Going For Broke And Getting Your Wish

Sunday’s last flight round showed that many teams pushed the limits and beyond. Only three Advanced Class aircraft made it safely around the circuit; one couldn’t lift off, and the other four crashed, some in spectacular fashion.

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The more payload you fly, the more points you earn. Load too heavy and you stay on the ground or risk structural failure. That means your wings fold up, you can’t get enough altitude to clear that tree, or you head for a swim.

The Miners thought their Data Acquisition System (DAS) was finally working properly but we’ll never know for sure. Their attempt at a 30-lb payload, larger than any other team’s, bent the nose gear on take-off causing the prop to hit the ground and ended their chances for victory. One of the guys claimed the DAS was finally working perfectly, and had that flight succeeded, S&T might well have claimed top honors.

We had a reliable plane but 2010 marks first time SAE factored in automation to each aircraft’s performance. The long-term goal, we understand, it to make these planes autonomous, the first step of which is for the DAS to measure each airplane’s take-off roll. The theory was that whichever craft lifted off closest to the 200-ft mark would gain the most points, and that would be used as a hefty multiplier of your cargo weight. We are not sure if the accuracy of the data was much of a factor, as much as whether the planes could measure much of anything. Crash 2.jpg

The Miner’s DAS consistently worked in the lab, but flight conditions were more challenging. The pavement had some bumps in it which magnified the effect of Favonius‘ tire-free aluminum wheels. Many planes used similar wheels attempting to save weight, but those airplanes seem to have less control on landing and takeoff, as well as suffering more vibration damage.

S&T’s Pluto electric-powered micro-class airplane, only flew on Day 1 but that was enough to earn 3rd place in that category. That crew had to hustle back to Missouri in time for work early Monday morning.
In the top-level Advanced Class the Miners took 2nd place in the design category and by Sunday morning had already lifted only 4 ounces less than overall winner Warsaw, Poland. Their last-minute attempt, described above, to lift the event’s biggest payload could have won the event had the DAS finally worked right but Iowa State, reportedly one of only two teams with a reliable DAS, slipped past S&T, taking 4th place on their final flight and leaving the Miners in 5th.

You’d think that watching a year’s worth of work turn to matchsticks would be a crushing feeling, but that isn’t the case. These builders tend to panic as their projects begin to go out of control, but once the crash flight comes to a splintered end, most teams laugh about it. The overall atmosphere is pretty light-hearted, even among the Thunderbird Field hosts. Crash 3.jpgIt is almost a point of pride to win the “Best Crash” award each year, and when the ‘meat wagon’ hauls your bird from the woods or lake, it is not a time of serious mourning. Everyone seems to acknowledge that R/C aircraft is a high-mortality hobby. It’s not a case of if you are going to crash, but when.
Trophies and bragging rights are nice, but the real prize is the learning that takes place. DSC_0706a.jpg

The teams are eager to share their designs more as hobbyists than competitors. You get professional evaluation of your projects, network with future co-workers and possibly employers, and earn a sense of pride for what worked and learn to fix what didn’t. Like many other contests it is more about systems engineering than it is airplanes. Aircraft are really just a byproduct of the process we call experiential learning.

P.S. Almost forgot that one team arrived in Ft Worth, opened their trailer to find a cabinet had fallen on their plane, completely destroying it. They closed their trailer door, said “see ya next year!”, and headed home.

Stuff happens.

