IAD - v - Direct Bag

[tinay 0]

I have a great deal of experience with Direct Bag (DB) Static Line deployment, but would like to compare the two methods and get an idea of what REALLY is the best method of the two.

The cons. for DB are:

Twist are common, even when flying the a/c slowly.

Students can get parts of their body caught in the rigging lines (probably one of the worse problems a student could face, if the have a mal, trying to release their limbs before cutting away, or cutting away whilst still attached!).

I have no experience of IAD and would like to hear of genuine problems or incidents:

What happens, or has it happenned - a student leaving the a/c before the instructor has extracted the pilot chute?

Can/has the pilot chute entangled with the student.

I don't really want to hear about shouldn't happen if instructor does his/her job properly. Is the system instructor/student proof? DB static line tends to be!

[Andrewwhyte 1]

i learned on an IAD system 22 years ago with round mains and belly-band throw outs. As a result I have a bias towards the IAD system.
The biggest advantage to the IAD system is that the deployment is in sequence. The pilot chute goes downwind of the pin prior to extraction and the entire deployment is exactly like a free-faller's.
The two main disadvantages are the possibility of a tail strike and the possibility of the student capturing the P/C. The former happened to a jump-master candidate during a course in the eighties (I am muddy on the particulars but I think he lost a leg), and the latter caused a fatality in the nineties for a first jump student.
Both of these problems are caused by the same mistake by the instructor- letting go of the pilot chute too soon. When the J/M lets go of the P/C it immediately goes down wind of the next point of resistance. Normally that is the pin, followed quickly by the large rings on the harness. If the student has not let go of the aircraft (say on a 182 hanging exit) then the large rings on his harness are above the horizontal stabilizer, and the pilot chute goes over the tail. The most likely time for this scenario is in the event of a bag drop. When the instructor sees the container open they want the student gone; throwing the pilot chute is, however, exactly the wrong thing to do for the reasons I just stated. If the J/M holds the P/C the bag falls down, the canopy comes out and begins to inflate below the stabilizer. When the drag pulls the student off, the J/m releases the P/C and the student falls away. I have never faced this scenario but I have been on the DZ for three or four of them over the years. Usually the student goes before the canopy comes out, but in every case I've seen the student got a functioning canopy. If the J/m fucks up the pilot should be trained to push the tail away and to roll right.
If the student rolls over on exit fast enough to trap the P/C (a remote yet non-zero probability) the same action is required- hold the P/C a bit longer. This insures the pin is pulled. I always tell the junior J/Ms, "It is important to throw the pilot chute down, but when you throw it is always more important than where you throw it."
I have done a couple of hundred S/L direct bag deployments and supervised (read- watched the deployment video) of a couple of thousand more. I thought the deployments were in general, horrible. The incidence of the d-bag hitting the student, of line twists, and of malfunctions that were induced during deployment (i.e. not built in) was unacceptable compared to IAD. Furthermore the off balance snatch force was a severe impediment to learning during practice pulls.
That said, I think a thorough look at the pros and cons of S/L is better left up to someone with more experience with them than me.

[tkhayes 126]

talk to Joe Chow at Skydive Toronto. We always boasted that IAD was a far better system, but Joe did direct bag with squares for years and is proof that it can work and work well, despite what might be behind it.

I still prefer IAD, but that is what I spent 15 years doing, so of course I am biased.

I would not try direct bag without seeing how someone like Joe does it first and trying to mimic that as closely as possible. no sense in reinventing the wheel.

[riggerrob 558]

TK,

I have worked with both systems on and off since 1982 (S/L) and 1984 (IAD). And I prefer IAD.

My biggest complaint about S/L is the snake's nest on the cabin floor, trying to prevent students from wrapping S/Ls around arms, necks, egs, etc. on the wya out. Then after the last student is gone, you still have to reel in all the S/Ls before you can do a fun jump.

I will admit that S/L is better when dispatching a dozen per pass and when you teach students to exit in a "jab."

[tinay 0]

Thanks for the imput, it is educational.

