Parachute Entanglement

Guest Discussion
21

Jim,

I disagree, but then that’s what keeps life interesting.

The deployment of the chute after a successful ditching may be worthwhile and offer some survival benefits. At worst, it would likely counteract the nose down submergence of the aircraft for a brief time, opposite reactions and all that. That might be a critical few seconds that can be gained.

WRT the effects of the chute in the water, it will act as a drogue, at worst, and sea anchor at best. This might help counter the nose down submergence of the aircraft for the simple reason that most aircraft would float if their center of balance wasn’t so far forward (some do anyway, but that is the exception). In a number of cases, aircraft have floated for hours when the occupant(s) have climbed onto the eppenage to counter this. Any force that helps counter the tail coming up would be an advantage. The chute acting as a drogue or sea anchor might well accomplish that.

Assuming it remains afloat, the advantage is that the survivors may have a dry place to await rescue, if they don’t already have a raft, and even if they have a raft, the considerable added viewability afforded by the aircraft and chute in the water will be a significant advantage when SAR comes looking.

WRT blowing a hole in the aircraft. This is on the top of the aircraft and is unlikely to have even the slightest adverse effect on the buoyancy unless seas were of such a nature that the aircraft would likely sink anyway.

WRT shooting the rocket off when there is fuel on the water, I’d suggest that common sense would suggest you might not what to do it then and any such leakage would be readily apparent under most conditions. Moreover, fuel leakage in GA ditching incidents while still afloat does not appear to be much of an issue. Most fuel leakage occurs, when it does, after sinking.

WRT, the chute in the water being a safety hazard, I think you are way off base. If the aircraft remains floating because of this effort, the survivors are going to be on or in the aircraft, or in a raft attached to the aircraft, in either case it’s not an issue. If the aircraft sinks, its not an issue, the chute goes with it. If the helo arrives for a pickup, with rare exception U.S. SOP is to deploy a swimmer away from the survivors who will swim to the survivors. He will pull the survivors one by one to the pick-up point and the helo will return for pick-up, again, away for the object in the water, be it a raft, boat, whatever. It is extremely rare for a helo to do a pick-up from a relatively small object in the water except when there is no alternative (very severe injury for example). In any case, a fully wetted and partially submerged chute isn’t a hazard for a helo anyway (BTDT on one offshore SAR exercise).

From my POV, the potential advantages for survivors in improving their situation far outweigh any possible disadvantages, which for the reasons stated, I believe to be minimal at worst.

Finally, while this entire suggestion is based on conjecture, it is also based on a good understanding of the potential risks and rewards and the dynamic effects involved based on my experience and such data as I could gather. Anyone who ditches a Cirrus at this point is already performing as a test pilot, though they at least have lots of successful conventional ditchings in single engine fixed-gear singles to guide them. Anyone ditching using CAPS is really a test pilot with little reliable data to rely upon since Cirrus have declined to provide any data on the forces that are likely to be encountered in a ditching.

Doug Ritter

22

Doug: Thanks for clearing this up and glad to see you keep an eye on the site.

Marty

23

Doug,

I’m curious about your experience in whether its better to keep doors open before a water landing or closed until after landing. I certainly can come up with arguments on both sides.

What’s your opinion?

Eric

24

Doug, I couldn’t disagree with you more.

In reply to:

The deployment of the chute after a successful ditching may be worthwhile and offer some survival benefits. At worst, it would likely counteract the nose down submergence of the aircraft for a brief time, opposite reactions and all that. That might be a critical few seconds that can be gained.

Are you honestly saying the force of the rocket itself will somehow hold the nose up? Sorry. Don’t buy that for a second.

In reply to:

WRT the effects of the chute in the water, it will act as a drogue, at worst, and sea anchor at best. This might help counter the nose down submergence of the aircraft for the simple reason that most aircraft would float if their center of balance wasn’t so far forward (some do anyway, but that is the exception). In a number of cases, aircraft have floated for hours when the occupant(s) have climbed onto the eppenage to counter this. Any force that helps counter the tail coming up would be an advantage. The chute acting as a drogue or sea anchor might well accomplish that.

