PhreeZone 15 #1 May 25, 2010 I was talking to someone and they were telling me about an event over the last few days where on a dropzone in California they experienced 2 AAD's in Student mode that fired on the plane decent since they were unable to get to altitude with their students. I guess there were 2 makes of AAD's on the airplane and only the one type activated and the other did not. I don't know what mode the other AAD was in so its possibly not an apples to apples comparison of AAD's. The question that I have for everyone is if you are riding the plane down do you turn the AAD's off on your students or other jumpers? I know this is not typical practice since most jumpers have their AAD's in Expert mode which needs a faster decent then the student mode to trigger but I am not sure about Student mode since that tends to be used less frequently.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
riggerrob 558 #2 May 25, 2010 Back in 1979, I had an FXC 8000 fire in my lap as we descended in a jump plane. The scenario was that we tried to sneak a jump through a "sucker hole" in a layer of stratus clouds. We climbed above the clouds and flew around for 20 minutes, but never found a hole near the DZ, so the pilot dived through another hole and the FXC pulled my reserve ripcord. The FXC probably fired within published limits. The morale of the story is that pilots can save everyone a lot of grief if they fly politely in the traffic pattern. Quote Share this post Link to post Share on other sites
riggerpaul 1 #3 May 25, 2010 QuoteI was talking to someone and they were telling me about an event over the last few days where on a dropzone in California they experienced 2 AAD's in Student mode that fired on the plane decent since they were unable to get to altitude with their students. I guess there were 2 makes of AAD's on the airplane and only the one type activated and the other did not. I don't know what mode the other AAD was in so its possibly not an apples to apples comparison of AAD's. The question that I have for everyone is if you are riding the plane down do you turn the AAD's off on your students or other jumpers? I know this is not typical practice since most jumpers have their AAD's in Expert mode which needs a faster decent then the student mode to trigger but I am not sure about Student mode since that tends to be used less frequently. I just checked the big 3 AAD manuals. All recommend turning off student or novice devices if possible if you must descend with the aircraft. Different manufacturers have different amounts of detail in the manuals, but all eventually recommend turning the units off when students are descending with the aircraft. Quote Share this post Link to post Share on other sites
regulator 0 #4 May 25, 2010 How can you turn off a cypres after it's already been activated? Quote Share this post Link to post Share on other sites
piisfish 135 #5 May 25, 2010 as written in the manual, same as turning it on, press the button 4 times, the only difference is the 1st time you press it should be a "sharp" pressscissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
USPA 0 #6 May 25, 2010 All manufactorers recommend turning off student AAD. That being said, we only turn of FXC. Of the electronic AADs, the cypres is most easily scared (13 m/s at 1000 feet) at aprox 2500 feet/minute Although extreme such a measurement is possible during a "normal" descent at 1000 feet. Our pilots have strict instrucions to keep descent speed way below 1000 feet/minute from 3000 feet and lower, if we do a descent with students aboard...The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
GLIDEANGLE 1 #7 May 25, 2010 Yes, we turn off student AADs if the student rides the plane down. First time this happened to me with an unlicensed coaching client, I struggled w/ the AAD switch and never got it off. I told the pilot and while he wasn't delighted, he altered his descent and all was well. After that I practiced turning the student AADs off a few times on the ground. Not a problem for me any longer.The choices we make have consequences, for us & for others! Quote Share this post Link to post Share on other sites
davelepka 4 #8 May 25, 2010 QuoteThe question that I have for everyone is if you are riding the plane down do you turn the AAD's off on your students or other jumpers? My question would be why not? It only takes ten seconds to turn it off, and ten to turn back on again when you get to the ground. What's the downside? In reality, if you ride the plane down due to weather your jumping day might be over anyway, so you can disregard the ten seconds it takes to turn it back on. I would rather take the time to turn off any AAD then risk an unwanted firing in the plane. That would take alot longer than ten seconds to correct. Quote Share this post Link to post Share on other sites
