How long does it take for your reserve to open?

[docjohn 0]

There's an interesting comment in the first indcident report in the November PARACHUTIST (p 63).

"At 900 feet, there was barely enough altitude for reserve inflation even if the deployment had been initiated immediately with a reserve static line or by manually pulling the reserve handle."

My Stiletto and Pilot canopies open in less than 500 feet at terminal. I would hope my reserve would open faster than my main.

Doc
http://www.manifestmaster.com/video

[Hooknswoop 19]

To pass TSO testing a reserve has to open within 300 feet. That can increase for higher weights, but almost all need to be open within 300 ft.

Derek

[ladyskydiver 0]

Mine opens in approximately 400 feet. It's actually probably closer to 350 feet, but I round up to an even 400.

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[JohnMitchell 16]

It takes one breath to open because I always hold my breath until it does open.

I don't think mine has ever taken more than 300 feet to open. Tandem reserves a little slower, but not much.

I've seen more than one cutaway done at 1000 feet or lower, quite successfully. However, that is a situation I try to avoid.

"Parachutist" magazine tends to be very conservative in their approach to emergency procedures, which is probably a good thing. If they were to say that you could chop at a grand and live, too many noobs would take it as gospel that that was okay. It's not, it's survival time then.

[FrogNog 1]

Quote

"At 900 feet, there was barely enough altitude for reserve inflation even if the deployment had been initiated immediately with a reserve static line or by manually pulling the reserve handle."

My Stiletto and Pilot canopies open in less than 500 feet at terminal. I would hope my reserve would open faster than my main.

Did the parachutist article indicate the reserve deployment started at terminal?

Do canopies take more altitude to get to line stretch when they are deployed in a low-airspeed situation (such as cutting away from an open canopy) vs. a high-airspeed situation (such as a nothing-out activation)? I should note that hop-and-pops at 80 MPH would be a medium-airspeed situation.

-=-=-=-=-
Pull.

[Hooknswoop 19]

Quote

Did the parachutist article indicate the reserve deployment started at terminal?

Do canopies take more altitude to get to line stretch when they are deployed in a low-airspeed situation (such as cutting away from an open canopy) vs. a high-airspeed situation (such as a nothing-out activation)? I should note that hop-and-pops at 80 MPH would be a medium-airspeed situation.

Doesn't matter, the reserve should be open is less than 300 feet, regardless if you are at terminal or not. Of course you would want to pad that number. If your reserve takes longer than 300 feet, something is wrong with either the container or the reserve.

Derek

[mjosparky 4]

AS8015-B

4.3.6 Functional Test (Normal Pack All Types): For all 4.3.6 tests the maximum allowable opening time for
parachute canopies with a maximum operating weight of 250 lb (113.4 kg) or less, is 3 s from the
moment of pack opening. For parachutes with a maximum operating weight of greater than 250 lb
(113.4 kg) the maximum allowable opening time shall be increased by 0.01 s for every pound of
maximum operating weight in excess of 250 lb (113.4 kg).

4.3.6 (Continued):
Alternatively altitude loss instead of time may be measured and the maximum allowable altitude loss
may be calculated as follows.
For all 4.3.6 tests the maximum allowable altitude loss for parachutes with a maximum operating
weight of 250 lb (113.4 kg) or less is 300 ft (91.5 m) from the altitude at pack opening. For parachutes
with a maximum operating weight of greater than 250 lb (113.4 kg) the maximum allowable altitude loss
shall be increased by 1 ft for every pound of maximum operating weight in excess of 250 lb (113.4 kg).
NOTE: Altitude loss measurements must be measured along a vertical trajectory only. However, the
deviation from the vertical produced by a gliding main parachute descending with a vertical
velocity of less than 20 FPS (6.1 m/s) shall be acceptable.

Sparky

My idea of a fair fight is clubbing baby seals

[billbooth 10]

These tests are almost always done static line from (obviously) a horizontally moving aircraft. This means that initially, the load has lots of airspeed, but very little rate of descent. If the load were freefalling at terminal velocity, and the pack opened at 300 feet, very few, if any reserves would pass.

But the more important point here is, that when you make the decision to pull, and when you actually do it, is often separated by several seconds...which at terminal can mean 500 feet or more. Of course, then there are pilot chute hesitations. Because everyone now hand deploys their main parachutes, very few people seem to remember what a problem they were...and fewer still no how to avoid them at pull time. These can easily eat up up another few hundred feet.

The point here is that if you are at terminal, the time from the decision to pull, to a fully open and functioning reserve, can be a lot closer to 1,000 feet than 300 feet.

[Reginald 0]

Quote

These tests are almost always done static line from (obviously) a horizontally moving aircraft. This means that initially, the load has lots of airspeed, but very little rate of descent. If the load were freefalling at terminal velocity, and the pack opened at 300 feet, very few, if any reserves would pass.