Again, “might.” A weak case at best, and who’s to say which way the plane will drift initially? Toward or away from the chute? Nose or tail first? And, unlike a sea anchor, the parachute isn’t attached to a single point and therefore its effectiveness is hardly a given.

In reply to:

Assuming it remains afloat, the advantage is that the survivors may have a dry place to await rescue, if they don’t already have a raft, and even if they have a raft, the considerable added viewability afforded by the aircraft and chute in the water will be a significant advantage when SAR comes looking.

Again the speculation about whether or not floating will be improved is offset by the certainty that you’re in more peril if it sinks, which is likely.

In reply to:

WRT blowing a hole in the aircraft. This is on the top of the aircraft and is unlikely to have even the slightest adverse effect on the buoyancy unless seas were of such a nature that the aircraft would likely sink anyway.

Could be right on this one, but I can easily envision it sinking faster with water lapping into that cavity.

In reply to:

WRT shooting the rocket off when there is fuel on the water, I’d suggest that common sense would suggest you might not what to do it then and any such leakage would be readily apparent under most conditions. Moreover, fuel leakage in GA ditching incidents while still afloat does not appear to be much of an issue. Most fuel leakage occurs, when it does, after sinking.

I see, so now the procedure is ditch, evaluate the sea state to see if the hole will be a problem, check for fuel leaks to see if the rocket flame will be a problem, then decide whether to pull the chute. Well, I’d rather spend my time getting squared away as to my raft and life vest, free from the worry of being pulled under by a sinking plane.

In reply to:

WRT, the chute in the water being a safety hazard, I think you are way off base. If the aircraft remains floating because of this effort, the survivors are going to be on or in the aircraft, or in a raft attached to the aircraft, in either case it’s not an issue. If the aircraft sinks, its not an issue, the chute goes with it.

Unless you’re entangled in it, or it snags you on the way down, in which case you go with it too. I have a hard time conjuring up an image of the pilot and passengers sitting comfortably in their floating aircraft, or magically being transported into their raft, if they have one (I know how hard they are to get into). There’s likely going to be a lot of thrashing around in the water before things settle down, one way or the other, and I’d rather not have a chute, risers, and shroud lines nearby with all that going on.

In reply to:

If the helo arrives for a pickup, with rare exception U.S. SOP is to deploy a swimmer away from the survivors who will swim to the survivors. He will pull the survivors one by one to the pick-up point and the helo will return for pick-up, again, away for the object in the water, be it a raft, boat, whatever. It is extremely rare for a helo to do a pick-up from a relatively small object in the water except when there is no alternative (very severe injury for example). In any case, a fully wetted and partially submerged chute isn’t a hazard for a helo anyway (BTDT on one offshore SAR exercise).

I know the Navy can cope with it (I was a naval aviator) but why complicate things for them?

In reply to:

From my POV, the potential advantages for survivors in improving their situation far outweigh any possible disadvantages, which for the reasons stated, I believe to be minimal at worst.

So why did I spend innumerable hours disentangling myself from parachutes when their danger is “minimal at worst?” I think the Navy knows a thing or two about survival at sea. And, as I said before, I personally watched two men die from this “minimal” danger.

In reply to:

Finally, while this entire suggestion is based on conjecture, it is also based on a good understanding of the potential risks and rewards and the dynamic effects involved based on my experience and such data as I could gather. Anyone who ditches a Cirrus at this point is already performing as a test pilot, though they at least have lots of successful conventional ditchings in single engine fixed-gear singles to guide them. Anyone ditching using CAPS is really a test pilot with little reliable data to rely upon since Cirrus have declined to provide any data on the forces that are likely to be encountered in a ditching.

I agree. That’s why I’d urge conservatism, not novelty.

Joe

25

In reply to:

Anyone ditching using CAPS is really a test pilot with little reliable data to rely upon since Cirrus have declined to provide any data on the forces that are likely to be encountered in a ditching.

Well, they have provided enough data to make a decisions on whether to use CAPS for a water arrival. That data is the published fact that you will be travelling downward at 20 MPH (as if dropped from 13 feet), and that the seats are designed to absorb impact in that specific direction. Contrast this to impacting the water conventionally at at least 60 kts in a direction in which you will flail. Given the exponential deceleration difference between these two choices, I cannot fathom (sorry!) why anyone would choose to ditch conventionally.