[skydived19006 4]

I've never been exposed to direct bag SL, and thought that pilot chute with static line assist was the norm. Am I wrong?

I started on static line (with PC), became a SL JM, and I in the 90s, then converted to IAD in the late 90s. IAD is scarier to me, as an open container on the strut (C182) seems to be a bit more likely. We seriously stress to our IAD Instructors to never let go of the PC until the student has let go/left the airplane! Also put in 10 degrees flaps for all IADs.

My list of actual problems with IAD are limited to having a bridle get snagged and bag dropping out as my student was climbing out. I "asked" him to go, he went, I threw, and he got a functioning parachute. With SL, I had a student fall off, but rotate 90 degrees prior to letting go, leaving in a cart wheel. He had the PC bridle running under his arm pit, with bag behind, and PC in front. He pulled his SOS, and got a nice reserve.

I prefer IAD because the student learns with a throw out PC, never has to unlearn/relearn from a rip cord. We don't deal with spring loaded PCs, or switching back and forth from spring loaded to non, etc.

Martin

Experience is what you get when you thought you were going to get something else.

AC DZ

[dragon2 0]

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I've never been exposed to direct bag SL, and thought that pilot chute with static line assist was the norm. Am I wrong?

In The Netherlands, any other method than direct bag is not allowed. So....

ciel bleu,
Saskia

[inextremis 0]

West Point parachute team has used direct bag for at least 40 years, squares since students started using squares. Our students are on a mix of Mantas and Navigators. It's a very fast, very positive deployment, line twists are fairly common but no big deal. We have had no problems with static line entanglement with jumpers, although we have a dream door and water-ski sized step on our Hueys. We collect each static line after each jump and stuff into a sack suspended in the aircraft, so no snakes on the floor--no more than two students per pass. This year we've decided to try IAD--we'll see how it goes, but so far looks good and eliminates some annoying rigging changes to go to BOC. We'll see how that goes.

[riggerrob 558]

I must be old, but when I started jump-mastering, we still had military-surplus rounds, with military-surplus static-lines. Over the years I have dropped students with a variety of S/L (including S/L assisted pilot-chute).
I hated S/L assisted P/C because it gave student just enough time to roll over and grab the pilot chute.

The second-best system is direct bag because it gives clumsy student the least amount of time to entangle.

In the end, I prefer IAD, because it wears out gear the slowest (hint: I do the winter maintenance for three or four or I lost count ... schools) and is the lowest work load for the jump=master.

[docjohn 0]

IAD and Huey Helicopter? Sounds like a recipe for disaster when the p/c hits the tail rotor! Did I miss something?

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

[diablopilot 2]

Maybe the Static Lines are all shorter than the tail boom.

Or maybe they just fly backwards for jump run.

----------------------------------------------
You're not as good as you think you are. Seriously.

[Andrewwhyte 1]

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West Point parachute team has used direct bag for at least 40 years, squares since students started using squares. Our students are on a mix of Mantas and Navigators. It's a very fast, very positive deployment, line twists are fairly common but no big deal. We have had no problems with static line entanglement with jumpers, although we have a dream door and water-ski sized step on our Hueys. We collect each static line after each jump and stuff into a sack suspended in the aircraft, so no snakes on the floor--no more than two students per pass. This year we've decided to try IAD--we'll see how it goes, but so far looks good and eliminates some annoying rigging changes to go to BOC. We'll see how that goes.

I would think the main concern about using IAD from a Huey would be the downdraught pushing the p/c down when the forward speed is too low. I presume that hovering is not normal during personnel deployment but continued success could allow operators to forget that one day in the future.
A stunt man went in in '95 by throwing too soon from a helicopter and wrapping the p/c around his dummy "tandem passenger."
Fly free Kieth.

[inextremis 0]

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IAD and Huey Helicopter? Sounds like a recipe for disaster when the p/c hits the tail rotor! Did I miss something?

