Freefalling Helmets

[JohnRich 4]

This weekend a lady skydiver forgot to tighten her helmet strap before exit. The helmet stayed on her head in freefall, but popped off upon parachute opening shock. After landing, considerable time with several people was spent searching for the missing helmet, with no luck.

A few hours later, I noticed a helmet laying in the grass near the end of the runway, so I landed next to it and retrieved it. Laying about three feet away was the Pro-track which had popped out of the earpiece on impact. The missing helmet was found!

Between the helmet and the Pro-track, that was about a $450 recovery. I got some free beer out of the deal at the end of the day.

The helmet landed on soft mushy ground that had been soaked with rain for days, and was undamaged, except for one broken plastic bolt at the visor pivot point.

And now, the interesting part. I turned on the Pro-track to see if it still worked, and it did. The display for the last jump showed 109 seconds of freefall from 13,000 feet, with a 2nd half average of 53 mph.

So now we know the terminal velocity of a freefalling helmet!

[NWFlyer 2]

Those Protracks are hardy things! I bought mine off a guy who used to jump at my DZ. He said it wasn't working but that he'd refund my money if I sent it into L&B and they weren't able to fix it or replace it. Of course L&B sent it back working perfectly... then he confessed that he'd never used it; he found it in a field.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[JohnRich 4]

Story time!

I have lost several Protec helmets myself in the air.

On one occasion I was rear-floating an exit from an Otter door, and my helmet floated up off my head and disappeared over the tail of the plane. A year later, a student hiked back in from landing way out in a cow pasture, and had my lost helmet in his hands. The cows had eaten the foam lining out of the inside of the helmet, and the helmet was scarred with teeth marks.

On another occasion, my helmet came off in freefall, and dozens of seconds later after opening my parachute, my helmet came falling past me right smack in front of my parachute, barely missing me. That was convenient, and I followed it down to the ground, to find it scuffed, but undamaged.

In my student days, when Protecs used to have a chin strap that snapped to the outside of the earpieces, I had my deploying risers strip one side of the strap off the snaps, popping the helmet off my head. I circled while watching it fall to the ground to keep a bead on where it was going to land. I was amused by how the helmet would tilt every few seconds, causing it to slide first one way, then another, through the sky. The helmet went into heavy woods, and when I hiked in to try and find it, I encountered a giant diamondback rattlesnake. The helmet remained lost.

And finally, I had a jump where apparently I forget to attach the chin strap, and the helmet was trying to float up off my head in freefall, and I could feel it happening. I put my left hand on top of my head and held the helmet in place. This is when I learned that it is very difficult to do sequential RW with one hand on top of your head. So the dive didn't go too well, but I saved the helmet.

[billvon 3,109]

During one of the 300-way attempts, severe cold resulted in icing of faceplates. Something like 30 people just took their helmets off to allow them to see. The rain of helmets later was fun to watch, and most were recovered without much damage. (Lesson learned - different helmets have _very_ different fall rates, and some of them apparently like to track.)

[monkycndo 0]

I came close to losing my helmet last year at Dublin. I didn't fully engage the neck strap after putting my goggles on just prior to exit. Dove out the back of the AC and felt something hitting my throat. Luckily, since I was in a dive, the helmet didn't come off. While still diving to the formation, held the helmet with one hand and connected the fastex clip with the other. Made my slot, but just barely.

50 donations so far. Give it a try.

You know you want to spank it
Jump an Infinity

[freakflyer9999 1]

I was standing in the landing area gathering my canopy when I heard a thud behind me. A student's protec was lying about 10 feet away.

Later I overheard a student telling someone that he couldn't find his helmet to turn back into the DZ. After a few questions he sheepishly admitted to losing it in freefall.

[BlueSBDeath 2]

I lost an Nvertigo in Hawaii, several days later a jumper asked me if this helmet was mine, he reconized some of the stickers, it had been brought to him by a local surfer who found it on the beach. The ProTrack was gone, but the helmet was fine, except I was getting sand out of it for a long time!!

Arvel

BSBD...........Its all about Respect,

USPA#-7062, FB-2197, Outlaw 499

[VincentVL. 0]

So what does a freefalling helmet do to the head of the person on the ground it impacts?

Is it "oh he got hit hurhur " or more of a female-witness-crying-male-witness-wtf'ing kind of thing...

[Yossarian 0]

id imagine it would leave the same kind of bruise as any other solid round object hitting you in the face at 60mph... bag of frozen peas anyone...?

[cpoxon 0]

Here is a graph of the data I downloaded from my Bonehead Mindwarp, d-box, PC1 and ProTrack that went in!

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[steve1 5]

Freefalling objects can be down right dangerous, but I don't think I've ever heard of an incident where someone was hurt.

In the army we often jumped equipment. Sometimes it was kind of scary to be on the ground when jumpers were exiting in a mass formation above you. I've seen more than one rucksack crash into the ground. It wasn't unusual to see a helmet fall off. Everything is carefully checked by jumpmasters and riggers, but it still happened.

I jupmastered and rigger checked one stick of jumpers. One of these guys later came up to me, really pissed, because he lost his rucksack. Come to find out, the buckles were too large for the quick release straps (that attached the rucksack to him). So, it wasn't my fault after all.

