbers they want to say. There are no min, thats one reason the numbers are on the item. But my TSO knowledge is a bit fuzzy.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
sundevil777 102 #10 March 3, 2003 It lets the company decide what speed and weight for which they want to claim a rating. The harness will only be exposed to a normal reserve opening shock, nowhere near the load of the ground based-5000lb test.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
