question about hop and pop from 18K

[377 21]

Although I have been jumping since 68 (still active) I know zero about CRW or high altitude openings so please forgive what may seem like ignorant questions.

I want to do some ham radio long range communications from under canopy so I want a lot of time under canopy and a high antenna altitude.

I weigh 214 and jump a Triathlon 210. I'd like to do a hop and pop from 18K. What do I need to know/learn etc to make it safe? Is O2 advisable if flying a canopy that high? Any special precautions/techniques on deploying that high?

I jumped from 18K last weekend, no big deal, but it was a normal jump not a hop and pop. I have also done a couple of jumps from Mullins King Air at WFFC from about 23K.

I figure the CRW dogs know all about this stuff so that's why I am posting here.

Thanks for any help and advice.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[BillyVance 34]

I've done many recreational crw jumps from 15,000 feet out of Mullins' King Air. An extra 3000 feet from that point may not seem like a big deal but it is. The base on the 100 way world record were jumping with supplemental oxygen, IIRC.

Just pack your Triathlon to give you a nice smooth opening. I roll the outer 3 cells into the nose on mine.

I don't have any experience jumping with an oxygen bottle, but like you, have made a couple of 23,000 feet jumps from Mullins King Air using on-board oxygen before exit.

Another thing.... dress warm. And hope you have padded leg straps.

"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

[LouDiamond 1]

You're in luck as I happen to have spent a good deal of time doing HAHOs from 18k and higher testing out a new oxygen mask. I'm assuming you don't have access to the same military grade O2 equipment that I do nor will you be jumping with supplementary O2?

Setting the O2 issue aside for a moment, my other questions are what type of aircraft will you be using to get to 18K and what is the surface temperature where you plan to be jumping at right now?

Once I know those things I can better tailor the answer to some of your questions.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[TVPB 0]

I was fortunate to be on the trail CASA (aircraft #2) load for the 100 ways. = 18000 ft exit.

It was not a major drama r.e. oxygen, openings, and/or cold for our loads. We had 6 total attempts at 100 ways. On the actual official record jump, we ran out of oxygen about 10 minutes before exiting. No one on our load was affected adversely.
Openings were OK. There were some minor efforts in reducing opening shock

However, there were reports of minor affects r.e. ox/hypox on the lower 16000 & 12000 loads as we did get held up a bit. This indicates how variable affects can be amongst people. Hence, personal physiology is a key part of determining how you will be affected. It should also be noted that the bigger people were on the higher loads and smaller people on lower loads (on average).

I think Kirk W. VANZANDT did a lot of work on the systems. You could approach him.

Good Luck.

Stay Safe - Have Fun - Good Luck

The above could be crap, thought provoking, useful, or . . But not personal. You decide.

[377 21]

Quote

You're in luck as I happen to have spent a good deal of time doing HAHOs from 18k and higher testing out a new oxygen mask. I'm assuming you don't have access to the same military grade O2 equipment that I do nor will you be jumping with supplementary O2?

Plan to jump with O2, good quality civilian mask with built in microphone. Will be using an almost new Kevlar wrapped aluminum bottle designed for aviation. Contents should be good for about 10-13 minutes using very rough calculations. Would like some advice on what kind of pack I should have made for it and how to attach it to my harness safely.

Setting the O2 issue aside for a moment, my other questions are what type of aircraft will you be using to get to 18K and what is the surface temperature where you plan to be jumping at right now?

Acft is King Air 200, gets us to 18K in 9-10 minutes! Calif, surface temps normally above 60 degrees F.

Once I know those things I can better tailor the answer to some of your questions.

Thanks!

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[LouDiamond 1]

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Plan to jump with O2, good quality civilian mask with built in microphone.

Without getting too deep in the physiological weeds, it would be a very good idea for you to pre-breath 100% O2 (mask not cannula; do not break the seal on the mask once you start your 30 mins time) for 30 mins prior to passing through 10k AGL. I'm not going to debate what's been done or is done currently in civilian skydiving, I am just telling you the way it should be done to mitigate the possibilities of Hypoxia and or Decompression Sickness. Since you are capable of doing what is known as a rapid ascent to altitude in the King Air, and will be under canopy at low barometric pressures for a prolonged time, it is highly recommended that you do this.

Since you are doing a HAHO with I am assuming a civilian O2 system there is the possibility it may not function correctly and or you may run out of O2 while under canopy. In which case hypoxia can be an issue due to prolonged periods of low barometric pressure. If your O2 system fails or you suspect you are becoming hypoxic while under canopy you can use what is known as Grunt breathing to increase the pressure of oxygen in your thoractic cavity.