Good info! I never knew how the tests were performed. That’s a little disconcerting though. My Sabre2 takes 800 feet to open at terminal but on a hop n pop, pitching just after I pass the tail I only lose about 300 to 400 feet. Now I’m wondering how long it really take my reserve to open at terminal??? I do know how long my reserve takes to open on a cutaway…I field tested a skyhook.

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[mjosparky 4]

I agree, the altitude loss will vary with descent rate speed. But 3 seconds will always be 3 seconds. Is that why most manufactures choose to test to the time criteria rather then the altitude loss.

4.3.6 Functional Test (Normal Pack All Types): For all 4.3.6 tests the maximum allowable opening time for parachute canopies with a maximum operating weight of 250 lb (113.4 kg) or less, is 3 s from the moment of pack opening. For parachutes with a maximum operating weight of greater than 250 lb (113.4 kg) the maximum allowable opening time shall be increased by 0.01 s for every pound of maximum operating weight in excess of 250 lb (113.4 kg).

Sparky

My idea of a fair fight is clubbing baby seals

[udder 0]

with regard to popping the pin on the reserve, do pop tops have an advantage when it comes to preventing pc hesistation on reserves? or is strength of the spring more important? and which reserves open quicker?

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[skydiverek 63]

Ask John Sherman .

[Hooknswoop 19]

Quote

with regard to popping the pin on the reserve, do pop tops have an advantage when it comes to preventing pc hesistation on reserves? or is strength of the spring more important? and which reserves open quicker?

From popping reserves, flaps don't seem to make a difference in the launch of the PC. Spring length/strength seems to make all the difference. The flaps just aren't that stiff to imped the launch of the PC.

As for the fastest opening reserves, the smallest reserves deploy the fastest. Same size PC dragging less weight, less airspace to inflate. That being said, don't use that as a reason to get a smaller reserve.

Derek

[mjosparky 4]

Quote

Ask John Sherman .

No, ask Ted Strong.
Sparky

My idea of a fair fight is clubbing baby seals

[billbooth 10]

Quote

Quote

Ask John Sherman .

No, ask Ted Strong.
Sparky

No, ask Dan Pointer, who invented the pop top in the first place (while working for Ted Strong.

[udder 0]

Is the reserve PC size a compromise between high and low speed deployment speeds? Is the spring strong enough, with enough weight to pop the pin instantly in very low speed mals?

please excuse if these questions sound stupid.

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[billvon 3,075]

>Is the spring strong enough, with enough weight to pop the pin instantly in
>very low speed mals?

The spring is strong enough to open the container when standing stationary on the ground; indeed, the PC will generally launch several feet in the air. There have been a few rare instances of this not working (i.e. the Talon heat treatment problem) but that's how it works 99% of the time.

[mjosparky 4]

Quote

Quote

Quote

Ask John Sherman .

No, ask Ted Strong.
Sparky

No, ask Dan Pointer, who invented the pop top in the first place (while working for Ted Strong.

Ah, not the whole story is out. First time I have heard Dan's name in the mix. Thanks for the info.

Sparky

My idea of a fair fight is clubbing baby seals

[billbooth 10]

Quote

Quote

Quote

Quote

Ask John Sherman .

No, ask Ted Strong.
Sparky

No, ask Dan Pointer, who invented the pop top in the first place (while working for Ted Strong.

Ah, not the whole story is out. First time I have heard Dan's name in the mix. Thanks for the info.

Sparky

Sometimes it pays to be ancient...and Ted and John are even more ancient than I.

[riggerrob 643]

Quote

Is the reserve PC size a compromise between high and low speed deployment speeds? Is the spring strong enough, with enough weight to pop the pin instantly in very low speed mals?

please excuse if these questions sound stupid.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

To clarify, all reserve pilot chutes launch AFTER the ripcord pin is pulled (or Cypres cuts closing loop).

Modern springs are more than strong enough to push side flap stiffeners out of the way.

Reserve pilot chute fabric is optimized for the low speed end of the scale, which means that they are too big at the high speed end of the scale.
Fortunately, all the other components (freebag, safety stow, etc.) are strong enough to sequence high speed openings properly. Since the pilot chute disconnects right after the freebag opens, the jumper is never jolted by a too-big reserve pilot chute. Ergo, Mr. Booth can use the same reserve pilot chute on canopies ranging from 97 to 420 square feet.

[riggerrob 643]

Quote

with regard to popping the pin on the reserve, do pop tops have an advantage when it comes to preventing pc hesistation on reserves? or is strength of the spring more important? and which reserves open quicker?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

If you are low enough for your choice of reserve containers to make a difference (i.e. Pop-Top versus Mirage) you have made a whole series of mistakes on your way to the scene of the accident.