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Posts posted by spinglebout

  1. Haha! Yeah.. I'm doing my final semester undergrad. At moments like this, I truly feel like I have dug my own grave by choosing ram-air parachute analysis.
    But no matter, your thoughts actually make me feel a little less crappy.B|
    As of now, I'm going to go with whatever data I can acquire. Also, I'm going to pay a visit to my local DZ here in DUbai. Hopefully I will get more insight into the matter and come back with a better set of questions in the forum

  2. thanks for the reply RiggerLee!

    I am doing a research project on canopies and I'm trying to do a comparative analysis between a canopy designed for a student and a canopy designed for an expert... in terms of performance. Low performance for the student and high performance for the expert. (correct me if my statement is wrong)

    So using several hypothetical and quantitative input variables such as different exit weights(150lb and 200lb(, different inflation times(2 secs and 3 secs), different canopy opening altitudes (2000ft, 3000ft)etc. for both low performance and high performance canopies. Ill also be talking about the effect of varying density altitudes, canopy materials etc. to support the analysis

    Now my difficulty lies in identifying a fixed set of performance factors that can 'influence' the way the canopy behaves for both low performance and high performance. This way I have a list of factors to work on analyzing in terms of different input variables.

    (still in the process of figuring everything out.. pardon me if i sound vague in any way)

  3. dragon2

    For a Performance Design - Velocity (Expert level)
    - At what altitude would an average 150lb person deploy his parachute? (Mean sea level)

    An average 150lb jumper wouldn't be jumping a velocity ;)
    But generally, anyone jumping a high-performance canopy like that opens a little bit higher than 'mandatory', because generally these type of canopies open relatively slow, you need more altitude to deal with opening issues, and oftentimes these jumpers have specialized gear that takes a bit of time to stow away (RDS). I don't think many of these jumpers open below 3000ft (above the ground, not MSL unless you're in The Netherlands... ;))

    - What would the inflation time be?

    Skydivers don't usually use 'time' as a reference, but altitude. A velocity could take up to ~1000ft to open I believe, but presumably someone who jumps them can provide a more accurate answer.

    - At what airspeed would he be travelling (MSL)?

    Before or after opening? Before opening if you did a 10sec freefall or more, generally you're travelling at 120mph-ish. After opening, it depends on the wingloading (jumper + equipment weight in lbs/sqft of the canopy) and how you're flying. if you're hanging in breaks you do down relatively slow, if you're doing a high-performance turn on a canopy like a velo, you can beat 13m/s...

    If possible could I have the above values for a PD-Navigator (Student level) and a PD-Stiletto as well?

    A student would open higher, starting at 5000ft and moving down slowly, and a navigator, like most student canopies, opens fairly quick.

    A stiletto is for a jumper with 300-500 jumps or more, presumably this jumper is free to open at 2000-2500ft. A stiletto generally opens fairly slow, so in between the nav and the velo.

    Thanks so much for the information! It really helped!
    And yeah I was looking for the airspeed at the moment of canopy extraction. Basically, the pre-inflation fall rate! :)

  4. Well.. I was referring to MSL because the inflation-force calculation diagnostic tool that I am using requires altitude in MSL
    I am still learning about a lot of new terms and concepts and I hoping once I'm more well versed on this subject (which should be very soon) I would be able to ask more informed questions :)

  5. Hi everybody!

    Could someone please help me categorize canopies from Performance Designs as well as Incarus Canopies in terms of skill level?

    For example,
    Could I have one example of a Student level canopy each from PD and Icarus. Same for a Tandem, High performance canopy etc?

    Please feel free to provide your own suggestions for categories. If it's a subjective matter, your personal opinion on the ideal canopy for the particular skill level is fine too

    I'm doing this for a project as a basic comparative analysis. :)

  6. Hi everybody!
    I'm new to Dropzone.. and I'm loving it so far. I'm a student of Aeronautical Engineering and I'm currently doing my final Project in Sport Parachuting. For kicks, I'll be doing my Tandem jump sometime next month(excited!):ph34r:

    I need a some data for an analysis I'm conducting and I'd really appreciate any help from experienced skydivers out here.
    Here goes:

    For a Performance Design - Velocity (Expert level)
    - At what altitude would an average 150lb person deploy his parachute? (Mean sea level)
    - What would the inflation time be?
    - At what airspeed would he be travelling (MSL)?

    If possible could I have the above values for a PD-Navigator (Student level) and a PD-Stiletto as well?

    Thanks! :)