markbaur

FreeDiver has a reasonable question that deserves a better answer. It doesn't matter where you draw the line between what's likely landable and what's likely unlandable. There will always be situations where you'll regret the decision you made at decision altitude. For example, suppose you were taught to steer using the rear risers in case of a broken steering line. That's a landable canopy, right? But what should you do if you then use up your upper body strength maneuvering below decision altitude, and you can no longer steer or flare your canopy? The SIM suggests a 2500' decision altitude, and also a 1000' do-not-cutaway-below altitude (below which your best option is probably to just pull the reserve ripcord, without cutting away). The hazard to cutting away as low as 1000 feet is not that the reserve will fail to open in time -- it probably will -- but that you won't have many options for where to land. Even so, I'd rather land on any obstacle with a functioning parachute than to land on the smoothest dz with a non-functioning one. (Grammer police can fix antecedents and dangling participles if they wish.) Mark

that you're more likely to have a malfunction on your next jump than to go any number of additional jumps and then have a malfunction. It gets worse. You're also more likely to have a double malfunction on your next jump than to go any number of additional jumps and then have a double malfunction. Ain't statistics grand? Mark

Straight from page 17 of the 2003 USPA Governance Manual: an S&TA must have the following qualifications: Our local S&TA holds a Tandem-I but no other instructional ratings. A USPA Tandem-I is an Instructor and can be an S&TA. In case of doubt, the requirement is waivable by the Regional Director. Club Safety Officers went out years ago with Area Safety Officers. The Regional Director can appoint more than one S&TA to serve a particular DZ. Mark

For ice to form on an airplane, it usually has to fly in clouds or in visible precipitation like rain. Most skydiving aircraft are flown under rules requiring them to stay away from clouds, and I don't think I'd jump in freezing rain. However, the colder it gets, the harder starting it is on the engine. The oil is thicker and doesn't lube the cylinders as well as when it is warm, so the piston rings rub harder on the cylinder walls, and everything wears out faster. Pre-heating the engine helps, but can take several hours. Mark CFII-ASMEL, CFI-G,H

Sec. 91.307 Parachutes and parachuting. (a) No pilot of a civil aircraft may allow a parachute that is available for emergency use to be carried in that aircraft unless it is an approved type < some stuff snipped out > (e) For the purposes of this section, approved parachute means-- (1) A parachute manufactured under a type certificate or a technical standard order (C-23 series); or (2) A personnel-carrying military parachute identified by an NAF, AAF, or AN drawing number, an AAF order number, or any other military designation or specification number.

Actually, we do. The metal handle peels the velcro apart. That's different than loading the velcro in shear, which is what you do when you pull a soft handle without twisting it. Mark

"Pull force" is the force required to extract the pin from the closing loop, not the force required to extract the handle from its pocket. I don't know of any standards for handle extraction forces. It takes a surprisingly small amount of velcro to exceed a joint strength of 20 pounds when loaded in sheer, so if you go with a pillow-type reserve ripcord handle, you'll need to peel it up out of its pocket before trying to pull the ripcord cable itself. Vector tandems have this double-velcro arrangement for both the cutaway and ripcord handles, and I think the other tandem rigs do too. Did tandem rigs in Finland get grounded too? What was the fix? Mark

1800skyride.com = Cary Vincent, Marietta, Georgia. Mark

USPA recommends, but does not require, recurrency training. If you have a lay-off over 90 days, then getting a B-license saves you money: -- With just an A, over 90 days USPA recommends a Cat D (level 4) AFF jump at $125-175, or a Cat B (practice pulls) IAD or static line jump at $25-45. -- With a B, all you need is a jump under an instructor's supervision, which can be as little as a 5-minute review of your jump plan, at no charge. I imagine going 90 days without a jump opportunity is rare in Florida. Here in Minnesota and western Wisconsin, it's quite common. Mark