It would be extremely difficult, perhaps impossible, to hit the tail rotor of a Huey with a pilot chute. The IAD JM can throw the pilot chute down and away, below the step, almost even with the skid. Our normal flight profile for skydiver exits is NLT 70kts forward speed--nothing even close to a hover, and there is little or no perception of a "downdraft." That puts the tail rotor high, and well to the rear--significantly further to the rear than the tail of a Porter or Cessna, for example--esp the tail wheel of a 180, famous for snagging pilot chutes. When we used static lines, I believe they were 12 feet from the snap to the direct bag, and the attachment point was on a cable high and in the center of the aircraft, not anywhere on the deck. It would take TWO static lines hooked together to get anywhere near the tail rotor. I have about 500 Huey jumps, the Huey is actually a very sweet jump aircraft, and by modern standards, fairly inexpensive to operate--biggest drawback is 10.5K ft MSL ceiling--and the pilots say the control is pretty mushy up there. We take 6 jumpers when full of fuel, 10 when we burn some off.

[skydived19006 4]

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I must be old,...

I agree.

Experience is what you get when you thought you were going to get something else.

AC DZ

[trumm 0]

Hi!
We are using IAD in Estonia for 10 years now.
The most common malfunctions are linetwists from a bad body position in exit.
The most scariest malf. was for me when my student crabbed the pilotchute bridle and it wrapped around her hand, but she managed to solve it. She had like 7 seconds of freefall but she was okey.
I attached some iad exit pics.
The pictures are made in an annual camp in a small estonian island.

[skydiverton2 0]

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I've never been exposed to direct bag SL, and thought that pilot chute with static line assist was the norm. Am I wrong?

In The Netherlands, any other method than direct bag is not allowed. So....

Not forbidden as far as I'm informed, simply not used.
For the first couple of jumps, I would not use a diffent system than direct bag. The chute will open, even when the student grabs the line or exits instable.
For the freefall preparation jumps, the student is able to exit stable. For these jumps IAD can be considered as this allows the student to perform the pulling exercise somewhat more relaxed.

(There are 2 types of IAD. 1 where the PC is in a pouch halfway the line. The other one is only a line with the container closure pin and a break rope that pulls a spring loaded pilot chute. The last one is very scary, as an instable exit might very easy result in a PC entanglement)

Using your droque to gain stability is a bad habid.
.
.
Also in case you jump a sport rig!!!

[tombuch 0]

Humm, I guess we are opening an old thread again!

I made my first jumps with the static line method and old T-10’s way back in the day. I jumpmastered direct bag and pilot chute assist static line jumps for years, and really thought the whole concept of IAD was insane…until I actually tried it.

Back in the day when I learned and when static line training was developed, we used round parachutes. They deploy pretty well with a static line. Squares really don’t. That creates a potential increase in malfunctions, but as much, or perhaps more than that, it generates instability that makes it very difficult for the student to learn proper exit and deployment.

A while back I decided to get my IAD rating as an add-on to my static line rating, pretty much just so I would have it. As part of that process I organized a combined static line/IAD course for our staff instructors who all had at least an AFF rating. To make that work we brought in another instructor to handle the IAD training, and then jumpmastered each other on both systems. I did five actual static line jumps with direct bag and five IAD’s, all in the student position. The key take-away was that when using the static line I was rocking and rolling and unstable throughout the exit and deployment sequence. It was just not possible to feel the air or control my body to any meaningful level. I tried doing some PRCP’s on the static line jumps, but it was nothing at all like an actual rip cord pull. The deployments all had some kind of line twists, and as I watched the parachute try to open I was actually worried at least a few times. The IAD’s, on the other hand, were smooth with very normal openings, and struck me as realistic training events.

If the purpose of the jump is to train the student to become a skydiver, then a well managed IAD program is probably the best of the two. There are issues with potential tail strikes than can be prevented with proper instructor training, and the potential for a student to roll or grab the pilot chute, both of which can also be handled by the instructor.

There are risks and benefits with both systems. If you are struggling with the decision, I suggest you make a few jumps using conventional static line rigging with a square, and then make some more with an IAD deployment. Think about how you will be using the program, who you will be training, and what you expect them to get out of the training.

