quade 4 #1 January 6, 2003 Flight test jump #1 - 030105 09:42am Spectre 190 loaded at 1.2:1 Full altitude camera jump followed by specific maneuvers. Data recorder = Kestral 4000 2 second interval Flight test to determine if Kestral works properly as chart recorder. Secondary goal of acquiring baseline rates of decent. From 9:42:56 to 9:43:16 flew in straight line with brakes in deployment setting. Average decent rate = -984 fpm From 9:43:44 to 9:44:06 flew in straight line at full flight. Average decent rate = -1385 fpmquade - The World's Most Boring Skydiver 030105-Jump1.xls Quote Share this post Link to post Share on other sites
Hooknswoop 19 #2 January 6, 2003 Very cool. Keep us posted on future test jumps. Did it also give you airspeed? Hook Quote Share this post Link to post Share on other sites
quade 4 #3 January 6, 2003 I'm going to get airspeed on future jumps, but I need to figure out how to go about holding the damn thing while flying. For deployment brakes and full flight it shouldn't be too much of an issue, but I also want to try to get a range of measurements from full flight to stall. I don't think I can hold it in my hand for a full stall and get accurate readings, but I might figure that out at some point. I'm -thinking- about a helmet mount but haven't decided on how best to go about that yet.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
PhreeZone 20 #4 January 6, 2003 Have you looked at a foot mount bracket yet? It would keep it out of the way of any snag hazards and the slider could'nt disrupt the airflow like it could in a top helmet config.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
quade 4 #5 January 6, 2003 Well, the real issue, as I see it, is keeping the thing aligned with the relative wind. I think that's going to be tough with a footmount.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
SkydiveMonkey 0 #6 January 6, 2003 What about chest strap?____________________ Say no to subliminal messages Quote Share this post Link to post Share on other sites
quade 4 #7 January 6, 2003 I don't think the chest strap is going to work either. Ideally, you'd want good unobstructed airflow in front and behind the unit. On a chest strap you'd block the airflow exit and it just wouldn't be accurate. Not to mention that my body will create a stagnation point -- kinda like a bow wave on a boat.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
NtheSeaOrSky 0 #8 January 7, 2003 dangle it??Life is not fair and there are no guarantees... Quote Share this post Link to post Share on other sites
quade 4 #9 January 7, 2003 Actually, that idea isn't entirely without merit! All I'd have to do is attach some sort of weathervane to keep it pointed into the wind.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
SkydiveMonkey 0 #10 January 7, 2003 And maybe a weight underneaty to keep it vertical (or more vertical)____________________ Say no to subliminal messages Quote Share this post Link to post Share on other sites
PhreeZone 20 #11 January 7, 2003 Shoe mount it, just point your toe into the wind...Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
NtheSeaOrSky 0 #12 January 7, 2003 dangle it and then reel it back up before landing lol amazing how tough we make things when they can really be simple Life is not fair and there are no guarantees... Quote Share this post Link to post Share on other sites
ernokaikkonen 0 #13 January 7, 2003 >All I'd have to do is attach some sort of weathervane >to keep it pointed into the wind. You could also dangle it from two points right and left, that could keep it on heading reasonably accurately. Quote Share this post Link to post Share on other sites
nacmacfeegle 0 #14 January 7, 2003 "All I'd have to do is attach some sort of weathervane to keep it pointed into the wind." Okay, you are going to giggle at the imagery, but I've seen a setup to measure true airspeed which was mounted on top of a gath........ Back in 98 I met a french guy who was experimenting with wingsuits (not Patrick) He had a small anemometer mounted on a gimbal with a weather vane / dart attached as a tail to keep the thing into wind. On one of the propellers, there was a small magnet(?) on the gimbal frame was a sensor. This was hooked up to a Mini disc type recorder, the sensor/magnet combo made a beep for every revoltion of the 'propeller', the higher the tone heard the faster the air speed....It sounded relatively straight forward to calibrate, as there is all sorts of software available to analyse the 'sound of the speed'. As I said earlier, the whole contraption was mounted on top of the helmet, and it would give a permanent record. I would guess it would be relatively simple to mod an existing anemometer for such a purpose. But you may not have to mount it on your head... -------------------- He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson Quote Share this post Link to post Share on other sites
