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  1. #1
    Join Date
    30th May 2017
    Location
    vermont
    Posts
    55

    Large parachute preparation

    So i'm finishing up my L3 project and as i'm ground testing the ejection charges i realized folding and packing this parachute maybe more difficult in the field. The parachute i'm using is a skyangle cert-3 XL, are large chutes like this ok to pack the night before flying? Somtimes nasty wind makes my smaller chutes hard to fold, i can only imagine with the cert-3.

    Eric M
    NAR#85115 L2

  2. #2
    Join Date
    18th January 2009
    Location
    Savannnah, Ga
    Posts
    7,715
    Yes, I have packed my Cert 3 XXL weeks or even months before flight.
    I set main for 900 and backup 700 to give plenty of time for larger chute to inflate.

    Jim Hendricksen
    L-3 Tripoli 9693
    [ICBM, Orangeburg,SC R.I.P.] - QCRS ,Princeton ILL - MDRA , Price Maryland - Woosh, Bong Wisconsin- ROCC, Charlotte NC , ICBM Camden SC
    "Made" member of Chicago & Carolina Rocket Mafia
    Rocketry...........an exact science.......but not exactly !!!

  3. #3
    Join Date
    7th July 2013
    Location
    Toronto
    Posts
    3,310
    I recall reading a study,I believe conducted by the US military on this subject possibly from the 40s or 50s, likely have that wrong. The gist of it was, did packing and storing chutes result in lower reliability or higher failure rate, and essentially the answer was no. I can't recall the number chutes they looked at or time frames but I recall that it was compelling. If I find the study, or if someone else knows about this please post it.

    Having said that, long tern chute packing is one of those things that I can never quite get comfortable with so I do prefer to pack it the night before in the peace of the hotel room.
    Michael Pitfield
    TRA 14579 L2
    NAPAS BoD
    URRG
    MARS
    CRC

  4. #4
    Join Date
    26th November 2009
    Posts
    4,912
    Quote Originally Posted by mpitfield View Post
    I recall reading a study,I believe conducted by the US military on this subject possibly from the 40s or 50s, likely have that wrong. The gist of it was, did packing and storing chutes result in lower reliability or higher failure rate, and essentially the answer was no. I can't recall the number chutes they looked at or time frames but I recall that it was compelling. If I find the study, or if someone else knows about this please post it.

    Having said that, long tern chute packing is one of those things that I can never quite get comfortable with so I do prefer to pack it the night before in the peace of the hotel room.
    Night before isn't so bad. If any chute is packed very tightly in a very small space, one runs the risk of creases setting up if allowed to sit for a long time.
    Ya get the risk of a "para wad" deployment. Opening up high might give 'er more time to open but with small chutes, they sometimes don't clear the
    chute protector and a fast descent is noted. Kurt

  5. #5
    Join Date
    27th March 2011
    Location
    Texas
    Posts
    590
    We leave pressure packed personnel chutes in in their containers on the seat for up to 4 years. It should no be a problem for a few days.
    Mike J

    Parachute Rigger


    There is no such thing as a "parasheet".

  6. #6
    Join Date
    26th November 2009
    Posts
    4,912
    Quote Originally Posted by jazzviper1 View Post
    We leave pressure packed personnel chutes in in their containers on the seat for up to 4 years. It should no be a problem for a few days.
    I suspect there might be a difference in parachute size, material and technique that portends long-term storage ability in a deployable state. I think the smaller parachutes used in rocketry along with stiff parachute protectors increases the risk of a para-wad. Kurt

  7. #7
    Join Date
    18th January 2009
    Location
    Savannnah, Ga
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    7,715
    Quote Originally Posted by ksaves2 View Post
    I suspect there might be a difference in parachute size, material and technique that portends long-term storage ability in a deployable state. I think the smaller parachutes used in rocketry along with stiff parachute protectors increases the risk of a para-wad. Kurt
    Small plastic Estes type chutes, I agree. However I have 12in. up to 144in. nylon chutes of all types that have been folded/packed in nomex for 1-2 yrs. that function fine every time.

    After a launch , I clean airframes of BP residue, fold/pack chutes for next time & install in my rockets. They stay there till next time rocket gets launched.

    I believe this success is due to my technique, style of fold/pack, years of experience & attention to details.
    I can see where this is not for everyone, especially newer flier's with minimum experience.

    Truly another testament of: one size does not fit all, when it comes to rockets.
    Jim Hendricksen
    L-3 Tripoli 9693
    [ICBM, Orangeburg,SC R.I.P.] - QCRS ,Princeton ILL - MDRA , Price Maryland - Woosh, Bong Wisconsin- ROCC, Charlotte NC , ICBM Camden SC
    "Made" member of Chicago & Carolina Rocket Mafia
    Rocketry...........an exact science.......but not exactly !!!

  8. #8
    Join Date
    19th January 2009
    Location
    Stafford VA
    Posts
    7,043
    I agree with Jim, one size does not fit all.

    I haven't left my chutes packed for extended periods, but I have flown rockets that had been prepped for weeks with the chutes packed.

    With that said, I do believe size has a lot to do with how well that works. If you leave a plastic Estes chute in a rocket a long time, it probably won't open. First because the plastic is stiff and sets, and second because the Estes type rockets are usually so light they never get enough speed while dropping to force the chute open.
    Handeman

    TRA #09903 L3 3/29/2015

    "If you don't use your head, you have to use your feet!" my Dad

    Tripoli Central Virginia #25 - BattlePark.org

  9. #9
    Join Date
    26th November 2009
    Posts
    4,912
    Agree on plastic but some thick nomex protectors can have issues without careful harness placement in the cold. Again, I've noted more of a problem with smaller chutes than larger chutes. A loose pack situation
    is better then a tight pack and a long slender deployment bag with a tight pack, with a too small of a pilot chute can mean no deployment. I got a video of that buried on the computer. There is a reason that Ky's Rockman deployment bags are designed the way they are and are not long and narrow. Also one can't go wrong if they use a particular makers D-bag with one of their chutes. If one experiences a few para-wads they'll learn quickly. Kurt

  10. #10
    Join Date
    30th May 2017
    Location
    vermont
    Posts
    55
    Thanks everyone very useful info, I'll have to prepare it ahead of time. After doing all the ground test ejection charges i struggled repacking it in the yard. I'm wondering if the 5" diameter airframe and skyangle chute is making it pack long, i'm hoping this doesn't cause deployment problems.
    Eric M
    NAR#85115 L2

  11. #11
    Join Date
    10th July 2007
    Location
    Melbourne, Australia
    Posts
    1,267
    I had a Cert 3 XL packed for about five or six months. Worked perfectly.

    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

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