The "calibrated" portable test chamber shown in FXC's ads appears to have an aircraft altimeter and an aircraft vertical speed indicator (VSI). The altimeter can be calibrated by an FAA-approved avionics shop to an accuracy of +75 feet, which combines with allowable firing range of + 300 feet. Most aircraft altimeters depend on aircraft vibration to help with needle movement, and I suppose the vibration of a vacuum pump might substitute. The VSI is more problematic. One of the tests requires a descent rate of 175 fps, something in excess of 10,000 feet per minute, but the mechanical VSIs I know of have a maximum indication of only 6000 fpm. If the $5500 FXC test chamber has an aircraft VSI with a maximum reading of 6000 fpm, it cannot be used to test FXCs. Further, IIRC, there are no FAA accuracy standards for aircraft VSIs, so accuracy is not guaranteed. I use a Stratomaster ALT-1 in my chamber. The ALT-1 is a digital altimeter/VSI intended for uncertified applications (experimentals and ultralights), but it goes periodically to an avionics shop for a ride in an altitude chamber to check the accuracy. The VSI maxes out at 9990 fpm, or 166 fps, just shy of the 175 fps required by the freefall speed test, but I think that's as close as any field equipment can get. Mark

I'm sorry I wasn't clearer. If a rig is not TSO'd, it is not legal to jump by anybody. There are no exceptions for master riggers to jump non-TSO'd reserves or harness/containers they've made themselves. I've cited FAR 105.43. What's your source? Mark

As a master rigger, I'm grateful for your vote of confidence, but I'm still bound by FAR 105.43, which requires me to use an approved (meaning TSO'd) harness and an approved (TSO'd) reserve. An exact copy of a TSO'd item is not TSO'd, since the TSO involves quality control (materials tracking and testing), as well as manufacture itself. If I wanted to jump a harness/container I made myself, I'd have to obtain my own TSO, even if I copied my favorite rig. No rigger rating is required to obtain a TSO. Your main is not TSO'd, and anybody can make a main parachute of any sort (bedsheet and four clotheslines as an extreme example) without FAA approval. Anybody can jump that main parachute, but there are rules about who can alter it. Mark

Thanks for the correction! Mark

IIRC, the X-210R is diaper-deployed, no freebag. Mark

www.atsb.gov.au/aviation/pdf/vh-mmv.pdf I was a visitor at another DZ last year when I asked the Cessna pilot why he was using his emergency chute just as a back cushion. "If I need it, I'll buckle it up then," he said. Mark

IRM Essentials is a pdf file available on the Manuals page in the Publications section of the USPA website. AFF renewal is on page AFF-2, the 15th page. Mark

The SST pop-top started as a version of the Strong pop-top chest-mount reserve, and the manufacturer's instructions used to say that a chest rating was sufficient. I do not recall anything in the original Wonderhog instructions, so I think it's unlikely that a Vector could be logged as a chest. I agree, though, that the FAA rigging regulations are quite dated, and I'm grateful that the FAA leaves most of the regulation to us. Mark

Somebody's been pulling your leg. If you saw a Javelin one recently, it was a beer holder. Mark

(Simplifying here...) The amount of drag is dependent on the projected surface. A flat circular has less projected surface than the equivalent conical. Check out your Poynter's manual, in the chapter on parachute design and construction. Mark

The first canopy I owned! The Cruisair was made of 1.25 oz fabric, a departure from the Strato-Cloud/Strato-Star 1.55 oz fabric. Para-Flite had not yet started making canopies from F-111. It came without crossports, and it tended to open with end cell closure. I had about 100 jumps when I cut the crossports and did the stabilizer mod myself, removing the stabilizer fabric between the A and B lines. The Cruisair was advertised as 200 square feet, but IIRC the Pegasus was an almost exact copy (but made from F-111 and with improved line trim) and was advertised as 220 square feet. There was no standard measuring protocol at that time. The Cruislite was the F-111 version of the Cruisair. I think they were the same size, with Para-Flite choosing to use their competition's measurement method for the Cruislite, hence the 220 square foot size. Mark

A conical parachute having the same drag as a flat circular has less surface, so we cannot say so simply that more surface = more drag. Mark

I owned one. 260 square feet. Mark

Failure to pull should not be an automatic Level 1/Category A bust. If the rest of the dive went well, but a jumpmaster pulled because the student misread the altimeter, then Level 2/Cat B should probably be next. After all, you're not planning to let go on Level 2/Cat B -- and static line Cat A doesn't even require an attempted ripcord pull for advancement to static line Cat B. I would recommend another Level 1/Cat A skydive only if the student needed additional time to be comfortable in the environment and was unlikely to be able to perform Level 2/Cat B maneuvers. Mark

And there is also a significant difference in comfort when jumping the canopy-first deployment of a WWII T-7, as opposed to the lines-first deployment of a T-10, which first appeared part way through the Korean War. Mark

Stability at pull time is good, but if you are below your pull altitude, it's time to pull regardless of stability. Mark