sundevil777 94 #9 May 25, 2010 I think it would be very tough to turn them off if you have 3 students plus a jumpmaster in a C182. All the moving around might also result in the jumpmaster moving his weight to the back when the plane is full and flying rather slow...a bad combination. I can understand wanting to avoid an activation and allowing the pilot to fly without restriction, but don't think it is practical in a full C182.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
PhreeZone 15 #10 May 25, 2010 How about tandem AAD's? With out having every instructor in the plane move around to turn off the other AAD's how would you get those units to cycle?Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
AndyMan 7 #11 May 25, 2010 QuoteHow about tandem AAD's? With out having every instructor in the plane move around to turn off the other AAD's how would you get those units to cycle? A quick reminder of basic firing parameters for Cypres, other AAD's vary slightly. Tandem: 1900 feet, 78 MPH (6,840 FPM). Expert: 750 feet, 78 MPH (6,840 FPM). Student: 750 feet, 29 MPH (2,552 FPM). Also, it might be a great time to remind folks that Mike Mullins tried to get an expert Cypres to fire by diving at grossly excessive speeds on descent - he could not. I am curious if he also tried with a tandem one...__ You put the fun in "funnel" - craichead. Quote Share this post Link to post Share on other sites
stratostar 5 #12 May 25, 2010 I've had to land a couple times with a full load of students wearing Jav's and it was not friendly to turing off due to location of unit head (as you know) so a quick reminder to a pilot (you know) who wouldn't need to be told, and we took our time and came down slow and easy..... never a problem. That said, if it was a rig were it could be reach with ease and turned off that is what I would do, if not easy to reach each one, I tell the the pilot and we go slow to landing.you can't pay for kids schoolin' with love of skydiving! ~ Airtwardo Quote Share this post Link to post Share on other sites
USPA 0 #13 May 25, 2010 Quote Student: 750 feet, 29 MPH (2,552 FPM). WRONG... student: 750 feet, 78 MPH (6,840 FPM). 1000 feet, between 29 MPH (2,552 FPM). and 78 MPH (6,840 FPM)The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
pilotdave 0 #14 May 25, 2010 I still don't know what it means that the student cypres fires at 1000 feet between 29 and 78 mph. If the student is doing 40 mph, it'll MAYBE fire? It just kinda fires when it feels like it? Today it'll pick 32 mph and tomorrow maybe 75? Why are the expert firing parameters so exact and the student parameters so broad? Seems to be that "between 29 mph and 78 mph" means pretty much the same thing as just "as low as 29 mph." If you're burning through 1000 feet at 120 mph, it won't fire? Since we know cypreses are calibrated for sitting in a burble behind a jumper, we're aware that even an expert cypres can fire as high as 1200 feet or so. Is a student cypres actually set to fire at a different altitude, or is it just that under a partial malfunction a student cypres set for 750 feet might fire as high as 1000? Is that why it won't fire at 1000 feet above 78 mph but will wait for 750 feet at that high a speed? So is it wrong to say an expert cypres fires at 750 feet and 78 mph? Is it wrong to say a student cypres fires at 750 feet and 29 mph? I think we should think of them both firing around 1000 feet. And as far as speeds, 78 and 29 mph seem to be the numbers to stick with. Dave Quote Share this post Link to post Share on other sites
billvon 2,406 #15 May 25, 2010 >I still don't know what it means that the student cypres fires at 1000 feet >between 29 and 78 mph. If the student is doing 40 mph, it'll MAYBE fire? No. 40 is between 29 and 78mph so it will fire. If the student was doing 120mph it will not fire until the 750 foot limit; if the student was doing 20mph it will not fire. Quote Share this post Link to post Share on other sites
USPA 0 #16 May 25, 2010 Hmmm... as an instructor you should really got more familiar with the gear you send you're student up with (presuming you have students using a student Cypres). Anyways to compliment my own and Billvon postings: If a student cypres goes 78 mph or faster, it will fire at 750 feet (or below). If a student cypres goes 29 mph or faster, but slower then 78 mph, it will fire at 1000 feet (or below).The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
