Reserve Parachute Deployment

[paulzeee 0]

Hey guys and gals,

I've been looking around for information on how long it takes for a reserve to fully deploy/inflate. I know there are a few different factors in this but a general starting point would help.

thanks

[sebcat 0]

Tadam: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1917044 :)

[kingbunky 3]

the book says 300 feet. at belly-down terminal, that's about 2 seconds. if you cut away from a malfunction, you would be going much slower so the 300 feet would take longer.

"Hang on a sec, the young'uns are throwin' beer cans at a golf cart."
MB4252 TDS699
killing threads since 2001

[paulzeee 0]

Awesome, thanks a million.

[pilotdave 0]

This is a fairly accurate (to scale) series of pictures of a cutaway and reserve deployment.

Dave

[paulzeee 0]

Thanks for that. Mind if i use it in my report?

(all this is for school)

[mjosparky 4]

AS8015-B

4.3.5 Functional Test (Twisted Lines): A minimum of 5 drops shall be made with a weight not more than the maximum operating weight dummy or person3 in each harness. The airspeed at the time of pack opening shall be 60 KEAS (111.1 km/h). Three twists in the same direction (360° each) shall be purposely packed in the suspension lines adjacent to the lowest attachment point to the canopy. The
parachute must be functionally open within the time calculated for 4.3.6 tests +1 s from the time of pack release.

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).

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

[paulzeee 0]

I googled this - AS8015-B - and came up with a few things but had to pay for them... what source is this coming from??

Can you link me please?

Thanks

[pilotdave 0]

Sure, you can use it. Make sure you format the bibliography correctly.

Dave

[paulzeee 0]

Ha i know right, Good ole APA

[pchapman 279]

For the orig. poster (sparky knows this stuff and can correct any error of mine):

As for the AS8015 stuff, note that the 3 seconds is to the moment the parachute reaches full inflation -- not until the time when the canopy is flying in a nice steady state descent.

After the 3 sec it may still be mushing downwards with a bunch of extra velocity, or pitching from the opening. And it will be in brakes and not ready to land normally. It'll take some seconds to undo the brakes, let it come out of the resulting dive, and then flare.

So the 3 seconds is technically fine for saving your life, but another 100 or 200 feet would be really nice to have to avoid smashing ankles in real life.

[JerryBaumchen 1,367]

Hi paul,

Now you have been provided with 'some' information.

When you use the term 'how long' I define that to mean in time, not altitude ( but I'm waayy old school ).

In TSO C23(b) it is a max of three seconds for the Functional Tests & four seconds for the Twisted Lines Test. There is no altitude option mentioned.

As I have said forever & a day, there are three TSO standards that parachute equipment can be purchased under. And a prudent buyer would know which TSO the equipment that he/she is considering purchasing would fall under. This is particularly important for the Strength Testing that each item has been certificated under.

Do these reply posts answer your question(s)?

JerryBaumchen

[mjosparky 4]

See Attachment:

Sparky

My idea of a fair fight is clubbing baby seals

[paulzeee 0]

Quote

Hi paul,

Now you have been provided with 'some' information.

When you use the term 'how long' I define that to mean in time, not altitude ( but I'm waayy old school ).

In TSO C23(b) it is a max of three seconds for the Functional Tests & four seconds for the Twisted Lines Test. There is no altitude option mentioned.

As I have said forever & a day, there are three TSO standards that parachute equipment can be purchased under. And a prudent buyer would know which TSO the equipment that he/she is considering purchasing would fall under. This is particularly important for the Strength Testing that each item has been certificated under.

Do these reply posts answer your question(s)?

JerryBaumchen

Most certainly. It's all relevant for my report. Thanks again.

[JerryBaumchen 1,367]

Hi sparky,

During the summer of 1979 NAS 804 was my 'bible.'

I need to get off of my keester and write something up about the testing we did back then.

JerryBaumchen

[erdnarob 1]

With a cut away and having a Skyhook it will take 75-100 feet (see UPT Vector demo video). If you have a reserve with a strong pilot chute jumping at 5 feet or more, you have less chance to get a pilot chute hesitation due to the burble behind you in free fall in case of a total malfunction. Now what rig has both the Skyhook and a strong pilot chute jumping at 5 feet or more : ie the Vector III. I made a comparative study of pilot chute launch when the reserve handle is pulled and so far 2 rigs have their pilot chute jumping at more than 5 feet (vertically), the Vector III and the Quasar II. I have tried about half a dozen of rigs.