After experiencing both, my vote (and the vote of every experienced instructor in our dual training camp) was for IAD.

Tom Buchanan
Instructor Emeritus
Comm Pilot MSEL,G
Author: JUMP! Skydiving Made Fun and Easy

[mnealtx 0]

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The other one is only a line with the container closure pin and a break rope that pulls a spring loaded pilot chute. The last one is very scary, as an instable exit might very easy result in a PC entanglement)

That is exactly how I started out my first time around in the mid 90's. We never had anyone get tangled, but it was a fairly short SL, as well - maybe 8 ft.

Mike
I love you, Shannon and Jim.
POPS 9708 , SCR 14706

[livendive 8]

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The other one is only a line with the container closure pin and a break rope that pulls a spring loaded pilot chute. The last one is very scary, as an instable exit might very easy result in a PC entanglement)

That is exactly how I started out my first time around in the mid 90's. We never had anyone get tangled, but it was a fairly short SL, as well - maybe 8 ft.

Yeah, it doesn't sound like any sort of IAD I've heard of, but rather PCA S/L...which is what my student training was too.

I didn't get the thing with the PC in a pouch halfway down the line...it sounds like a combination of the worst parts of S/L and IAD combined.

Blues,
Dave

"I AM A PROFESSIONAL EXTREME ATHLETE!"
(drink Mountain Dew)

[ZigZagMarquis 8]

Some random thoughts from a ways-since retired S/L Jumpmaster...

1) I never did much like IAD. For what its worth, my reasons...
a) Part of skydiving dogma is "Open Door + Pilot Chute out of pocket = BAD, Black Death... now someone goes and invents a training method where Step 1 is exactly that?
b) IMO... and I know what they say about opinions... IAD always seemed to me to be an "easy way out" for Drop Zones that for what ever reason didn't want to bother maintaining both freefall rigs and S/L rigs for student training and/or couldn't be bothered with rigor and diligence required to convert rigs back and forth on a routine basis. Like I said, just me.

2) When it came to S/L, I greatly preferred Direct Bag over Pilot Chute assist. So much so, that one of the reasons I decided to get out of the S/L JM business is because not all DZs I JM'ed at used Direct Bag, others used Pilot Chute assist and it always seemed that no matter how well one trained the students, there was always that one from time to time that tempted fate by sitting on the toilet seat or just about to grab that bridle and wind up with a PC in tow when you put them out on a Pilot Chute Assist S/L rig and make things really scary.

[billvon 2,396]

I've JMed with both direct bag and non-spring-loaded PC assist systems. PC assist gives you a launch similar to IAD; the PC controls the deployment. Some observations:

-During a good exit, PC assist/IAD will give you a better opening. The canopy deploys where it's supposed to. DB forces the parachute to deploy at an angle to the wind, often more than 90 degrees. I've seen the slider driven 2-3 feet down the lines before the canopy is completely clear of the bag; fortunately speeds are low so the opening isn't too brutal.

-During a bad exit, DB is a bit more likely to give you a main canopy without a mal.

-Line twist is far more likely with DB.

-For practice pulls, direct bag doesn't give you enough time unless the student _really_ rushes things, which can be counterproductive.

-DB tends to beat the airplane up a little more.

[BrianM 1]

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-During a bad exit, DB is a bit more likely to give you a main canopy without a mal.

During a bad exit, an IAD JM has the option of hanging on to the PC until the canopy is out of the bag, producing the same result as DB SL.

"It's amazing what you can learn while you're not talking." - Skydivesg

[ZigZagMarquis 8]

Yeah, and a JM could "short line" a student on a SL jump too, but, personally, I never thought that was a good idea either.

[AdD 1]

I have a few seasons of SL dispatches and maybe 10 IAD loads, I think SL is preferable because students do some really F'd up S*%* on exit sometimes. Keep in mind most of them were from a 206U, I do like IAD for the 182 hanging exit because it's fairly predictable.

Life is ez
On the dz
Every jumper's dream
3 rigs and an airstream