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Curious about deployment speed to flying canopy from a direct bag??

ok.
could you be more precise?
take care,
space

Let me rephrase then. What would be the average time from the moment the jumper leaves the edge to a fully inflated canopy??

"Time" and "fully inflated"depend on so many factors. I'll talk of a measure that is pretty much consistent with every canopy I've seen, that is Distance the canopy travels from the time it leaves the bag to when bottom-skin expansion occurs. You can add the variables that you know that are particular to your system to determine time to full flying canopy. These variable include the launch taken (up/out/dropoff) and the factors that help achieve pressurisation (vents/sq-ft/surge/brake-settings/+others)

Distance: Every canopy I've seen would achieve top-skin inflation after travelling about 25' from the bag. Sometimes it has seemed even less. 25' would be the average from my experience when witnessing from above or the side or holding the bag itself.

Launch: Launching out would create an arc that extracts the lines a bit more before the jumper would start to descend and skin-inflation would occur slightly higher. The problem with launching as opposed to dropping-off is the effect it has on pressurisation and fwd-surge by increased pendulum effect. Launching out to achieve a faster bottom skin inflation may work against you to achieve "flying" status due to surge so you need to be dialed into your canopy's brake-setting and so forth to work out if this is a good idea or not.

I am assuming for these jumps you have a competent bag-holder and a correctly routed and anchored safety bridle.

Rigging tricks for supa low shit.: A trick we used if going off something really low was to place a light break cord or rubber band connecting the canopy attachment point to the inside-top of the bag.This will hold the top of the canopy in-place until the bottom folds of canopy have left the bag allowing the canopy to leave the bag in a staged order will full line-stretch, rather than as a clump of folded material that has to unfold as the jumper tows it thru the air. The break cord need only be strong enough to hold the top while the bottom extracts - you dont need much breaking strain. We used rubber bands. Standard break cord may be too strong for this purpose and may rip the bag from the holder's hands. Dropping the bag at this stage usually isn't a problem as the lines and canopy are already at full-stretch and the canopy is 90% out and on-heading. You should debrief the bag-holder about this as a small snatch will be felt when holding the bag as the last of the canopy is extracted.

Removing the tailgate will allow a slight increase in initial skin expansion. For this you need to use a D-bag that has stowing bands to stage line deployment. The last 2 stowes to release (primary stows) should have a good amount of tension. This ensures the lines are at full length and tension before any canopy is extracted. If you do this in conjunction with a good packing technique with an emphasis on nose-first inflation and tail management then the chances of line-over are pretty much eliminated. Use the line-mod. The air-speed during D-bag deployments is pretty slow and slight tail-gate hangup when you are really low is bad JuJu.

The above is just a few points that will help you achieve inflation in the minimum amount of altitude. It is by no means all there is to cover about D-bag jumps. There's many other threads to read on this subject - just search. I also urge you seek the opinion of others on my techniques.

g.

Thank you, for taking the time to post your experience and techniques using a direct bag.

At this point basic theory is all I'm looking for. And the interest is for low objects, as I'm a bigger than average jumper.

An incident early in the "List" gives us an example (I'm sure there are several others) of why you want someone competent holding the bag. (rip)

Lets say that your question is not easy to discuss in general and in public. Behind every statement stands a special history and experience. This is not automatically valid for any kind of forum information consumers.
Even only for basic theory, at one point theory gets practic.

Still my two cents:

Opening speed also depends on your weight, your canopy age, kind and size, your packjob and your jump energy due to the object. Logically all other factors you need for BASE still must be concerned (and I can not tell how much infos are additionally available in this forum).

Maybe the canopy is inflated after 25ft (as GaryP mentioned above) but it doesn’t fly enough at that point to be landable. You still will use up some more altitude till you have a landable aerodynamic performance.
We have tested some special rigged stuff from 45ft over water (we used also the hold back modification with velcro shrivel on a multi and had a solid attachmentpoint to address the down sucking force). The canopy had of course fully opened even quicker than 25ft but it was also obvious that it was impossible to land on hard surface without serious injuries (think also about line length and jumper size).

We jump DBs regularly between 40-25m. For 40m a first DB timer can have fun. For 25m you must definetely be a DB Pro with a Pro Support.
To have a good DB performance overall you should not try to learn this autodidactically by yourself. You must have an experienced person who introduces you in all specific details. As mentioned above, you also need a competent supporter every time.
There were tailgate hangups with DB because of wrong setups* and off headings, too. Therefore you must develop a personal knowledge of how you want to do this. At least a DB is no guarentee that you can go very low without care.

*as I knew there was a canopy which was folded as a Skydiving canopy and then sticked into the bag at once instead of using caterpillar folds which should be compressed fold by fold into the bag. Also there where done to many wraps with a strong tailgate rubberband which kept the tailgate from opening (I still think it is a good idea to use a tailgate as long you use a weak rubberband with only 2 wraps).

Personally I like to jump as far as I can away from the exitpoint to create some kind of momentum to support inflation (like inflating a hang glider for take off). Additionally this increases the distance thru the air in some microbiotic way.
By doing this the angle of the canopy gets close to a dynamic stall during stretch and inflation (because you are a little to far ahead of the leading edge). Therefore I use brake setting #1 to compensate some of this effect and to minimize a rough pendulum. This brake setting also can help to land it with rear risers with the brakes still set if time is to short to plausible release them.
You may change this if you jump a bridge where you haven't to jump to far to the front. There it is maybe good to use brake setting #2 to form more lower surface resistance.
And of course, in both ways you should use a VTec/MDV canopy to speed up inflation anyway.

But that is all just the top of the visible iceberg. Look for someone who knows about the facts and learn (more of) it adequately from him by pratical instructions.

Schüttelsack macht Laune
M.

In a headwind opening direction, the point of fully inflated canopy will be faster. Downwind opening direction, the distance is somewhat slower. But not by much. But one will need much more altitude to come out of the dive.
The major concern for ultra low DB, Is that one is not certain of the opening direction until opening. A downwind opening direction can dive you into the ground whereas an into the wind can make seem like a walk in the park. all from the same altitude.

As Mahle said "Maybe the canopy is inflated after 25ft (as GaryP mentioned above) but it doesn't fly enough at that point to be landable. You still will use up some more altitude till you have a landable aerodynamic performance. "
This is the key. Landable aerodynamic performance.

The main sequence is:
Extraction.
Line stretch.
Positioning.
Inflation bottomskin.
Inflation internal (topskin).
Movement producing lift.
A 2nd positioning to where the the canopy is stabilized over ones head.
Stabilized flight.

Hope this helps,
take care,
space