Crashing and What to Learn From It

I've been working hard to try and figure out this center of gravity deal. After enduring half a dozen crashes I finally got it right: I threw the airplane, the thrust was perfect, it was going just fine until... I pulled up and it went down. Thats right, my control surface orientation for my elevator was reversed. By the time I realized what had happened it was too late, and the MTP made its final landing, straight into the ground.

So if you've made changes to your airplane's control surface in anyway; your servo hookups, your control horn location, your transmitter settings, heck, every time you go to fly, just do a quick sanity check on your control surfaces, when you pull up, does your elevator go up too, etc...

I'm glad I made this mistake on a cheap airplane that could easily be rebuilt. I've got to experience these kinds of mistakes early so that as my models get more complex and expensive my simple errors will have been worked out my system.

I also learned that on a new model, put the CG a little nose heavy until you figure out where it should be, error on CG being t nose heavy. It appears that nose heavy is a lot more manageable than tail heavy, which is about as guaranteed to kill your airplane as it can get. I'm still amazing how much CG affects performance.

I also am falling out of love with Hot Glue. Its great stuff for a lot of reasons, I did entire episode on it a while back to prove that point. But, here in Arkansas, even when my model is in the trunk on my car, it gets hot enough (about 95 degrees Fahrenheit) to damage anything under some kind of pressure, where the hot glue will just fail.

I think I'll slowly move to some CA foam safe glue as I get a little better at not crashing everything I build in the first 5 seconds of my flight.

I had a thought this morning about your 5 year plan. Flying across the US is much the same feat as flying across the Atlantic like the great Maynard Hill accomplished. Perhaps you could do this on the anniveersary of the launch for TAM as a tribute.

The TAM flight took 1883miles to cross the Atlantic with less than 1 gallon of fuel. With many accessories being run from the engine system too dragging the efficiency down. Your US flight will need to cover approximately 2500 miles. The TAM flight was a huge challenge but a US flight is a gargantuan challenge so everything must be at its best which is where I started thinking.

The TAM flight was complete on August 10 2003, we have had 8 more years of advances since then to aid you effort.

Engines are smaller, more powerful, more efficient with a raft of tuning options to help get everything right for the seasoned tinkerer (I mean petrol ones).
Photovoltaic cells are pretty powerful is direct sun (100mA at 4.8V is common for film type one) so you could create a free energy top-up service on your wings.
Autopilots are now more accurate, more stable and with more options.
Airframe design has shown efficiency with the soaring community.

Mix this together (with lots of testing and planning), its not unfeasible to imagine a pretty kick ass plane.

A small gas engine for power with a large fuel tank (probably custom), a LiPo battery for powering the electronics with a LiPo charger circuit connected to a bank of solar cells on the wings providing 1A@4.8V to top-up the battery. As long as you have enough fuel it should stay up. If you limit throttle for climbing from 400ft to 4000ft then gliding back down whilst following the waypoint path you could save even more fuel (I'd presume).

Hope this gives you an idea

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Comments

Trent at MyGeekShow July 3, 2011 at 11:28am

Ritchie: I haven't entirely given up on the single flight idea... I'm open to options and know that as I progress toward my goal things may change. You're right though, technology in this area has totally changed over the last few years, and one can hope that it will even get better.
Paul Mather July 1, 2011 at 3:49pm

I don't know what happened. The website says they're on pilot #287 and it's been 1132 days....that's almost 4 days per pilot. After a year I think I would have said "well, we tried." Or maybe name it after a decade instead of a year...so WAA '10's.
Ritchie July 1, 2011 at 3:15pm

Yes I know Happy I was just giving the idea of a single flight some imaginative oomph. Shouldn't WAA have finished in a few days even if they just drove the damn thing? Are they photomapping the US or something extra or just very slow :S
Paul Mather July 1, 2011 at 12:33pm

I don't think he was proposing doing this in a single LiPo.... as that level of complexity is probably out of the scope of this project. He's trying to do in a week what Wings Across America '08 hasn't done in three years. Granted, their goal was to get multiple pilots involved...but so far, each pilot has been averaging 4 days in posession of the plane. One guy, one plane, a BUNCH of LiPo's....should be doable....
Ritchie July 1, 2011 at 6:32am
I had a thought this morning about your 5 year plan. Flying across the US is much the same feat as flying across the Atlantic like the great Maynard Hill accomplished. Perhaps you could do this on the anniveersary of the launch for TAM as a tribute.

The TAM flight took 1883miles to cross the Atlantic with less than 1 gallon of fuel. With many accessories being run from the engine system too dragging the efficiency down. Your US flight will need to cover approximately 2500 miles. The TAM flight was a huge challenge but a US flight is a gargantuan challenge so everything must be at its best which is where I started thinking.

The TAM flight was complete on August 10 2003, we have had 8 more years of advances since then to aid you effort.
- Engines are smaller, more powerful, more efficient with a raft of tuning options to help get everything right for the seasoned tinkerer (I mean petrol ones).
- Photovoltaic cells are pretty powerful is direct sun (100mA at 4.8V is common for film type one) so you could create a free energy top-up service on your wings.
- Autopilots are now more accurate, more stable and with more options.
- Airframe design has shown efficiency with the soaring community.
Mix this together (with lots of testing and planning), its not unfeasible to imagine a pretty kick ass plane.

A small gas engine for power with a large fuel tank (probably custom), a LiPo battery for powering the electronics with a LiPo charger circuit connected to a bank of solar cells on the wings providing 1A@4.8V to top-up the battery. As long as you have enough fuel it should stay up. If you limit throttle for climbing from 400ft to 4000ft then gliding back down whilst following the waypoint path you could save even more fuel (I'd presume).

Hope this gives you an idea
Trent at MyGeekShow June 29, 2011 at 4:48am

Great tips John C. I'll have to add these to my pre-flight checklist.
Trent at MyGeekShow June 29, 2011 at 4:47am

Thank you for the encouragement! I'll admit, It was a little frustrating to see my work destroyed because of simple user error... I do feel a little better knowing I'm not the only one to have done it though :)
Matthew Tang June 27, 2011 at 12:00pm

Done that before.
Kirill June 27, 2011 at 1:42am

Trent, I enjoyed watching your video, it's very well done! You're definitely have producer skills. :)
Don't give up and continue the work, actually you have already got all needed advice, so I believe, you will achieve success!
Moderator

Alex June 26, 2011 at 12:52am

@ Trent I too find your videos entertaining and I think its great that you show your success and failures as it is the best way for both your viewers and yourself to learn from comments people give about the problems you are having. All the best for your project!

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