(1) It could suffer damage on opening that makes it impossible to land safely.
(2) It could open OK, but the jumper may not be able to flare and land it properly. A highly loaded reserve will not handle like a highly loaded modern ZP main.
These things COULD happen. Of course, lots of jumpers overload their reserves to varying degrees and deploy and land them OK. On the other hand, several jumpers have suffered injury or death from overloading reserves.
The other danger area with reserve specifications is deployment speed. A reserve deployed at high speed can either fail structurally or cause the jumper to fail structurally. This has also caused fatalities.
It seems that most of the experienced jumpers I know overload their canopies. This includes both the main and the reserve. Why does it make more of a difference if you overload the reserve? (Besides the obvious reason / it is your last line of defense when dealing with a malfunction) When jumpers overload their canopies, it in most cases exceeds the manufacturers maximum weight limit by a substantial amount. If anyone has more information or details please share.
I asked this very same question to my rigger when I bought a new reserve recently (used one, not a *new* one) and he said...
"All reserves are drop tested to 254lbs" , so that overloading their "recommended" weights would have very little impact.
My concern still lies in the fact that 1) you may be going quite fast and deploying a reserve close to or over its weight limit (from what I know about physics) coupled with your velocity, may OVER-overload it and cause it to mal as well 2) you never know what kind of a mal you're gonna have so it is always difficult to judge how you are gonna need it.
So, I don't know if you can "concretely" say that overloading a reserve is still okay, but I guess that is why the factory *recommends* loading at certain weights. They have already done all the math involved.
Be careful with that. Are they all built the same? Nope. Are they really all drop tested with a 254 pound weight? Maybe. Is that what TSO calls for? I'm not sure. Is that a 3 second delay? what is the speed at which the object is falling? What altitude is it tested at? (A loading at sea level will have very different consequences than jumping at a 5000 msl DZ!) I would ask PD, Precision, Tempo etc what they had to say about testing (I think there is something on the first two's website about reserve loading). I recommend more homework before deciding how heavy to load a canopy (main or reserve). But hey, it's your butt in the harness, you make the decision.
Just to clarify. All reserves built under TSO C23C or C23D had to prove that they would survive openings at 254 pounds going 150 knots near sea level, etc. A few large reserves have been certifed under TSO C23D to heavier weights, for example, Precision's Raven 282-M is certified for about 292 pounds at sea level. Most manufacturers publish lighter weight limits on their reserves because they do not expect the average jumper's ankles to survive landing a tiny reserve. Finally, to quote Al Frisby: "There is no point in packing a Cypres and a tiny reserve into the same container, because even if the Cypres saves your @#$%^&*, the landing will kill you!"
So then...riggerrob...are there any reserves you would feel more comfortable overloading than others.
e.g. I use a Swift Plus 145 and at almost 200 out the door, this is about 1.38p/p/in2. My rigger claims he doesn't like Swifts because they don't use a hot knife to cut the fabric so you get lots of strands of loose thread coming out. Does this affect the wear of the reserve at all? He is a big fan of Raven and PD (as are most jumpers), but is there anything really wrong with this??
PD reserve's are built stronger then most other reserve's. The reason the pack volume is larger on a PD reserve is because there is extra re-enforcemant tape and double stitching on the critical seams. I jump a PD-160R at a wing loading of about 1.1:1. I've never had to use it but I've repacked it enough times that I'd feel comfortable jumping it at a much higher loading. I've repacked a Tempo and I'm not sure I'd use it at anything above 1.5:1. The canopy just seemed to be flimsy compaired to the PD. Just one Rigger-in-training's feelings.
Not that I would recommend loading any F-111 canopy beyond 1.3 pounds per square foot ... and loading a Tempo at 1.5 is just plain dumb! I feel more comfortable overloading reserves that have spanwise reinforcing tapes: Amigo, PD and possibly the latest Ravens. I weight about 220 pounds out the door and wear an Amigo 172 reserve. As for Swift Plus construction techniques. Yes the cold-cut edges will fray sooner, but your canopy will fall out of fashion long before that becomes an issue. A more important issue is the exposed hot-cut edges of the non-loaded ribs in the Swift Plus. These will start to fray after a few hundred deployments. Non-loaded ribs on early SET 400s also have exposed hot-cut edges and they start to fray after about 300 jumps. Mind you, if you plan on putting a few hundred jumps on your reserve, I question your packing techinque!