Grunt breathing:

1. Tense all muscles and abdomen continuously.
2. Quick inhalation.
3. Expel air through pursed lips for 3 seconds.
4. Repeat cycle
5. Remember you are trying to build up a pressure within your chest.

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Calif, surface temps normally above 60 degrees F

Exposure is another concern. Rule of thumb is 2 degrees for every thousand feet for temperature. You should be able to get a forecasted temperature at your exit altitude when you get your wind data. Keep in mind you can expect at least a 20-30 min canopy ride back to the DZ if you offset far enough and you will be exposed to the air temperature plus windchill while basically sedentary for this time. A good planning tool is the Windchill/frostbite exposure chart to make sure you dress correctly. People usually blow this off or don't take it seriously because its warm on the ground but from experience I can tell you this is no joke. It can be 80-90+ degrees on the ground and with the right conditions and exposure time at altitude,be cold enough to have people land with frostbite, seen it happen.

Aircraft Airspeed at exit altitude is also something you need talk to the pilot about. The King Air is a pain in the ass to jump out at 12k and as the airspeed and altitude get higher, it doesn't get any easier. Opening at or close to 18K AGL is quite brisk no matter what you do and can be hard not only on your gear but on your body. A 5 second delay is recommended once you exit before you deploy your canopy.

I would also recommend you look into making your self some toggle stirrups. 1" tubular nylon or similar material can be used. Basically tie an overhand knot to create a stirrup for your foot and another smaller knot at the far end for a carabiner. Once under canopy, to maintain a heading, or in your case, so you have your hands free to send commo, you clip the stirrups into your toggles and steer with your feet. This also allows you to keep your hands below your heart so your arms/fingers don't feel like they are ready to fall off from lack of blood flow.


I do this type of thing for a living so if I didn't cover something in enough detail for you or was unclear just let me know and I'll be glad to go into deeper detail.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[377 21]

Thanks very much! How fortunate to be getting advice from someone who does this for a living and can speak form experience just not theory. I will be definitely be asking some more questions once I assimilate what you have already advised and figure out how to do it.

Years ago, before I had this HAHO ham radio comm idea, I spoke with a USAF flight surgeon who worked with their Pararescue Jumpers (PJs). He thought skydivers were generally ignorant and negligent about flight physiology. He said just because you can get away it most of the time doesn't mean it wont bite you really badly when you least expect it. I can see you might agree with his opinion.

I do know what you mean about warm ground temps being misleading. I got some pretty thick ice on my goggles jumping from Mullins King Air at 23k when it was over 90F on the ground. I was not prepared for that but fortunately got down to warm air fast before I got any frostbite.

I did an 18K freefall jump from the King Air 200 a week ago and it didn't seem difficult. There were a few degrees of flaps deployed on jump run, maybe that is why it didn't seem too fast. They were putting tandems out at 18K on this load after my exit.

Any clothing advice? Is thermal underwear enough or do you need down clothing?

Never thought about foot steering. Any advice for how to properly trim the length of the line below the clip? Suspended harness?

Hadn't considered prebreathing O2 for 30 min. I don't think that will be too hard to arrange. I'll need to rig some quick disconnect couplers on the ground and flight O2 cylinders.

How low a HAHO wold eliminate the need for any O2 gear/breathing? I want a long time under canopy to get enough time for commo, but maybe 14K is a better idea? Do you still need all the O2 precautions?

Thanks again.
Mark

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[firstime 0]

Glad I read this thread (normally don't) I think I will stick to my normal 13 5's

[LouDiamond 1]

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I spoke with a USAF flight surgeon who worked with their Pararescue Jumpers (PJs). He thought skydivers were generally ignorant and negligent about flight physiology.

Generally speaking, I would have to agree. Partly due to lack of training, equipment and having "gotten away" with doing it the wrong way for so long in the civilian skydiving community. There are plenty examples of people getting hypoxic on jumps(there is actually a video floating around of a severely hypoxic jumper in the aircraft thats an eye opener) but the general attitude seems to be "that won't happen to me" or "I don't jump above 12.5k so I don't have to worry". The bigger concern(IMO) is with the the big ways going higher and higher using only nasal cannulas and making multiple rapid ascents in one day. It's only a matter of time before someone has a decompression sickness related injury IMO. Everyones physiology is slightly different from the guy next to them so symptoms and reactions can differ from person to person which is why there is a general list of symptoms. The only way to figure out what your symptoms are is to do a chamber ride and experience it first hand.

