DBTECH

If you smoke-QUIT NOW, as nicotine disrupts the electrical functions/pathways in the heart-big time. Dave Brownell

Unlike LO-PO or F-111 type materials that have a relatively high open area--ZP material is relatively 'sealed' because of the coating. It is for this reason that the material lasts longer, because abrasive dirt cannot enter the fabric to do it's evil dead. Also, the much lower coefficient of friction of ZP, means very low wear. Dave Brownell

There was a low hook turn crash and burn Sunday at Eloy forty minutes before I arrived mid-morning. He was medavaced out complaining of severe lower back pain. This is all I've heard. Dave Brownell

I must agree with Dan on this one, as in turbulence/wind shear, the highest airspeed is desired, not only for higher cell pressurization, but for the unknown 'horizontal component' of wind shear, which can cause a stall. A full stall/dive at very low altitude-due to horizontal wind shear, can ruin your day also. Dave Brownell

For collapsible PC's, I would recommend Jim Cazer in Taladaga, Alabama. He makes many OEM PC's and will also sell direct to anyone. (forget about ParaGear) The trend is favoring smaller PC's these days. (finally-as I've been preaching this for more than ten years--21" ZP PC, last six years) Of course, I would recommend nothing larger than a 24". For pilot chutes-- Jim Cazer PH 256-268-9843 [email protected] Dave Brownell Mesa, AZ

Commercial dye's for Nylon, are in fact, acid dye's. I have an assortment of acid dye's/colors from Mobay Chemical Co. The ideal 'mix PH' is 5--I use common distilled water, with a hard boil on my kit stove, followed by a good hot water rinse. Dying non-dyed or non-heat shrunk/stabilized Nylon will increase the elongation, and increase the tensile strength. I have dyed many different types of webbing and tapes over the last 15 years. i.e., Ty-17 for risers, Ty-IV square weave for bridles, Ty-III binding tape, and many other Mil spec/non Mil spec Nylon goods. Example--5/8" Ty-IV square weave is only available in black or white-unless by special order from Bally, with a ridiculous minimum yardage amount. Yes, the bridle on my rig is 5/8" Ty-IV--yellow. Dave Brownell Mesa, AZ

Posted eariler 2001 Jaime asks: >>Can anyone tell me anything about integrity risers? >>Thanks for your time. Integrity risers were first dreamed up because of the fear of riser failure only on the side with an RSL connection, during a very fast/hard opening, which would result in a main-reserve entanglement. (Yes, it has happened. Integrity risers are built without a grommet in the riser for the cable loop. Instead, there is a tab on the ring side of the riser that has the grommet. Integrity risers are installed on the harness ring in reverse (riser rings toward rig). Integrity risers are stronger because of their absence of a grommet hole. There are two negatives regarding integrity risers. The first is the fact that the loop mechanical advantage is close to half that of conventional risers, which in fact reduces the total mechanical advantage to close to half also. The reason that they have reduced mechanical advantage is because there is no longer a loop around the small ring, but a near straight line between the loop attachment point and the locking cable. There is in fact recorded cases, where under a high G spinning malfunction, where the release cable was pulled into the grommet somewhat, due to the higher forces, which resulted in a very hard release cable pull. When you consider this factor combined with the high friction of soft housings, you can see the potential of a deadly combination. This is not just my opinion, but is one shared by many in the industry. As far as stainless housings, I recommend keeping them clean, along with clean cables with a little silicone applied. Regular maintenance will keep them at a low coefficient of friction. The second negative is the possibility of not getting a riser release because of a combination of lower harness rings locations and a somewhat face to earth under a low drag malfunction. Rigs/harnesses made today are made with this in mind to assure high harness rings locations. I do not use an RSL, but I do like the strength advantage of a hole-less TY-17 riser. As far as a canopy with high spin rates associated with malfunctions being used with integrity risers, I myself have no problem with integrity risers, because of the factor of housing/cable maintenance. I once had a very fast/hard, brutal opening on a Spectre 170 with integrity risers. When I examined the loop/grommet/cable point there was no evidence of penetration of the cable into the grommet, which in my opinion, gave me a better "feel" for the total mechanical system. I recommend the use of the short metal excess cable housings installed in the stow channel in all risers, be it type 8 or type 17. These housings will prevent release cable capture/binding after a severe riser twist due to a severe canopy spin. 1/4" OD X 0.035" wall Teflon tubing works great also. One tack with Nylon wax cord 1/4"-3/8" from the inserted end holds it in place. I'm not trying to put down type17 integrity risers, as I have used them myself. Ultra blue skies, Dave Brownell DB Technologies Mesa, AZ

I never said that a higher opening altitude would not cause a harder opening. A higher altitude to me is not 500 to 1000, but 5000+. I am talking density altitude here, which Eloy has little to nil over other DZ's elsewhere in the country. I have been in Illinois when the density altitude was 6000 feet--very hot HUMID day. Eloy, BTW is only 800 feet above SDC. Again, the Placebo effect comes to mind here in regard to Eloy. BTW: I do have 300 jumps at Eloy-900 in Illinois. Dave Brownell

