ericfradet

it is because the head of the student should be just below pilot's head level instead to be so low with Sigma passenger tandem, the reason why it is so low it is because the UPT tandem passenger harness is NOT a good one, it does not hold the top of the body in freefall (except by snaps) and it already put pressure on pilot's chest, I fixed both issues as you can see in the picture

if manufacturer like UPT was really doing their job, by offering a product allowing to seat the student without being his ass in the ground, you should not have this problem !

do we consider the guy on the right carrying the first piggy back, it looks like , is not it ?

According to some correspondence with the folks at Wings, it is not Eric's system. _____________________________________________ Sorry Jerry, but I can definetly tell : watching the "Boost packing instruction" this is my design, there are many différents ways to realize the interlock but the Boost system falls Under my patent, for the same reason in the past I already forced Mirage to not use the DRX without an agreement and I will do the same with Wings...I am not very happy with manufacturers using other people ideas to make buisness with it...I would rather recommand them to do it with someone else !

you are right.... I specially changed my mind for Tandem rides….I think it is a lesser evil in Tandem, specially with the Tandem reactive canopies coming in the market.The MARD put pretty much the reserve right where the main just was (of course if you cutaway with the main still in the bag, this last one will probably hit the just inflated reserve but without big damage on videos I have done so far) .The MARD help to yield beautifully straight and even line groups at line stretch.With a simple RSL, a pilot chute always deploys your reserve with the relative wind. This becomes a very important difference when the pair breakaway from a spinning malfunction. Without the MARD, the pair must "be stable" at the reserve opening time, this is a situation you are not sure to occur in a tandem configuration with the stress of cutting away, a chance the pilot does not grab the passenger legs like it is asked in the books….and the possibility the pilot chute does not work properly (burble or delay), while the pair tries to align bodies into the relative wind to make it is safe to deploy the reserve, without an angle to they do not risk entanglement with the deploying reserve, or having "unequal" reserve line lengths at line stretch, risking a spinning reserve opening with line twists. Even if with a spinning main malfunction due to reactive new canopies, you still have a chance to rotate under the reserve with a MARD, at the end I think the MARD is worth for tandem use only…

you are right, the device is mine, here you go : http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=7&ND=3&adjacent=true&locale=fr_FR&FT=D&date=20090520&CC=EP&NR=2060488A2&KC=A2#

***The CYPRES cutter location seems to be the issue here not the top flap design. Because of my job, I have been experimenting rigs with the top reserve flap tucked down into a pouch on the reserve bottom flap like it is common on most of the rigs nowadays, the top flap did not come out of the pouch so the container did not open because many reasons. All I can say, I have had all these several rigs (from the same company) with tuck-down flaps total when bench tested with an AAD cutter located on top of reserve PC or even when the ripcord was pulled out. It did not stay close for ever, but for several seconds, and when the PC finally went through, it did not have enough power to launch properly without causing a severe delay to the reserve deployment.

in fact the real name from the russian engineer is Sanfirov, not sanfronov, here is the original link from where it comes from: http://forum.blockhaus.ru/index.php?showtopic=13998

I am very interested to know , where did you find this picture ? ! so far in France, we believed that Leo Valentin was the first one to use rigid wings in the years 50..do we have any testimony from some russian jumpers who were withness from the jump ? I have to say that we do not know much about russian parachute history..

you are suppose to know this one !

PDF was doing this one also, and found some delay in some circunstances and difficult maintenance

I have the same feeling like Rob, cause it is just the big number of use

in the past because a bad angle for the wires in between the control unit and the processing unit, was one reason it could happen that the Cypres had problem to turn on, it is a reason why Rigging Innovations did not permit the control unit on the front of the rig. and a reason why the Student Cypres has a longer wire.

abolutly not, they just moved production and managment, they are not at Cergy pontoise anymore