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Any clothing advice? Is thermal underwear enough or do you need down clothing?

That really depends on what the temp at altitude is. Generally speaking, your normal cold weather gear and a good set of gloves should suffice. If it's forecasted to be in the negative numbers at altitude I suggest serious out door gear. Contact with items,especially metal ones needs to be considered as it is easy to get frostbite quickly when exposing skin to extreme temps and or when its in contact with metal objects. At 18k, unless it's forecasted to be in the low to negative numbers, it shouldn't be a concern.

Quote

Never thought about foot steering. Any advice for how to properly trim the length of the line below the clip? Suspended harness?

That is jumper specific. Ideally, you want the stirrups to be long enough that it keeps your canopy at 50% brakes when your feet are in the stirrups yet allows you to straighten your leg to make directional inputs as needed. It's no different than flying 50% brakes with your hands, only now you need to be able to do it with your feet.

Quote

How low a HAHO wold eliminate the need for any O2 gear/breathing? I want a long time under canopy to get enough time for commo, but maybe 14K is a better idea? Do you still need all the O2 precautions?

In the military, anything below 18k feet AGL does not require the use of supplementary O2 as long as you do not exceed 30 mins above 10k AGL. 18K AGL is the magic number in the military for the need to begin using O2. So in your case, a jump from say 17,999 AGL wouldn't require O2 but since it a HAHO it wouldn't be a bad idea to have supplementary O2 while under canopy. That should be plenty of time to make commo if you plan on simply dropping a precut longwire antenna once under canopy and transmitting.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[377 21]

Your patient seasoned advice to HAHO newbies is very much appreciated.

Sounds like an 18K hop and pop with supplemental O2 is pretty safe. Just for bragging rights in the ham radio community 20K would be better, but based on what I am learning from you and others I doubt if I am going higher than 20 and may just do 18.

I dont want to impose on you but I hope you will be open to further questions as they arise. Right now I am pondering regulators, but I do not know enough to ask intelligent questions yet.

Antennas will likley be coax dipoles which will basically be a piece of coax hanging down and cut so that it acts as a resonant center fed dipole antenna on the band of interest, probably 20 meters (14 MHz).

Thanks again for the help!

Blues,
Mark

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[LouDiamond 1]

Quote

I dont want to impose on you but I hope you will be open to further questions as they arise.

Not at all. By all means ask if you have a question.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[Erroll 75]

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..In the military, anything below 18k feet AGL does not require the use of supplementary O2 ...

AGL? Is that right?

[LouDiamond 1]

Quote

Quote

..In the military, anything below 18k feet AGL does not require the use of supplementary O2 ...

AGL? Is that right?

Good catch, correction, it should be MSL.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[propofol65 0]

Are you looking at using an HF rig or just carrying a 2m/220 HT?

Blue Skies!
Bob
KD8FUZ (ex-N8EYN & KA4GTH)

[377 21]

HF QRP rig. Icom 703. Probably 20 meters.

73
Mark

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[jumpwally 0]

Out of curiousity, what exactly are you trying to do ?

smile, be nice, enjoy life
FB # - 1083

[377 21]

Quote

Out of curiousity, what exactly are you trying to do ?

Just operate ham radio gear from under canopy starting at 18K. If conditions are good we might be able to make HF SSB radio contacts thousands of miles away. Of course it isn't a big deal in skydiving, but it is getting some attention in ham radio, a far more docile hobby.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.

[theonlyski 3]

Quote

Quote

Out of curiousity, what exactly are you trying to do ?

Just operate ham radio gear from under canopy starting at 18K. If conditions are good we might be able to make HF SSB radio contacts thousands of miles away. Of course it isn't a big deal in skydiving, but it is getting some attention in ham radio, a far more docile hobby.

377

You know, HF SSB has been done before, on the ground, and around the globe... I remember something about a 1/4 watt club.

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

[377 21]

Yeah, HF SSB is old stuff. The USAF stated using it in the late 50s for long distance comms with strategic bombers.

from Wikipedia:
Genral Curtis LeMay was an active amateur radio operator. He was famous for being on the air on amateur bands while flying on board SAC bombers. LeMay became aware that the new Single Side Band (SSB) technology offered a big advantage over Amplitude Modulation (AM) for SAC aircraft operating long distances from their bases. In conjunction with Art Collins (W0CXX) of Collins Radio, he established SSB as the radio standard for SAC bombers in 1957.

Doing it parachute mobile is kinda novel though.

377

2018 marks half a century as a skydiver. Trained by the late Perry Stevens D-51 in 1968.