Airport Attrition, Part Two

DSC_0548a.jpgThere will be only two flying rotations today, but just two hours into the first cycle at least half a dozen planes have crashed. We’ll get back that in a minute, but S&T’s Advanced Aircraft had a GREAT early flight. The DAS finally worked well enough to make it a legal sortie, but not well enough to to earn bonus points. That means the Miners’ 25.6 lb cargo weight rolls into to their overall score.
After each flight the teams must weigh the cargo and let the judges check over each aircraft. Now that the headwind has picked up, S&T might go for broke by taking on the maximum possible payload of 30 lbs. That could get them a lot of points (especially if the DAS works), or it may mean the plane will fit in a much smaller vehicle on the way home.
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Speaking of crashes, the official definition of a successful landing is that even if a plane smacks the runway, everything remains attached. Cincinnati’s final flight just ended with a crushing landing that broke their plane’s back, but it still stayed connected. They claimed to “fly it to the max”, which is what this event is all about.
The early crashes can be attributed to calm early-morning winds and each team’s attempt to fly heavier payloads. As the payloads increase, these airplanes either fail to launch, plunge to the ground, or struggle through a complete flight. Most, if not all the planes that smashed to the ground yesterday have risen from a pile of junk and been rebuilt overnight. After a successful flight one giddy student said “after a flight like that we don’t need any sleep!”

Airborne Attrition*, Part One

The Texas weather was wonderful today. Cool, low clouds, nice steady breeze from the north, and no rain, making flying easy. Sixty five colleges registered for the event and only six failed to show up, so it was a very busy flight line. First in line were the micro aircraft, then dozens of regular planes, and finally the advanced birds heading into the air. The breeze helped most of the early craft jump into the air, easy to do because during the first cycle none of the them carried any payload.DSC_0630.jpg Pluto, S&T’s micro aircraft, flew gracefully, but once the Miners started adding payload flightline staff could hear the plane creaking and groaning as it went by. The more payload, the more noise it made. Pressed for an explanation, one student said (with a smile) “it’s just compensating for the cargo stress.”
New to the Advanced Class is a mandatory Data Acquisition System (DAS) that measures each plane’s take-off roll. Problem is, you could fly a 25-lb payload all around the airfield, but if the DAS malfunctioned and said you never took off, that’s what the judges believe, despite witnesses and photographic evidence to the contrary. Nothing personal, that’s just the rules. Favonia’s first flight was aborted when the front wheel snapped. Once the Miners made repairs it was back in line loaded with 25 lbs of lead. It lifted off nicely and handled the flight without a hitch, but when the judges checked the DAS, it claimed the plane had never left earth. Turns out the DAS chip had rattled completely out of it’s mount. It wasn’t there to handle the data so it was ruled an illegal flight.
Late in the day when students were loading their airplanes as heavy as they’d dare, the wind quit and robbed many teams of much-needed lift. In plain English, the craft taxied more than they flew. That meant Favonia was 0-for-3 in the flight scoring, leaving the Miners in 5th place in the advanced group. They still have Sunday’s flights to fix the DAS and haul the craft’s design weight. If the DAS works right, the Miners have a good chance of overtaking powerful Sao Paulo, Brazil for first place. Meanwhile S&T’s micro-class Pluto is hanging in there in 3rd place.
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Oddly enough the most technologically advanced airplane was a carbon-fiber Canadian gem (at right) that flew beautifully, but was very tough to land. Twice it fought its pilot, ending up with the dreaded DQ (disqualified) label because it spun into the forbidden zone dangerously close to the spectators.
DSC_0538_2a.jpgOur Polish friends won high praise for innovative thinking and lots of creativity, mostly for a massive mylar-covered craft that sported a huge canard. That kind of risk taking means everybody comes out to watch because of a much greater likelihood of a short flight, otherwise known as a crash. It turned out to be far more stable than expected and flew several times.
*Lest we forget our attrition comment, two planes crashed in the lake, at least four hit trees, several pancaked into a field, a few flew straight into the ground, and there was one in-flight structural failure. Some of those have already been repaired and returned to service.
More fun tomorrow.

Flying Into Thunderstorms?

It’s just after 6:00 a.m. and huge storms have just swept through the Dallas Metroplex. It’s calm now but more storms are brewing to the west.
Please give some thought to how balsa and monocote will do in a thunderstorm.

