Another Exit Order Question: Hybrid

[azureriders 0]

Our DZ follows the same basic exit order that most on here seem to agree with. RW largest to smallest, FF largest to smallest, AFF, Tandems.

A load from this weekend, in the order of exit 1) RW four way round, 2) solo belly flyer, 3) Hybrid including 6 or 7 belly flyers.

I realize that hybrid belly flyers arch hard and fall fast in sake of their FF counterparts, but do they truly fall faster and therefore have less drift than the solo that went ahead of them. (I don't think so)

Does the fact that they had more belly flyers slow them down more than the RW four way and therefore they should have went first (I still don't think so)

IMO the correct order would have been 1)RW four way, 2) Hybrid 3) Solo Belly, but then again I don't know enough about the fall rate of a Hybrid to say this for sure ergo my questions.

More info: Jump run was into the wind. I was in the first group so I felt safe no matter. I knew we had more drift than the solo and even if the hybrid should have gone first I could not see them drifting all the way over the solo and to us. The hybrid was also packed with experience, a lot of which I have the utmost respect for and no doubt in my mind they gave a good separation (although I was gone by that time so who can say for sure)

I have learned a lot from a few similar threads in the past and Kallend's model is great. I would appreciate any input on this to further my knowledge.

[billvon 2,402]

To get best advantage of the greater separation you get when you have faster fallers out last, it should be:

RW
hybrids
freefly

[bob.dino 0]

In my limited experience, hybrids fall at 140-160mph, with 155-160mph being the most common. 20-way hybrids rock

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[azureriders 0]

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RW
hybrids
freefly

I know and agree with this, and also that larger groups fall slower therefore the largest to smallest within each discipline. I guess my question was could one larger group of one discipline overlap fall rates with a small group of another discipline?

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hybrids fall at 140-160mph, with 155-160mph being the most common

If that be the case I stand corrected already as I don't believe the solo belly flyer was falling nearly that fast and the exit order was correct as it was.

[packing_jarrett 0]

how come DZ just do jump-run crosswind. That would eliminate the exit order problem right?

Na' Cho' Cheese

[billvon 2,402]

>how come DZ just do jump-run crosswind. That would eliminate the
>exit order problem right?

Yes. Problems are:

1. It's harder to spot
2. You have to leave pretty quickly to get everyone out on one pass; it's like separation for zero uppers.

[matthewcline 0]

How about a "cross/up-wind" exit?

I have used it on CH-47's and it seemed to work pretty good. The alt was 14K, A/C airspeed was 100kts and the load had the usuall mix of RW, Hybrid, VRW, Student/AFF and tandems with Video.

An Instructors first concern is student safety.
So, start being safe, first!!!

[billvon 2,402]

> How about a "cross/up-wind" exit?

That requires people to either do trigonometry or at least understand it - and skydivers generally don't do trigonometry. It also requires RW out first, like an upwind jump run (at least if you want the best possible separation.)

If you're going to program the GPS and do the math and all, then a curved jump run might be the ticket. Eloy has experimented with these, with good results. You end up leaving too much time as the last people get out, but everyone ends up closer to the DZ so it's not as big a deal.

>The alt was 14K, A/C airspeed was 100kts . . . .

A 100kt airspeed fixes many ills, since it's difficult to get out fast enough to cause a separation problem.

[CornishChris 5]

Hybrid Dave? Is that you?

CJP

Gods don't kill people. People with Gods kill people

[bob.dino 0]

I was waiting for that, though it was Oli I was expecting to chime in .

[matthewcline 0]

trigo what? is that what I was doing?

I only used it to avoid the " we are always hosed and out so long" complaints. We happened to be able to get 30 (+ or -) out in 1 pass each time and have planty of seperation and a good drift line.

An Instructors first concern is student safety.
So, start being safe, first!!!

[br0k3n 0]

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Hybrid Dave? Is that you?

