Losing the training wheel.

[Bryan Cotton]

My first inverted spin was inadvertent. We were doing Immelmanns and mine were rushed and sloppy. He wanted me to pause at the top and make sure I was level inverted before I rolled out. So I paused, looked left and right, and I was nice and level. I had managed to stop with my nose up a few degrees though and my airspeed continued to drop off until it stalled inverted. With full power on, it went into a spin. Tom said "this is an inverted spin." For those of low skill like me, both inverted and upright spins look the same - straight down, even though they are not. I said "this is an inverted spin?" Tom's reply was "yes, and now it's a full blown one." None of my recovery tactics were working, and Tom said "you will never recover if you don't pull the power off." I did as he instructed, but more thrashing about did not improve things. "Look for the heavy pedal." On the ground Tom had told me that upright or inverted, the rudder tended to trail in the direction of the spin, and an anti-spin input would take more force. I switched feet (having been previously convinced I knew which way we were spinning), the pedal forces went up, and out we popped into an inverted stall. My overwhelmed, positive G brain knew we were stalled but muscle memory had me pushing forward to break the stall, which of course held us nicely in it. "I got it." He recovered after talking me through my attempts, a 4000' altitude loss with a recovery at 2000' AGL. "Next time out we will do inverted spins." On that next time out, we did a lot of gentle entries from a straight ahead inverted stall. The last one we entered upright at 80, stick full forward and full pedal. That is the most violent thing I have ever done in the air. I held it in for 3 turns, it never settled down but it did pop right out when I wanted it to.
I miss the good old days sometimes.

[rizzz]

I've been taught basic aerobatics (wing-overs's, loops, rolls, etc.) incl. spin recovery off course, I did this in a Citabria.
Now, most of the time I go flying in the Citabria I'll do at least some aerobatics (unless I have a passenger in the back who objects, and/or I'm too heavy at that point).

I haven't done any inverted spins though. I remember falling out of a loop once but ended up in what I believe was a normal spin.
Can you get an aircraft like a Citabria into an inverted spin? Can a Sonex be put into an inverted spin?

Before my first flight (which will hopefully happen this year) I was planning to go back to my instructor for a couple of weeks of "intense" training, specifically with the eye on flying an airplane for the first time, preparing me for anything that could go wrong.
I am planning to include aerobatics in my phase 1 testing as I will be flipping my Sonex around from time to time, so should I get my instructor to take me through some inverted spins as well before doing so?

[Bryan Cotton]

You can do an inverted spin in anything, in theory. Most inverted spins in the Pitts were a result of me screwing something up, like the Immelmann or vertical rolls were really hard for me. Airplanes without inverted systems will not be happy, because you are inverted! If the instructor is comfortable with something, I would experience it all except for low level. That is just me, I prefer the insurance of altitude. Leave the low stuff to Sean Tucker and those folks.

[fastj22]

My introduction to the inverted spin was an intentional failed loop. We brought the Decathlon halfway through the loop then pushed the stick forward to arrest the decent back through. -2G. The wing stalled and we went into a violent spin. Recovery was the same as a normal spin, but the disorientation was greater and my hat flew off. Hanging from the harness inverted at -2G then going zero G as the earth just spun under us took me awhile to figure which rudder input to make. Once I arrested the rotation, we where going straight down and accelerating fast. A 4G pullout back to level and all was well again. 2000ft loss. 15 seconds tops but the world went into slow motion for me.

[fastj22]

I did a preliminary W/B yesterday, and am surprised how much weight I lost. I call it preliminary because I didn't weigh both mains, just assuming the same on the other and the engine didn't have any oil in it. Leg fairings and pants also not included.
285lbs on the left main and 57lbs on the tail.

My tri gear Waiex came it at 706lbs. The new weight came in at 627lbs. New configuration has Tracy Obrien gear legs and brakes. Old configuration was stock sonex solid titanium legs and Great Plains disc brakes, pants and leggings. Perhaps that is the majority of the savings. I'll try to weigh all the stuff I took off. I should have weighed all the stuff I put on too, lost opportunity.

If this weight is accurate, my suspicions on being tail heavy are confirmed. I'm well within the aerobatic box solo with a full tank of gas, but at the back edge with half a tank. I also approach the back side of the utility category with two passengers and baggage.

I may end up swapping my super light lithium battery with the lead acid Odyssey and see if I can move CG a bit further forward. I don't really want to, the lithium has served me well.

[Bryan Cotton]

I would be very interested in the weight of the old vs the new parts.

[MichaelFarley56]

Very cool! I'll be interested in seeing what your final weight ends up being. My basic, polished, AeroVee Waiex came in at 644 lbs and I've never heard of one weighing less than that. I think the factory prototype is 670 lbs; most VW versions are around 650-670, and it seems the Jab 3300 ones are slightly more.

Keep us up to date on how things are going! Are you almost done with the rebuild? Hopefully the cowling work is coming along...

[fastj22]

I'm pleasantly skeptical about the new weight. For my original weight, I used a friends scale. For this one, I purchased a 400lb postal digital scale. So that is a variable. It reads my 200lbs body just fine. I may borrow his again to verify. I need to find a 280lb person to verify it! Or me holding an 80lb bag of cement.

The T Obrien legs are definitely less weight than the solid titanium. The brakes are also lighter and smaller than the Great planes.
I built my plane as light as possible with no frills except my dual xTremes, paint and interior.

As for the cowl, after cutting the holes for the legs, it almost fits. The thrust line is a bit higher and I need to trim the top edge to get the prop hole centered again. The prop flange is 1/8 forward from the other mount also.

[Bryan Cotton]

I have not looked at W&B yet. What is the a Sonex datum? Are the TOB wheels in a slightly different spot?

[fastj22]

The TOB legs are slightly longer. I need to measure the datum point before getting an accurate balance.
There are a couple of good excel spreadsheets on the Yahoo forum.