riggerpaul 1 #17 May 25, 2010 QuoteHmmm... as an instructor you should really got more familiar with the gear you send you're student up with (presuming you have students using a student Cypres). Anyways to compliment my own and Billvon postings: If a student cypres goes 78 mph or faster, it will fire at 750 feet (or below). If a student cypres goes 29 mph or faster, but slower then 78 mph, it will fire at 1000 feet (or below). Though I understand what the parameters mean, I still don't quite appreciate certain aspects of this split personality. Here's what the CYPRES2 manual says -The Student CYPRES can be recognized by the yellow button with the imprint „Student“ on the control unit. It activates the release unit when it detects a rate of descent higher than 29 mph (13 meters per second). The activation altitude is split. In the case of rate of descent being approx. that of free fall, the opening altitude is at approx. 750 feet (the same as with Expert CYPRES). However, should the rate of descent be lower than that of freefall but still above the limit of 29 mph (e.g. with partially opened canopy, or after a cutaway), then Student CYPRES activates the release unit when the altitude falls below approx. 1000 feet (approx. 300 meters) above ground level. The student will then have more time to prepare for landing. Like the Expert CYPRES, the Student CYPRES ceases operation below approx. 130 feet AGL.If the student should have more time to prepare for landing in the case of a partial canopy or a cutaway, why should he not also need/have the same time to prepare for landing in the case of a freefall activation? What benefit is there to waiting until 750 feet for a freefall activation? Part of me wants to think that this is so the instructors don't get a face full of the student's reserve should they be following him down to the basement. But, shouldn't the instructors be long gone by 1000 anyway? Quote Share this post Link to post Share on other sites
USPA 0 #18 May 25, 2010 Well you should ask Helmuth about that... But it is true that a 2 out situation in inherently more complicated then a reserver activation. (bear in mind that when Cypres was released, people associated AADs with unnecessary activations (the FXC wasn't as reliable as it is today) ) That being said, Airtec is the only manufacturer who uses the way of activation, Both Argus and Vigil (I/II) activate at 20 m/s (45 mph) at aprox. 1000 feet in student mode. The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
pilotdave 0 #19 May 26, 2010 Maybe you should read my post... I said exactly that. My thought is that the student cypres doesn't really have dual firing altitudes... or at least they don't particularly matter if they are really programmed in. As I said, we could just as easily say an expert cypres has dual firing altitudes. Either 750 feet in freefall, belly to earth, or up to 1200 feet or so upright or in clean air (no burble). If a student cypres was designed to activate in a burble at 29 mph at 750 feet, it'd probably fire a bit higher than that (1000 feet?) in clean air. On the other hand, it wouldn't fire that high in a belly to earth position at higher speeds because of the burble. But for the purpose of this thread, we shouldn't assume there'll be a burble behind the jumper since he's sitting in a plane. We shouldn't assume the advertised firing parameters apply. It would be more conservative to assume a student cypres enters its danger zone around 1000 feet (or even higher) and above 29 mph. I don't think we need to worry about speeds higher than 78 mph in a descent below 1000 feet, but I do wonder if a student cypres would fire at 100 mph at 1000 feet when inside a plane (no burble). So I'm just saying that your very specific answer about activation altitudes of the expert and student cypres might not be quite correct when it comes to a descending aircraft. Thoughts? Dave Quote Share this post Link to post Share on other sites
USPA 0 #20 May 26, 2010 *** Oh my, you are completely mistaken here and miss some fundamental understanding of how these devices are programmed. Cypres 1/2, Argus. Vigil I/II, aren't simple yes/no triggers measuring air-pressure. These devices have complex (relatively) algorithms to correct for a number of things such as Tumbling / controlled maneuvering and other then belly to earth free fall position. These algorithms van be fouled, first generation more easily then second generation, because the later have far more processing power, so can correct themselves way better/faster. Please make not that the student cypres does have 2 distinct activation parameters and although in the case of cypres it only measures air-pressure, going from air-pressure to actual height and from there to speed, is not trivial task and it shouldn't be assumed it's calibrated for normal freefall. There are some AAD representatives on this forum, maybe they could explain better then I can... The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