Learn from others mistakes, you will never live long enough to make them all.

[BKR 0]

Hi André,

you forgot Advance and Seven reserve pilot chute. No MARD.

Jérôme Bunker
Basik Air Concept
www.basik.fr
http://www.facebook.com/pages/Le-Luc-France/BASIK-AIR-CONCEPT/172133350468

[mjosparky 4]

Quote

I googled this - AS8015-B - and came up with a few things but had to pay for them... what source is this coming from??

Can you link me please?

Thanks

Here you go Paul.

Sparky

My idea of a fair fight is clubbing baby seals

[KellyF 16]

Quote

With a cut away and having a Skyhook it will take 75-100 feet (see UPT Vector demo video).

Slider down doesn't count A MARD will get the reserve out of the bag at about the point where the reserve pilot chute is at it's highest point in the picture that PilotDave posted. The rest of the deployment will come down to what kind of canopy is coming out of that bag.

[mjosparky 4]

Quote

Hi sparky,

During the summer of 1979 NAS 804 was my 'bible.'

I need to get off of my keester and write something up about the testing we did back then.

JerryBaumchen

Jerry,

Great picture, which one is the test dummy?

Sparky

My idea of a fair fight is clubbing baby seals

[upndownshop 0]

Quote

For the orig. poster (sparky knows this stuff and can correct any error of mine):

As for the AS8015 stuff, note that the 3 seconds is to the moment the parachute reaches full inflation -- not until the time when the canopy is flying in a nice steady state descent.

After the 3 sec it may still be mushing downwards with a bunch of extra velocity, or pitching from the opening. And it will be in brakes and not ready to land normally. It'll take some seconds to undo the brakes, let it come out of the resulting dive, and then flare.

So the 3 seconds is technically fine for saving your life, but another 100 or 200 feet would be really nice to have to avoid smashing ankles in real life.

I've always said a canopy needs to breathe once before it will save your life. Meaning it needs to take the air it used to open it and "recycle it" before it slows the decent rate enough to prevent injury or death. This is only based on what I have seen with opened canopies just after line stretch then impact, both died. 1 round, 1 square. I could be very wrong though.

[JerryBaumchen 1,367]

Hi Sparky,

That is Mick Bevens with the dummy; 1974 US Team member, great rigger & just possibly the best sewing machine mechanic I have ever known.

I'll try to get a photo of the dummy & me together so you can take the test.

JerryBaumchen

PS) Oh heck, here it is and I was a lot younger then, a little slimmer also.

[mjosparky 4]

Quote

I'll try to get a photo of the dummy & me together so you can take the test.

Oh sure, now I have to pick between 4 dummies and a Blond. My head hurts, I need some Gray Goose.

Sparky

My idea of a fair fight is clubbing baby seals

[JerryBaumchen 1,367]

Hi Sparky,

Quote

Oh sure, now I have to pick between 4 dummies and a Blond. My head hurts, I need some Gray Goose.

As soon as you finish the Gray Goose it will be easy.

That guy behind me with the tossled hair was the pilot; his name was Leonard, I never did know his last name.

He is a real success story out of the Sheridan dz ( maybe the only one ). He started out there at about 14 yrs old just sweeping the floors for something to do & some money. He then took flying lessons at the dz; got a goodly amount of hours & started flying jumpers ( or maybe vice-versa knowing Ted ). Eventually, he went to work for a small airline in Alaska as a commercial pilot. He was a real quite guy but a real decent sort of guy.

With all of the 'lets bash Ted Mayfield' stuff here ( and deserved IMO ) I thought folks might like to see a positive story about Ted.

JerryBaumchen

[Cambalectri 0]

I agree with erdnarob concerning the Vector3 and the Quasar II pilot chute travelling vertically 5 feet+,
but, I noticed , the Quasar was slightly better. However, I believe they both used the same spring, but not in the same configuration, one with the wide end of the spring, sitting on the inside flaps of the reserve, the other, with the wide end near the top !