quade 4 #15 January 7, 2003 Quote amazing how tough we make things when they can really be simple Well, in fact, the entire thing -is- simple if all I wanted to do was to go straight forward. You're right. Just lower it on a string with a weather vane to keep it pointed. However . . . This doesn't really work too well if I decide I want to get some data while spiraling down. The farther out on a line the device is, the farther the distance it will cover in a spiral and the readings will become meaningless. Kind of like asking the airspeed of a helicopter in a hover. The fuselage might be going zero, but the rotor tips are going like a bat outta hell.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
billvon 3,009 #16 January 7, 2003 >This doesn't really work too well if I decide I want to get some data while spiraling down. If that worries you, even a body mount is useless. The airfoil will see a different airspeed than your body, and your body's airspeed just isn't that relevant to how the canopy flies. Quote Share this post Link to post Share on other sites
Hooknswoop 19 #17 January 7, 2003 What about a waist band w/ a short pole that goes out to the left or right from your waist? Like a camera belly-mount system worn with the camera on your side. Hook Quote Share this post Link to post Share on other sites
quade 4 #18 January 7, 2003 Quote If that worries you, even a body mount is useless. Yeah, I know! This is all pretty simple -- right up until the time it isn't. The spiral stuff I'll probably just have to infer from the decent rates. That's really what is going to be interesting anyway -- what would the impact speed be if taken all the way to the ground. What kind of decent rate would you be looking at if you had a toggle that hung up after deployment -- stuff like that. For those I wouldn't really need airspeed at all -- I can infer that from the decent rate.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
dreamsville 0 #19 January 7, 2003 John LeBlanc recommends deep brakes versus brakes stowed for slowest rate of descent. Have you tested this? HarryI don't drink during the day, so I don't know what it is about this airline. I keep falling out the door of the plane. Harry, FB #4143 Quote Share this post Link to post Share on other sites
quade 4 #20 January 7, 2003 Quote John LeBlanc recommends deep brakes versus brakes stowed for slowest rate of descent. Have you tested this? You'd have to define "deep brakes". It would also depend on so many personal factors that any vague term such as "3/4 brakes" is probably equally meaningless. Personal factors might include, body type, arm length, riser length, lower control line settings. For me, "deep brakes" is a point just above the stall point and for my canopy this would be decending pretty fast. At least that's what my gut tells me. It's also what a normal polar curve on a glider would show. I will say that if I want to have minimum sink, that I'll usually pull my toggles down to the laterals of my harness and hook my thumbs under them to make it easier to hold them there over the course of time. My gut tells me this is "just about right" but I don't yet have any data to back that up. This would be a simple rate of decent issue and wouldn't require forward airspeed data, so this -should- be something I can figure out just by carrying the unit on a couple of jumps.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
dreamsville 0 #21 January 8, 2003 Deep brakes for me is just above the stall point, as you say. I am 165lbs plus a Stiletto 135, J1, and PD143 out the door (loading is about 1.4). It works on long spots for me, if I allowed it to happen in the first place (don't blame the pilot automatically). I just figured that if someone was measuring it might be interesting to know. As a practical matter, if I'm down to this level of tolerance, I have probably misjudged the spot anyway. Thanks, HarryI don't drink during the day, so I don't know what it is about this airline. I keep falling out the door of the plane. Harry, FB #4143 Quote Share this post Link to post Share on other sites
quade 4 #22 January 8, 2003 QuoteDeep brakes for me is just above the stall point, as you say . . . It works on long spots for me, if I allowed it to happen in the first place (don't blame the pilot automatically).Actually, I can't imagine that flying in deep brakes, just above the stall point, would be good under any circumstances.There are two really basic airspeeds you'd want to try to be able to get to on your canopy; Best Glide Speed and Minimum Sink Speed.Best Glide Speed will give you the farthest distance under no-wind conditions.Minimum Sink Speed will give you the most time aloft.These are two distictly -different- speeds and both are faster than just above the stall speed of the wing.There is yet another speed that we'd all like to know and one that I'm trying to develop for my canopy with me under it. That speed is called "Speed to Fly".Speed to Fly is variable depending upon a couple of factors; winds and thermals. In order to develop this I'll have to make what's known as a polar curve for my canopy. After that, it's a fairly simple matter of drawing tangents. I'll explain the entire process later when I have some hard data.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
