AIAA has been running these for years, and any team would almost certainly look at what worked in the past, but this hand launch is something quite different.
Other than adding a high degree of difficulty to the usual tasks, I see no point to it.

Or they just need to include a reference to this thread as part of their bibliography....

You'll notice that I've been careful NOT to actually draw up the model for them. Instead I've analyzed and discussed the different factors only and suggested where the more important limitations in this design exercise would be. It's still up to them to test for the factors and determine just how heavy they can make it and still step up to the line with a good chance of at least making it safely into the air.

Paul, assuming that this IS all done on one charge it forces a rather interesting extra decision load. Clearly the charge will be limited but it is certainly a doable exercise. There's easily enough energy in that 1 lb load to achieve all three tasks. Now they won't all be done at full throttle because the team and pilot will need to allocate how much energy is used in each mission and try to dole it out in a manner that maximizes the scoring. It's as much about making hard decisions at the throttle so that there's enough energy left at the end as it is about being limited by the launcher's ability to get the model airborne. All in all a highly interesting challenge. It's enough to make me wish I were still back at school and able to be on one of these teams.

Ok.....just don't come up with anything good........I've gotta fly another university's plane...(and I am a sore loser)...

Well, I do help the team....but bite my lip and let them do their thing when it comes to design....sometimes it hurts when they calculate something WAY wrong....but they learn lots about the consequences!

This year with the "spear" throwing contest it should be interesting...I wonder how fast a college javelin thrower can toss a plane? The planes the teams I fly for have ended up with good designs..but the hardware has let them down...motors and gearboxes...(ouch!) Last year the teams would have done pretty well but...broke 3 power units...

It is actually a pretty good show...lots of crashes...fires...etc.

Tall Paul, you are right, the batteries can be recharged between flights, just not during one attempt (i.e. a failed launch, cannot go and top-off the batteries before next launch but if failed flight attempt, can go top off batteries while waiting turn in line)

Guys/gals,

We really do appreciate the pointers here and Iwill share them with my team!

Do not worry (Doc), we will do the design ourselves. We just wanted to get some preliminary numbers so we wouldn't spend a month messing around in a totally different range of weights/wing loadings.

Iwill champion the inclusion of this forum in our works cited page in our report however Icannot make any guarantees.

Again, Thank you for your unlimited interest in our design!

I will post the final results/specs in April after the competition.

Check out combat planes in the ssc class for a few ideas on hand launched durable electric designs. Not having read the specs,I would believe the application might be a soldier launched recon plane type thing. something compact, easily put together and durable reminds me of the e-ssc planes a few have built for combat at about 2lb 8oz. everything there is hand launch. A couple of the designs, the old 1072 avenger used to do real well in climb and glide withthe old os25 but would be heavier at a 3.5# max weight.

Probably not what your looking for but combat and glider stuff is probably a good source of hand launch info.

Aw shucks! That takes all the fun out of it! ! ! !

I actually did some power to weight calculations that I didn't post just for myself. And with a 12 volt 2200 mah pack it would be possible to do all three missions from one charge but only with some thoughtful planning on which tasks to use how much power and how fast you'd fly the load bearing missions. I thought that between the requirement for the hand launch and careful doling out of the power that this would make for a highly challenging event. Now I find that I read the rules wrong and there will be more than enough power on board to do all the missions easily. So we're back to the guy doing the javelin launch and the pilot's ability to correct for any faults in time being the only real limit to plane and load.

You want to get that guy chosen and onto a high quality steroid diet pronto to be up to snuff for the final meet.....

After the 2001 SAE contest here, the fuel on board rule was changed for multi-motored planes.
It had been interpreted as 4 ounces total.
For the multis, which used 4 motors, this meant only 1 oz per motor, which led to some magnificent choreography on engine start, with all 4 starting at the same time, and the plane released immediately, hoping the motors wouldn't conk out in flight. They tended to, which wiped some really expensive airplanes, so the next year the rule was changed to 4 oz per motor, which made more sense safety wise, and cut down the number of crew persons needed to operate the plane.

I could tell all they were wanting was "data"....the combat planes would be a good choice...good idea....maybe some of the "pattern type" planes of old would be a good source of data also.

What has been my experience with the AIAA contest is the "high wing loaded" aircraft that you can actually fly...and fly well...once you get used to them just barely climbing out.
Some of them have been 12 or so lbf with 500 in*in of area...!

Steve

I'm just a beginner at this, but based on my meager experience, the higher the wing loading, the faster it has to fly to develop enough lift to fly.  I have been told by Pat Tritle (RC plane designer) that, "Light is Right".  The lighter the plane, the slower it can go, and the easier it flies.<div>
</div><div>BUT...lightweight park fliers won't tolerate a lot of wind.  I live in a very windy area, so I have better luck with moderate wing loading and stronger motors to better be able to penetrate the wind.</div><div>
</div><div>It seems to me that most of the foamy ARFs, which are great trainers because they can be so tough, are also moderately heavy, with 22 to 24 ounces pretty typical.  My first real successful trainer, the Multiplex Easy Star, weighed in about 24 oz and only had a brushed Speed 400, barely powerful enough to EVENTUALLY get up to altitude, but can't handle more than about 10 mph breezes.  </div><div>
</div><div>Maybe I'm rambling a little bit.  I am just barely a novice at flying, and just sharing what little I know.</div>