If I may repeat a snippet from one of my previous Member’s forum posts on the subject:

The more I think about this, the more I am convinced that the 'chute is the way to go for ditching in all cases. Splashing down into the water at 20 MPH, guaranteed sunny-side-up, is likely to be better than even a “perfect” conventional ditching at 80 MPH. (Sixteen times better, actually. Remember, KE varies as the square of the velocity.) You have the 23G seats working vertically as intended, much less risk from flying objects in the cabin, and more time to prepare the occupants, get the survival gear ready, and transmit a mayday call.

I think those that fear the “cement” aspect of the water surface are comparing it to a Golden Gate Bridge leap. But the velocities, and therefore deceleration, are vastly different. As I said before, none of us would think twice about jumping off a 13 foot diving board, even if one had to do a “belly flop,” if it was going to save your life. Clearly, water only assumes cement-like qualities when you encounter it with missile-like velocities.

26

Well, like I said, YMMV. I leave it to the members to decide whose conjecture they find more plausible. It appears that you are not about to be dissuaded from your strongly held opinions regardless of the facts or my experience and I respect your right to hold those opinions, no matter how wild and paranoid I might find them. :slight_smile: It’s not often I run into someone more paranoid than myself since that’s pretty much the basis for my business and avocation, congratulations–I think. :slight_smile:

Doug Ritter

27

And another thing, Doug.

All this talk of the long kevlar straps keeping the chute well away from you is, I think, dead wrong. I seriously doubt that the rocket force alone will rip the straps from the fuselage. (In a “normal” deployment the drag of the the opening canopy does that, not the rocket.) My guess is that the shroud lines and risers will be right there with you after a static deployment. The picture you included shows, I think, the white shroud lines extended by the rocket, not the black kevlar straps.

Joe

28

Well, I agree that others can make their own choices. But I’m not paranoid my man, I’ve seen how much confusion and uncertainty happens in a ditching situation (albeit only in training, but very realistic, in-the-open-water, hands on training).

In the opinion of the Navy, the single greatest hazard after water entry in an ejection or bailout is the parachute, either dragging you under, entangling you so you can’t swim, or pulling you face first along the surface in high winds. To blow that danger off with speculation about marginal, postulated, theoretical, “benefits” that may or may not be realized is irresponsible for someone in your position.

I prefer to rely on the experience gained in blood over the years rather than armchair speculation.

It’s just this kind of “my airplane is different so I know better” attitude that may well be at the root of the Cirrus’ poor safety record.

Joe

29

In reply to:

All this talk of the long kevlar straps keeping the chute well away from you is, I think, dead wrong. I seriously doubt that the rocket force alone will rip the straps from the fuselage. (In a “normal” deployment the of the the opening canopy does that, not the rocket.) My guess is that the shroud lines and risers be right there with you. The picture you included shows, I think, white shroud lines extended by the rocket, not kevlar straps.

Joe,
I don’t want to prolong this debate… but I happen to know otherwise on this point, from experience when I participated in CAPS testing at Cirrus’ facility in Duluth in March last year. The photos below show that when the CAPS was fired in near-calm wind conditions from a stationary airplane, the rocket force alone did in fact (a) displace the parachute as far away from the airplane as the risers would allow, and (b) rip the straps from the fuselage.

30

I concede this small point.

Thanks.

Joe

31

In reply to:

The photos below show that when the CAPS was fired in near-calm wind conditions from a stationary airplane, the rocket force alone did in fact (a) displace the parachute as far away from the airplane as the risers would allow, and (b) rip the straps from the fuselage.

Mike,

In that test wasn’t the chute rigging modified to remove the delay squibs? I thought the shrouds are held inside the chute compartment after the initial rocket launch, and the side straps aren’t free to release until the delay squibs fire?

-Curt

32

There’s something of “apples” and “oranges” in this thread. There is a very significant difference 'tween a person-chute and a CAPS-chute. What applies for the former may well not apply for the later.

33

OK! Since we have been debating this based upon conjecture, theory, transposition and pure fantasy.

