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Thread: Flight Testing - Airframe vs Personal Parachute

  1. #21

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    I would have both personal and airframe chute for testing. Reason - while spin testing a local design here in South Africa the plane got into an un-recoverable spin. The airframe chute was deployed but failed to be come out of the aircraft. The two test pilots then had to exit the aircraft and were saved by their personal chutes. Had they relied on the airframe chute they would not have survived. Do you know your airframe chute will work properly? Theirs did not.
    Neil

  2. #22

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    I find this thread to be of particular interest, since I've been one of the engineers with BRS for 25 years (as of December). I have just a few quick comments regarding some of the posts in no particular order.
    1. One of the biggest mis-representations regarding deployment of a whole aircraft recovery device is the idea that "you're giving up control" to the parachute. Where its true that you don't have much directional control (thats another discussion), at the time you actually need a ballistic parachute, you're NOT in control of the situation anyways - events are going to occur no matter what input you may apply. The parachute, which is merely another aerodynamic device on the aircraft similiar to ailerons, flaps etc., is activated by the pilot to regain control of the situation.

    2. Parachute deployments are always preceeded by unforeseen events. NO ONE would willingly fly ANYTHING if they believed that something horrible WILL occur on that flight. Even in the very early UL days when people were flying things made from hardware store crap, less than 25% of deployments were due to something associated with aircraft structure. Its the unforeseen things that will get you.

    3. There is absolutely no question regarding altitude required for safe deployment when comparing a pilots safety rig to a ballistic system. We just recently had a Cessna 182 save from less than 300' AGL. That is NOT a possibility with a pilots rig at all. Even an experienced sky-diver would need to be out and clear of the aircraft by 1000' agl. Keep in mind, most emergency conditions that have occurred which resulted in a ballistic parachute deployment occurred below pattern altitude.

  3. #23
    Mike Switzer's Avatar
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    Quote Originally Posted by Jeff Peltier View Post
    most emergency conditions that have occurred which resulted in a ballistic parachute deployment occurred below pattern altitude.
    Interesting - I was not aware of that

  4. #24
    Here's a thought. When I was rodeoing in my Bonanza I used it like one would a car. Put over hundred hours a month on it. I figured I could put it down in a creek bed in the mountains and survive. Only thing I worried about was losing a tail or wing or fire at altitude and not being able to get down to ground before it burned up. So, I guess if I had to chose between the two, I'd take the personal chute. Could get away from burning plane (maybe if lucky) and could bail out if lost part of the plane (maybe, if luckey). Best deal would be to have both types. If plane on fire, bail out. If lose a wing or tail, use the BRS. Otherwise, don't fly at night or in the clouds, and don't jump out of a flying airplane.

  5. #25
    highflyer's Avatar
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    An airframe parachute is a design decision and typically requires airframe modification for it to work properly.

    A personal parachute for the test pilot is not a bad idea. Particularly for flutter testing, and spin testing. I do not own my own personal parachute. What I have done is contact a local skydiving group and see if they have an older chute that they will rent out. The fixed me up with a nice thin pack chute and only charged my $25 for a days rental for the relevant flight tests. I have had more than one engine failure in my career and have never needed a chute for an engine failure. If fact, I never even damaged an airplane because of an engine failure. Your mileage may vary.

    I know there is a skydiver group in Vandalia, Illinois. There may be others closer to your location.

  6. #26

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    Aug 2011
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    What About a Spin Chute?

    No one has mentioned a spin chute, much smaller and goes out the rear to get the pointy end going forward again. Most designs can be later released when things are back under control. When using a whole aircraft chute or a personal chute, the last thing that should be on your mind is the airplane (save that precious cargo). One can't go through ALL the scenarios, but try. For example, will the whole airplane chute work if the airplane is spinning (and/or tumbling, inverted, etc). In addition can you personally get out of the airplane if you had to? And practice that over and over and over.

    I talked to a guy at OSH one year about getting out of his Berkuit (sp) - long EZ type airplane. He had a small hole through the panel area that his legs stuck through (no walled tunnel for his legs). If the airplane were in any other attitude than straight and level (not normally the condition that one is leaving the airplane under), his legs would have been stuck (flailing around) behind the panel.

    As mentioned earlier, a canard should be designed so the canard stalls first ... always. All single engine TCd airplanes are fully spin tested (regs ... with some exemptions like the Cirrus designs). No multi-engine TCd airplanes are spin tested (no regs). And, before I get flamed, yes military fighter jets are all spin tested ... their flight envelope is a little different.

    Great discussion.

  7. #27

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    I work with a gentleman who was the former chief designer at Piper. He tells me that spin chutes were mostly a failure in use. I understand that a number of anti-spin devices (small parachutes, rocket motors, etc) were tried and none were found to be reliable. Did not go into the specifics with him. The bottom line was that the Piper flight test staff wears parachutes and plans to exit the airplane if needed. For what it is worth, large scale RC models are used to do a lot of the pre-first flight evaluation of the potential spin characteristics of new designs. If you are really concerned about how your original design might perform, work the math to appropriately scale it down and build a flying model. I understand that Burt Rutan started that way.

    Oh, and yes light twins are in fact spin tested. I have had some interesting and educational discussions about spin testing twins with my co-worker. But I do not suggest that you explore that topic in your own airplane.

    Best of luck,

    Wes
    N78PS
    Last edited by WLIU; 11-16-2011 at 07:18 AM.

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