(dry air is MORE dense than humid air) >Isn't that the other way around? >Humid air will have more water content and therefore be denser.... DB--As I said-dry air is more dense than humid air--ask any pilot --also check physics books for a good explanation as to why. Dave Brownell C-180/182 Jump pilot-(2700 loads

BTW people-we don't slow down TO terminal-we slow down to a 'new-slower' terminal. Someone said--harder openings at Eloy because of a field elevation of 1500 feet--I don't by it--The Placebo effect comes to mind here. If you came from a sea-level DZ and opened at 2000 feet AGL/MSL, that would be 3500 feet MSL at Eloy. Plus it's density altitude that counts-and at Eloy it's always lower for a given temperature because of the low desert humidity. (dry air is MORE dense than humid air) Dave Brownell Mesa/Eloy AZ

A deceleration from 120 MPH to 10 MPH over a distance of 30 feet would be 16 g's nominal-which is well into the range of a gut wrenching opening. The above is derived from good math--not fuzzy math. The above model is for a constant 16 G's over a distance of 30 feet. Yes-been there-done that-no fun. (both steering lines broke, and the opening actually deformed two #4 Stainless/delta connector links!--(I did land it via the rear risers) (PD-210-line dump-ten+ years ago) The above opening was probably into the realm of less than 75 feet/16 G's peak--based on the damage to the connector links, riser dive loop stitching, and broken lines-(especially the connector link deformation, which I have a good feeling for--for the numbers. Even with 'only' 700 lbs. peak on each riser/connector link-that would be 16 G's peak! 4 X 700=2800 over 175= 16 G's-ouch! Ya dig! Dave Brownell Mesa, AZ

Must be witchcraft/magic--Ask Harry Potter--he'll know! Dave Brownell

>and that canopies open in about 120 feet. -------------------------------------------------------------------------------- Jimbo responded--> Yikes! Maybe old Sabre's. A canopy opening in 120 feet could literally break your back. That would be bad. DB> Not really 'that bad'---'data' from my article---> A deceleration from 120 MPH to 10 MPH over a distance of 30 feet would be 16 g's nominal-which is well into the range of a gut wrenching opening--Yikes, for sure! Yes-been there-done that-no fun. (both steering lines broke, and the opening actually deformed two #4 Stainless/delta connector links!--(I did land it via the rear risers) (PD-210-line dump-ten+ years ago) The canopy was packed by a master rigger who claimed to have all the answers--but I now know, like many--he's yet to see the questions. Dave Brownell Mesa, AZ

Normal opening forces (not snatch force) occur over a period of approximately two to four seconds, over a distance of two hundred feet or more. Mean/normal deceleration numbers are 2 to 4 g's. Check out my article on opening physics at--> http://dzsports.net/dznewsbin/news20018.html Dave Brownell Mesa, AZ

Sounds like many good new ideas--I do know about Teflon based lubes--good stuff. Please let us know about the use of the 'Bore Snake'--sounds like a neat device. BTW: To the person that said 'Silicon'--it's 'Silicone'--Silicon is a crystal--it is the foundation of modern semiconductors/electronics. i.e, transistors and integrated circuits. Silicon is pronounced- Sill short-i cun Dave Brownell

Mike said-- I use ZP pilotchutes because they last longer and provide consistent openings.. Openings will change with an F111 pilotchute over time as it loses porosity.. DB> You do mean--as it gains/increases porosity? (as compared to ZP that remains constant) Dave Brownell

You say he lost it in the woods--how much of the canopy was shaded by the woods? Also--where do you live?--what latitude?-->(UV factor) How many jumps are on this canopy? Dave Brownell

Tuesday morning on ABC's Good Morning America, there will be a segment on building escape parachutes! Dave Brownell

Tuesday morning on ABC's Good Morning America, there will be a segment on building escape parachutes! Dave Brownell

Check out this DZ in Africa--in attachment Dave Brownell

Hook knife--Federal offence!? Having a hook knife attached to your rig, and then bringing it on board a commercial flight as carry on, may now be a Federal offence!? Dave Brownell

You are saying that the webbing is--your quote- "Although it does curl the riser material in a U shape." If in fact you have 1" wide TY17 mini risers, this tells my that you may indeed have the smaller (20 MM) stainless grommets, as 25 MM grommets are 1" ID! (20 MM stainless grommets are 0.8" ID. Do a measurement. Dave Brownell

When PD first started offering stainless grommets, there were two sizes--20 MM & 25 MM. 20 MM will not pull down over TY 17 risers--after many complainants, PD stopped offering the smaller stainless grommets--maybe you have the 20 MM grommets? Dave Brownell

Test jumpers wanted in Arizona and southern California. (also looking for someone that jumps a Sabre 150 on a regular basis in AZ or southern CA) See the article at the following link for information on the project-- http://dzsports.net/dznewsbin/news20018.html Dave Brownell

Test jumpers wanted in Arizona and southern California. (also looking for someone that jumps a Sabre 150 on a regular basis in AZ or southern CA) See the article at the following link for information on the project-- http://dzsports.net/dznewsbin/news20018.html Dave Brownell DB Technologies Mesa/Eloy AZ