Therefore, to settle this once an for all, I propose:

  1. We ask JT Helms if a parachute in the water would affect his search and rescue methods. (He is a ‘retired’ rotor head and arguable an expert.) IMHO, SAR would not hover directly over the downed aircraft as the rotorwash would interfere and you always want the cable to be grounded before it is touched by anyone on the ground or water. Being off to the side reduces the chance of a static shock and affords better visibility to the aircrew.

  2. Since no one has ever ditched a Cirrus, and sir Mike has already been a “CAPS test pilot,” how about we get him to test ditch the airplane?

I can think of only 3 or 4 “Ney” votes, so why don’t we set it up for the Bay off of Ocean Reef Club. Richard would be happy to host the event. the water is very warm and usually calm. Mike, you’ll also get to break-in your new digital camera!

What a win-win-win situation!!!

Marty

34

One more try since apparently the electrons got lost on the way.
I must take issue with your brush off of my comments as “armchair speculation.” I challenge you to find anyone who has invested more time and resources investigating the subject of General Aviation ditchings or who has spent more time being turned upside down and inside out in both military and civilian ditching simulators of every description. My suggestions are based on my well-founded experience and research, I don’t even own an armchair.

35

In reply to:

Ditching General Aviation aircraft remains, despite old wives’ tales to the contrary, one of the very safest and survivable of emergency landing procedures.

I agree. And in how many of these benign scearios was a parachure involved? Hint: None. Let’s keep it that way.

Joe

36

In reply to:

There is a very significant difference 'tween a person-chute and a CAPS-chute.

I agree that a person chute poses a greater danger, initially, than a CAPS. But a chute nearby in the water is a chute nearby in the water. They all pose a threat. The CAPS is a new concept, but that doesn’t mean we should throw away hard-earned lessons from conventional parachutes without some very serious thought.

Joe

37

Mike;
I question for you: When you did the test of the CAPS in Duluth, after the chute was deployed, was there any “drag” effect on the airplane after deployment? Clearly when a PERSON uses a chute, he will de dragged all over the place after landing if there is a wind as the effect of the chute pulls a greater weight than the that of the person.
Was the Cirrus dragged around at all? Give the probable light wind of the day, was there any significant “pull” on the plane?
I think the answer would help clear up any perceived danger of a chute in the water attatched to a Cirrus.

38

Yes, and here was my reply to your lost post which included the statement, which I agree with, that GA ditchings are usually benign:

In reply to:

Ditching General Aviation aircraft remains, despite old wives’ tales to the contrary, one of the very safest and survivable of emergency landing procedures.

I agree. And in how many of these GA ditchings was a parachute involved? Hint: none.

Joe

39

My opinion is doors unlatched and secured open. I understand that with the Cirrus if you open the door and then move the handle to the locked position that will prevent it from latching, which is more effective than sticking an approach plate book in the door. I was warned that there might be some chipped paint afterwords, but sometimes you have to make some compromises. :slight_smile:

Most of the pilots in ditchings I have investigated have opened the door with no adverse issues. Most have been conventional construction, of course. Looking at the design of the Cirrus and its doors, I doesn’t seem to me that there’s enough added structural rigidity provided to counter the possibility of the door being jammed, which you definitely would like to avoid. Quick and prompt egress is a very high priority IMHO.

Cirrus provides no data with which to make a fully informed decision in this regard. Having said that, the Cirrus does have two primary exits, so the danger of a jammed door is lessened compared to some others with a single primary egress path.

If flipped, unlikely, but it can happen, you want water to come in so pressure equalizes and you can more easily open the doors. Starting with the door ajar will assist with that and presents less problems, IMHO, than breaking a window.

Doug Ritter

40

In reply to:

In that test wasn’t the chute rigging modified to remove the delay squibs? I thought the shrouds are held inside the chute compartment after the initial rocket launch, and the side straps aren’t free to release until the delay squibs fire?

Curt,

I believe that for that particular test (N109CD), no modifications were made; but in the next test (when I actually fired the CAPS), the front risers were disconnected, to avoid the damage to the side skin.

Not sure about the effect of the squibs. My understanding was different – I thought that they merely hold some part of the thing (risers?) folded until a few seconds after launch, but that the side straps do in fact rip out practically right away. I’d like to get clarity on this point, and I’ll pursue it (if my aging memory will support this thought until tomorrow! [;)])

  • Mike.