How did you beat me to that Parsons... gutted

Oh HD (hybrid Dave) is this your work (goto 3mins 37secs)

-----------------------------------------------------------
--+ There are 10 types of people in the world: Those who understand binary, and those who don't.. --+

[milkybar 0]

Consider break-off altitudes, and deployment altitudes: Consider experience level of jumpers on Hybrid, jumpers following hybrid [new freeflyers = horizontal drifting]
Seperation is paramount: Many times organizers will alter the exit order to ensure safe separation. A hybrid has the potential to drift horizontally.
A good organizer takes many things into account to determine the safest exit order.
If I doubt the organizer's judgement or those in his/her's group, I state I will be deploying higher than them and stick to the plan, enjoy the extra canopy time, and the uncluttered airspace as I come into land.

As with most things in skydiving there are many variables to take into account.

Disclaimer: All the above is the opinion of an idiot.
Signed: Ab Normal

[davelepka 4]

The biggest problems with hybrids is that the fall rates vary greatly from jump to jump. If ti build fast, and is solid, it's closer to a freefly jump. If it builds slow, and the hangers cork, it's back to belly speed.

Separation from drift is all related to time in freefall, so the fall rate becomes an issue. The best slot is inbetween the last RW and first freefly group, so what ever happens they're good.

[popsjumper 2]

Quote

...
>The alt was 14K, A/C airspeed was 100kts . . . .

A 100kt airspeed fixes many ills, since it's difficult to get out fast enough to cause a separation problem.

Uh....I assume you are considering 0kt uppers at exit altitude here.

Other than that, one would be considering ground speed rather than airspeed along with winds aloft at lower altitudes.

Fell free to correct me if I'm wrong.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[billvon 2,402]

>I assume you are considering 0kt uppers at exit altitude here.

I'm considering all uppers. The faster the airspeed of the plane, the faster its groundspeed as well. An Otter flying 80kts is always going to require greater separation times than a King Air flying at 100kts.

[TheDonMan 0]

Thats not true..... An otter going 80kts with 0kt head wind will have the same ground speed as a kingair flying at 100kts air speed with a 20kts head wind. When determining separation from groups you should be looking at ground speed and should have around 1000ft separation between groups based of the ground speed not the air speed.
The air speed is a constant..... An Otter will always have the same air speed on jump run just to stay in the air. that does not mean that the ground speed will always be the same. I have been on some Jump runs that the uppers were so strong that we needed 20 seconds of separation because our ground speed was about 35 kts.
The plains air speed was 80 kts.

The world is full of willing people, some willing to work, the rest willing to let them.

[billvon 2,402]

> An otter going 80kts with 0kt head wind will have the same ground
>speed as a kingair flying at 100kts air speed with a 20kts head wind.

Right. But in ANY GIVEN WIND the faster plane has less problems with separation. Which means that any given DZ, the faster planes will have fewer separation problems than the slower planes. Greater airspeed can help people who don't understand separation to get separation anyway.

[kallend 1,632]

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The air speed is a constant..... An Otter will always have the same air speed on jump run just to stay in the air. .

NOT TRUE! Try jumping from an Otter in trail behind a CASA on a multi-plane formation.

...

The only sure way to survive a canopy collision is not to have one.

[TheDonMan 0]

That's because the CASA need more AIR speed to stay in the air... When flying in formations the air speeds for all the planes need to be the same as the plane that needs the greatest amount of AIR speed to keep from falling out of the sky. Thus the Otter will actually fly faster to keep up with the CASA when in actuality is can fly a lot slower and still stay in the air.

The world is full of willing people, some willing to work, the rest willing to let them.

[pilotdave 0]

I think his point was that airspeed on jumprun isn't constant for a given aircraft. There may be a nearly fixed minimum jump run airspeed, but pilots won't always fly at that minimum. And of course that minimum includes some margin... the pilot doesn't fly jumprun at the minimum controllable airspeed (the airspeed needed to "stay in the air").

Dave

[kallend 1,632]

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I think his point was that airspeed on jumprun isn't constant for a given aircraft. There may be a nearly fixed minimum jump run airspeed, but pilots won't always fly at that minimum. And of course that minimum includes some margin... the pilot doesn't fly jumprun at the minimum controllable airspeed (the airspeed needed to "stay in the air").

Dave

"Always" is very difficult to justify.

...

The only sure way to survive a canopy collision is not to have one.