My newest addition

[BrianQ]

Jumping out of a plane sounds like it would be fun. But what if the chute doesn't open? Do you pack your own? Halo jump with O2 sounds crazy, and pretty cold to me. What is the outside temp during those?

I took the easier route and scuba. Still have the O2, but a much slower and shorter fall, warmer too.

If the parachute doesn’t open, or open correctly, you cut it away and deploy the reserve. The main parachute is packed by the owner; the reserve is packed by an FAA certificated rigger. Outside temp depends on altitude, time of year, location, etc. Currently the temp here in eastern NC at 24k feet MSL is -19C. I've seen it snow in August inside the aircraft when the tail gate is opened at 24k feet. A 90+ degree temperature difference between exit and landing isn't outside the norm.

[Bill Hollinger]

Wow Brian. That is so cool. I would imagine the temperature extreams would play heck with equipment. Thta equipment would have to be to the gnat's rear end for sure. Maybe a dumb question but I have seen this "MSL" before. What does that stand for?

[JimF4M1s (Deceased)]

If the parachute doesn’t open, or open correctly, you cut it away and deploy the reserve. The main parachute is packed by the owner; the reserve is packed by an FAA certificated rigger. Outside temp depends on altitude, time of year, location, etc. Currently the temp here in eastern NC at 24k feet MSL is -19C. I've seen it snow in August inside the aircraft when the tail gate is opened at 24k feet. A 90+ degree temperature difference between exit and landing isn't outside the norm.

Ok Brian, I'm curious now. I knew there was a reserve, is the reserve the same size as the main? I have seen the new rescue knives. Anyone still using MC-1 knives?

I am guessing you use some kind of anti fog for your face shield at -19C? What are the face shields made of, and does going from -19C (-2.2F) to 88F in such a short time cause thermal cracking?

How long is the jump, time wise?

I think Halo jumpers are a special breed, a lot can go wrong.

Bill, MSL is Mean Sea Level.

[Bill Hollinger]

Thanks Jim, okay, what is a HALO jumper???

[Mike Haas]

Thanks Jim, okay, what is a HALO jumper???

The individual that survives impact after both the "Main" and the "Reserve' chutes fail to open!!

[BrianQ]

On the military rigs the reserve is generally the same size as the main, in fact most of the time the canopies are the same and can be used as either main or reserve. With civilian skydiving rigs the reserve is usually smaller than the main but not in all cases. With today’s ultra small main canopies the reserve is often a good bit larger.

Some guys jump with the face shield that comes with the Gentex helmet but most just use standard goggles, clear for night and O2 and shaded for day time. Most any type of goggles will fog but they clear almost immediately on exit. Fogging is more of a problem on low altitude jumps when it’s hot out. There is no noticeable effect on equipment due to the temp differences because the equipment never reaches the ambient outside air temperature at altitude.

Time wise depends on exit altitude and opening altitude. Approximate time is six second for every thousand feet. An exit at 25,000 feet with an opening at 3500 feet gives just over two minutes in freefall. Body mass, surface area and position all affect fall rate. By changing your body position you can slow down or you can speed up but you’re always going down. Once under canopy your suspended time is dependent on opening altitude, suspended weight, number of turns, winds aloft, and to a lesser degree relative air density.

HALO is an acronym for High Altitude Low Opening, which means you exit freefall to a lower altitude and then open the parachute. HAHO is High Altitude High Opening. The difference being the canopy is opened very soon after exiting with only a short freefall. With a HAHO jump you can drive the canopy for many miles prior to landing. When exiting a high performance aircraft, C-130, C-5, C-17 etc., you slow down after exit. The aircraft is flying faster across the ground than you will be falling towards it. That’s is why on a HAHO you generally open 1000 feet after exit to give yourself time to slow down. That and it gives the guys that tumble on exit time to get stable!

[Bill Hollinger]

Very interesting information Brian. Thank you for the schooling on parachuting. I've watched a number of guys jump from C47s in films and thought wow. Especially with that old gear. I'll bet that has come a great distance since then. I've never jumped out of a plane but I sure would if I had the chance.....well okay maybe not at my age now.

BTW, sorry Frankie for highjacking your thread.

[JimF4M1s (Deceased)]

Brian,

Both are being deployed from the plane at high altitude. HAHO opening 20,000 ft sooner and covering more distance, is that for a more covert drop?

You didn't mention what is used now to cut away tangled chutes?

[BrianQ]

A HALO or HAHO can be from any altitude, the min exit altitude is 4500 feet. A HAHO is usually for infil into a denied area that cannot be over flown.

Chutes rarely tangle and the main is cut away by pulling the cutaway handle which releases the main. There is no standard issue knife for cutting lines.

Most civilian jumpers and some military use a hook knife which is nothing more than a single edged razor blade in a plastic or metal housing designed so only a small portion of the blade is exposed inside a deep channel.

[frankderrico]

Bill, no apology needed. This became an interesting thread on advanced military parachuting. I've been enjoying it.

Brian, thank you for sharing your knowlege.....Frank