Hotels Do Not Good Airplane Hangars Make

DSC_9858_2ab.jpgDSC_9893b.jpgThe Society of Automotive Engineers (SAE) is hosting their Aero East* competition in Ft Worth, TX this weekend, and the hotel you might use for a wedding reception is now cluttered with aircraft of all shapes and size. Teams from Poland, Puerto Rico, India, Canada, Brazil and all over the U.S. are uncrating their birds for mandatory tech inspections. Volunteer judges make sure each plane’s cargo area meets design specs, that radio controls work, and even school names are properly applied. DSC_9703_2.jpgS&T’s Favonius, while weighing a scant 15 lbs**, is certainly one of the biggest aircraft, partly because it features a blended wing body. The wing can’t be removed from the fuselage because they are one and the same, and the tail boom is also integral to the plane: it can’t be taken off. This makes for a very strong aircraft, but it’s a real pain to move it through narrow hallways and doors en route to inspection and presentation rooms.
If you followed Monday’s last-minute test flight you may notice that Favonius sports some new tail feathers. The Miners discovered the tail boom had way too much torsional flexibility, so when the pilot told the plane to turn, the tail had a nasty tendency to rotate in place rather than redirect the aircraft. That might be OK for recreational flying, but these are cargo aircraft. Heavy cargo aircraft. And they fly in the spring-time skies of Texas, which means turbulence, and lots of it.
The AAVG team fed the test flight results into a computer, calculated Tornado Alley’s meteorological tendencies, added the cost of embarrassing themselves, and realized “This ain’t gonna work.” It took just two days for the aero Miners to reinforce the tail boom before packing the trailer and hitting the road. One judge even complimented the aircrew on their imaginative use of Boy Scout knots that strengthen the new joints.
The micro planes begin the two-day flying fest early tomorrow. These delicate electric mosquitos are susceptible to wind gusts, and are known to go “POOF” for no apparent reason and return to earth like autumn leaves in the breeze.
The larger craft, weather permitting, will launch later in the day and keep adding cargo weight until they crash, can’t take off, or win the day.
*Why the east competition is held well west of the Mississippi, is, as the King used to say, “A puzzlement.”
** The new boom jumps Favonius’ up from 13.4 lbs empty weight to just under 15 lbs. Still very light for such a large airplane,

It’s Alive! It’s Alive!

DSC_0018a.jpgWith apologies to Gene Wilder and Peter Boyle, the beast has finally come to life.
Advanced Aero’s Heavy Lift Aircraft, Favonius, rose from the runway yesterday, overcoming weeks of weather delays, a busted engine, a shattered prop caused by an errant finger, and no small amount of jitters to see if Monday’s winds and rain would abate.
The air crew scheduled this test flight just three days before leaving for competition, which means in event of a malfunction there are just 72 hours left for the glue to dry on an aircraft overhaul. Dark clouds and high winds plagued central Missouri for nearly a week before this last ditch, uh, attempt, but St. Patrick must have called in a favor because the breeze stilled and the sun popped out at the Cuba International Jetpark, if only for just a few minutes.
Team pilot Matt Walter (praying, at right) ran through his checklist and applied both throttle and a little body english as the bird did its best VTOL imitation. Matt had his hands full with the revived crosswinds and managed to swing it through two nerve-wracking circuits around the airfield. When Matt was bringing the plane back down he was shocked to find a camera-toting idiot, who wanted just a little better view of the flight, standing on runway center. And the photographer decided it was time high-tail it out of there just before the plane flashed past. FAA calls that a “runway incident” we think; never mind what the team called it. Either way, the plane ran out of fuel just as it set down on the asphalt (whew!).
Crew chief Tim Peters says “the airplane itself weighs 13.5 pounds and we flew with 16.5 pounds. That’s a total aircraft weight of 30 pounds. We’ve decided to utilize a space truss, an AAVG trademark in years past. My estimate says it will add between 0.5 and 0.75 pounds to the empty weight of the airplane. Also, no fingers were lost in our endeavors.”
Let’s hope that holds true during this weekend’s SAE Aero contest near Ft Worth, TX.
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p.s. Matt coined the term “entropy generator” for the plane’s secret design. Entropy is the thermodynamic construct that prevents perpetual motion machines from working. Got it?
p.p.s. Despite comments from flight-line observers, Favonius is NOT Latin for “Flexible Flyer”. Any resemblance to the iconic sled is purely coincidental, despite the aircraft’s habit of having the wings and horizontal stabilizer functioning on non-parallel, uh, planes (sorry!).