It was often fun to walk across a sport DZ in the 70's. You'd often find old rip cords and kicker plates. (I wonder how many new jumpers have a clue what a kicker plate is? I'll bet they might have antique value today)....Steve1

[JohnRich 4]

Quote

Here is a graph of the data I downloaded from my Bonehead Mindwarp and ProTrack that went in!

Very interesting. You must have been doing a head-down dive to be at 170 mph for most of the dive? And then you opened at about 3-grand and the helmet popped off? It looks like the helmet decelerated from 170 mph to about 50 in just 8 seconds, and then remained at 50 mph until impact.

Neat graph. Thanks for sharing it.

[Orange1 0]

Quote

(I wonder how many new jumpers have a clue what a kicker plate is? I'll bet they might have antique value today)....Steve1

i'll bite... what is it?

Skydiving: wasting fossil fuels just for fun.

[fastphil 0]

Kicker Plate is a small, circular, frisbee looking plate thingy that packs between the pilot chute and canopy of reserves to prevent the spring from burrowing into the canopy. It is not attached to the rig and fall free upon reserve deployment.

We once lost the rear luggage door off the Spaceland Twin Otter on jump run, it potatoe chipped down from 12K in the field next to the runway. Dave Boatman was some kinda pi$$ed, and, of course, no one knew nothing about the cause (Dave had machine guns). Guess the latch may have been opened on the ground while loading.

[bozo 0]

In the mid 80s before camera helmets became so compact, a buddy of mine was jumping his brand new 2000 dollar camera and helmet for the first time.
He was going to film a four way for us out of our Queenaire. He crawled out rear float ,we exited.
He came in and docked.....without the helmet.
He had forgotten the chinstrap and he lost that heavy bugger as soon as he left the plane. Luckily the spot was good...the helmet was found literally exploded on a dirt road a couple hundred yards from the peas.
Pieces and parts were scattered for ten yards diameter.

bozo
Pain is fleeting. Glory lasts forever. Chicks dig scars.

[Travman 6]

A girl at my DZ lost her Z1 on a funnelled 4-way exit. It was quickly recovered. Once she put a new visor in, it was good as new

[piisfish 140]

Quote

(Lesson learned - different helmets have _very_ different fall rates, and some of them apparently like to track.)

do you suggest adding weights to helmets to match their fallrates

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[cpoxon 0]

Quote

Quote

Here is a graph of the data I downloaded from my Bonehead Mindwarp and ProTrack that went in!

Very interesting. You must have been doing a head-down dive to be at 170 mph for most of the dive? And then you opened at about 3-grand and the helmet popped off? It looks like the helmet decelerated from 170 mph to about 50 in just 8 seconds, and then remained at 50 mph until impact.

Neat graph. Thanks for sharing it.

Pretty much, yes.

Found a previous post which had an even better one:

from a ProTrack from Didier Moinel Delande who was training for a Speed Skydiving jump when he lost his Oxygn. 200 mph decceleration in 10 seconds

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[JohnRich 4]

Quote

from a ProTrack from Didier Moinel Delande who was training for a Speed Skydiving jump when he lost his Oxygn. 200 mph decceleration in 10 seconds

Wow!

And there's that 50 mph number again. So this is three helmets in a row tracked in freefall at between 50 and 55 mph. So that is shaping up to be a fairly accuract number.

Thanks for providing that link.

[Orange1 0]

Quote

This weekend a lady skydiver forgot to tighten her helmet strap before exit. The helmet stayed on her head in freefall, but popped off upon parachute opening shock.

Thanks for this thread... it came to mind when in freefall yesterday i noticed my strap flapping against my visor Held on to the helmet at opening and saved it - brand new Z1 with a protrack inside, wouldn't have been fun to lose it. Lesson learnt.

Skydiving: wasting fossil fuels just for fun.

[peggs82 0]

Quote

Freefalling objects can be down right dangerous, but I don't think I've ever heard of an incident where someone was hurt.

This past august, at skydive chicago, there was a student who cut away and tossed her handles. The reserve handle hit a fisherman... Never heard what happened to him...

[kallend 2,146]

Question to anyone who has witnessed a freefalling helmet - did it fall in a stable attitude, or did it tumble, spin, or oscillate as it fell?

...

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

[Zing 2]

I've seen two. Watched one go by the Porter I was flying. Saw another one go in from the ground. Both stayed more or less top of the helmet toward the ground, but they do rock back and forth and appear to slide around rather than plummeting straight down.

Zing Lurks

[JohnRich 4]

Quote

Question to anyone who has witnessed a freefalling helmet - did it fall in a stable attitude, or did it tumble, spin, or oscillate as it fell?

The few I've witnessed fell top-down. They did not spin or tumble. But they do tilt a bit back and forth on axis, and that causes it to slide away from the tilt - like a leaf dropping from a tree, and sliding back and forth as it falls.

[pilotdave 0]

This one didn't do so well: http://pilotdave.smugmug.com/gallery/2408672/1/126195042/Medium.

Ok, it was found the other day in the middle of a street a long time after it was lost (not sure how long, but months I think). And it had obviously been hit by a car or farm equipment.

I saw a Z1 that landed right on the DZ once... no problem other than a cracked visor. It was knocked off on exit. The first 2 jumpers in that group landed, started to talk about the jump, and then it came crashing in right in the landing area. Pretty amazing that it fell so slow.

Dave