billvon 2,406 #21 May 26, 2010 >If the student should have more time to prepare for landing in the case of >a partial canopy or a cutaway, why should he not also need/have the same >time to prepare for landing in the case of a freefall activation? A few potential reasons: 1) Because reserves deploy slower at slower airspeeds. 2) Because the higher activation altitude might result in two-outs more often if it fired at freefall speeds. 3) The original Cypres both cut away the main and activated the reserve; I can see cases where that is better done at a high altitude during a mal than at a lower altitude. (i.e. massive spinner; this gives you time to kick out of the line twists on the reserve.) Not sure what his actual reason was. Personally I don't see much benefit in using a student cypres over an expert cypres for students (other than a bit of lawsuit insulation.) Quote Share this post Link to post Share on other sites
USPA 0 #22 May 26, 2010 Because you asked me to reread your post, I will go through it step by step. *** No, it WILL fire QuoteIt just kinda fires when it feels like it? No it fires when it measures a corrected speed above 13 m/s AND below 35 m/s at 1000 feet or lower, and at 750 feet or lower when it measures a corrected speed of 35 m/s or higher. QuoteToday it'll pick 32 mph and tomorrow maybe 75? No, see above QuoteWhy are the expert firing parameters so exact and the student parameters so broad? They aren't they are both very much exact, the student just has an extra "go" parameter. Quote Seems to be that "between 29 mph and 78 mph" means pretty much the same thing as just "as low as 29 mph." No, it doesn't. It means that when speed is higher then 78 mph / 35 m/s it won't fire until 750 feet. Quote If you're burning through 1000 feet at 120 mph, it won't fire? No since speed is higher then 78 mph / 35 m/s it won't fire until 750 feet. Quote Since we know cypreses are calibrated for sitting in a burble behind a jumper, we're aware that even an expert cypres can fire as high as 1200 feet or so. AADs are calibrated for a fast array of things, among which it's burble. In the first generation device, with way less computing power then the current iterations, an sudden upright position at aprox. 1050 feet or lower, could trigger a fire. Although not impossible with the current AADs, this has become way more unlikely. Most often people site 1250 feet, because you can still see that on your altimeter, but the true correction is aprox. 300 feet in the first generation devices. QuoteIs a student cypres actually set to fire at a different altitude, or is it just that under a partial malfunction a student cypres set for 750 feet might fire as high as 1000? Yes, it is actually set with different activation settings. A partial malfunction, resulting in an upright position, but with a speed of 35 m/s or above, will not trigger a fire until 750 feet. QuoteIs that why it won't fire at 1000 feet above 78 mph but will wait for 750 feet at that high a speed? No, see above QuoteSo is it wrong to say an expert cypres fires at 750 feet and 78 mph? No, this is correct QuoteIs it wrong to say a student cypres fires at 750 feet and 29 mph? Depends on what you mean, yes it will fire at 750 feet and a speed of 29 mph / 13 m/s. But it that speed is obtained at 1000 feet or lower (but of course above 130 feet) and speed isn't above 78 mph / 35 m/s, it will fire. If speed is 35 m/s or above, it will only fire at 750 feet or lower (of course again above 130 feet). QuoteI think we should think of them both firing around 1000 feet. And as far as speeds, 78 and 29 mph seem to be the numbers to stick with. Sorry but you thought wrong. It is based on lack of knowledge of your own, and your students gear.The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die... Quote Share this post Link to post Share on other sites
sundevil777 94 #23 May 26, 2010 QuoteThe original Cypres both cut away the main and activated the reserve ?People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
skinnay 0 #24 May 26, 2010 QuoteHow can you turn off a cypres after it's already been activated? The exact same way you turn it on? Quote Share this post Link to post Share on other sites
AndyMan 7 #25 May 26, 2010 QuoteWRONG... student: 750 feet, 78 MPH (6,840 FPM). 1000 feet, between 29 MPH (2,552 FPM). and 78 MPH (6,840 FPM) Guilty. In my defense, as an AFF-I for 4 years and a Senior Rigger for 2, I still have never actually seen one of these things. Amazing! A good thing, IMHO - I do prefer the simpler algorithms of the other models and brands. To get back on point, With a Student Cypres, the pilot of a descending aircraft must keep the VSI well below 2500 FPM, and should be reminded of such. With only Expert or Tandem AAD's on the plane, the pilot must keep the VSI needle below 7000 FPM - something I hope he doesn't need to be reminded of. _Am__ You put the fun in "funnel" - craichead. Quote Share this post Link to post Share on other sites