What Goes Up Comes Down Somewhere, or “Kansas Lawn Darts”

6 Prelaunch set-up4_2.jpg Four years ago the S&T Advanced Aero Vehicle Group started a rocket team to expand from its heavy-lift airplane mission. They competed in the NASA-sponsored University Student Launch Initiative (USLI) for the past two years and were planning for the third time, but things just haven’t worked out.
NASA now insists that you have proof of a successful launch before you show up at Huntsville, Alabama, ’cause they don’t want rockets going anywhere but straight up. The Miners’ first test launch last month resulted in the loss of part of the second-stage dart, or “sustainer” rocket. They conducted a launch post mortem, but without all of the body parts, it was a somewhat speculative venture.
Armed with a hastily-rebuilt top stage, Steve Berg and crew headed back to Kansas on a last-ditch attempt to get back in the game. Team leader Mike Crance takes it from there:
“We launched a two-stage rocket this year, with the scientific payload in the second stage, known as the sustainer. The sustainer had angled fins to “spin-stabilize” the rocket in flight. We were trying to find out if by using smaller angled fins, the weight reduction would offset the fins’ drag.”
“It was an ambitious project, but we were able to get the ‘hard’ part working almost perfectly–the separation of the two stages worked every time. For some reason, the electronics in the sustainer kept failing/malfunctioning and since we were never able to recover that section of the sustainer, we can’t determine what went wrong up there.”
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“Saturday before the rocket was even stacked and on the pad, the altimeter failed. Our last chance for a successful flight depended on our back-up trigger, a simple timer, so we decided to launch and cross our fingers. The rocket blasted off beautifully, separated at 1,000 feet and continued to roughly a mile high (way out of visual range for the little sustainer). The booster’s recovery systems functioned perfectly, dropping it back only 100 yards from the pad. The sustainer flew without the telltale wobble of an unstable rocket, so we assume that the angled fins worked, but then we heard the first of two important “pops” that would indicate proper separation. Problem was we never heard the pop of the parachute ejection charge. Sounds like the timer worked but beyond that, we have no idea what happened. Could have been a wire or battery came loose, the second charge simply failed, the first charge damaged the electronics, etc. Who knows? Since it’s probably sitting fins-up in someone’s distant yard, we’ll never know exactly what happened.”
“Meanwhile, since the booster and separation worked fine this year we may use at least that portion of the rocket again in 2011, but AAVG won’t be going to Huntsville this year.”

And We Have Lift Off! or…..Why We Test

Two weeks in a row Zephyrus didn’t make it off the ground, and the third time didn’t look like it was going to be the charm, either.
Week #1 was spoiled by the spring thaw. The site was too muddy for vehicle access; they might have gotten in, but probably wouldn’t have gotten out.
Week #2 was too rainy to fly at Pittsburg, KS.
Week #3 had a late winter storm roaring out of Kansas, but with practice time slipping away the Miners forged ahead anyway.
RocketFSCN3462_2.jpgSteve Berg, AAVG’s version of Werner von Braun, reports that “Dave Althuis, Reid Young and I traveled to Argonia, KS this past weekend to conduct the rocket’s first test launch. We ended up launching at 5:30 CST into roughly 19 mph winds. The rocket flew as expected to an altitude of 1000 ft, where it released the sustainer (second stage -ed.)The sustainer motor fired successfully and continued to an altitude of 5280+ ft. The booster deployed its parachute and landed safely roughly only 100 yards from the launch tower.”
“The sustainer, however, was not as successful. Due to an altimeter malfunction both the drogue and main parachutes were deployed at apogee, and the sustainer broke in half. The lower section smashed to the ground and survived with no damage (quite impressive), but the upper portion remained attached to the parachute, and because it was much lighter than the entire unit, blew deep into the land of Oz. After a couple hours of searching we decided to pack it in and head back to Rolla.”
“We’ll have to do another test launch or we probably won’t pass NASA’s safety inspection in Huntsville, AL, next month. The replacement parts will arrive during spring break (I hope). We have added some modifications to alleviate the problems we had at the test launch, and are highly confident that the second flight will be successful. The plan is to launch April 3, with April 10-11 as a rainout date.”
Steve sums it up nicely when he says:
“We got the up part right, now let’s get the down part right, too.”
As an afterthought, there weren’t any objects in the sky to interfere with the rocket’s flight. It’s a little early for migratory overflights, and Northern Iowa’s Panthers apparently caught all the Jayhawks dozing on the ground, ’cause the only evidence of the squawker was scattered remnants of blue and crimson feathers wafting in the breeze.
One of those times when it’s kinda fun to have a KU grad in the family.

St. Pat’s Is A Big Weekend in Rolla

AAVGWork2jpg_2.jpgSo your first response is “Well, DUH!”
Everybody knows about painting the streets green, the Follies, Gonzo Games,manure spreader, coronation, honorary knights, the parade, dozens of couches sprouting on the lawns, porches and sidewalks all over town, and glasses lifted high to mourn the passing of “Alice”.
St. Pat’s is also a milestone for many of S&T’s student design teams. Most groups plan to have their projects at least operational by mid-March so they can get on with testing, and some are scrambling to make that goal. We already know that AAVG’s rocket is ready to go, the concrete canoe floats, Formula SAE broke traction on their car last night and the Human Powered Vehicle’s prototype chassis is done and tested and the fairing is nearly complete. No word yet if Baja will run their car up Pine Street in Saturday’s parade, but the BIG story is Solar Miner VII, S&T’s redesigned solar race car.
SMVII will be ceremoniously unveiled 3:00 p.m. Saturday afternoon in Leach Theater of Castleman Hall. Solar car alum, fans, and team members will gather to toast the team that helped put S&T’s vaunted design teams on the international stage, and celebrate the fact that the 2010 solar car race will swing through Missouri.
This sleek new design won’t look much like its ancestors, and that’s all we’re permitted to say at this point. It’ll ride in the parade on a flatbed trailer flanked by team members, but like at the GM testing grounds it’ll be shrouded and unrecognizable. Think of it as a tease………………
Come to the unveiling ceremony! Help support the students! Volunteer to work the overnight stage stop in Rolla on June 23rd~

Advanced Aero Vehicle Group Set To Launch Rocket

When you build a 10 ft-tall rocket, you can’t just pick a nearby public park to test it. Should it explode or go out of control the collateral damage could be a little messy. If it goes too high you’ll quickly find that the FAA, TSA, Homeland Security and all other federal alphabet agencies don’t have much of a sense of humor.
Last week the AAVG rocket squad had to cancel a long-planned test launch near Elsberry, MO because the spring thaw left the site too muddy to reach. The “rain” date is this Saturday, when hard-core aero students pass up the St Pat’s parade and other liquid festivities to head to far-off Pittsburg, KS. Apparently even commercial aircraft avoid that Gorilla-infested area so it’s perfect for sending large darts skyward. After all, if you shoot down a Jayhawk, it’s OK. There’s no bag limit or closed season, and if you cross the line back into Missouri there’s even a bounty on ’em.
We hope to have photos from the weekend trip, but in the meantime team leader Mike Crance tells us the team has christened the three project vehicles.
The rocket is Zephyrus, the Greek god of the west wind.
Advanced Class airplane? Favonius, one of the Roman wind gods, who held dominion over plants and flowers and was generally equated with the Greek god Zephyrus.
Micro Class Airplane–Pluto. A cartoon dog.