Basic Configuration for a "Safe" airplane

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challenger_II

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If you are discussing the AA1, changing from the O-235C to an O-290, or an O-320, the weight of the engine package is a wash: mostly in the oil cooler, and propeller. Replacing the nose gear strut does add a tad bit of weight.

I don't know how much actual weight increase we're talking about. Re-engineered in such a way, I would expect more power would be part of the picture. There's quite a few out there with an O-320, and added fuel capacity is an available STC as well. Both add weight, but the owners don't seem to mind. I wonder if just the airbags or just the safety cage, with a larger engine would be a solid performer. If you look at the power loading, it's better than contemporary two seat trainers like the Tomahawk and Skipper. The wing loading is higher for the AA1.
 

Rataplan

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That is the key to this discussion. Would it still be fun with some of the posited safety mods such as interconnected controls, limited elevator travel, added weight from additional cockpit structure and air bags?


BJC
Beside how would that semi automatism help recover from strange attitudes? imho the main thing is training. and staying aware of things. all planes have their own character.
 

Pops

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My Falconar F-12 stalled at about 68 mph, no stall warning other than a high deck angle and lower noise level, and the next split second you were looking almost straight down and would spin right or left even with a small crosswind. Easy in and easy out. Spun it a lot. Very predictable in stopping the spin. In landing I could get it down to 80 mph if light weight with just me, with a passenger I used 85 mph before getting into a high sink rate. Used 100 mph in the turns in the pattern and shallow banks.
 

speedracer

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In the 1940s and '50s and '60s an huge number of people learned to fly, many of them in taildragging spin-prone airplanes like Champs and Cubs and Cessna 120s and lots of other that we seldom see today. Most of those people didn't kill themselves. They died in bed like most other people. And they had no GPS, ADF or VOR, either, but managed to fly long distances using the magnetic compass, a watch and a map. All of this required a lot of learning and study. The human brain hasn't gotten smaller; it's gotten lazier as machinery has taken over and spoiled us all. That laziness has led people to believe that learning to fly is too hard, that we need safer airplanes to make up for the lack of knowledge. The safer airplane is nice but is no substitute for knowledge. The old saying: "You make an idiot-proof device and the world just comes up with better idiots."


I tried to stall a Tri-Pacer. It would not stall at idle or at full power or anywhere in between. There were two of us in it; maybe with weight in the back it would have stalled. I also didn't try running the trim full-up, which gives the stabilizer more down-lift. Jackscrew type stab. Maybe it would have stalled if I had skidded a descending turn in it, but its reluctance in straight-ahead flight makes me think it would resist that, too.
Now, people go learn to fly in an airplane like that and get used to skidding, then they go fly a Champ and it kills them. That's the problem with idiot-proof stuff. It creates idiots that should be confined to the idiot-proof stuff. Training in airplanes that will stall and spin is much better. It becomes much more than a hazy academic idea at that point.
I did that also in my first airplane, a $7,500.00 Piper Colt. I had taken some acro lessons in a Citabria and wanted to spin it. Full aft stick it would just mush. But... if I lowered the nose, picked up speed , then went full aft stick it would stall just fine. I spun the heck out of that little airplane.
 

speedracer

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When I took my first biannual flight review (at 48 years old) my 18 year old guy was doing HIS first flight review. We took off runway 25 at Hood River, OR. About 200 yards from the departure end is a restaurant with outside seating. As soon as we broke ground he says "Lemme have it" and he buzzed the restaurant. He had me demonstrate some stalls. After a couple and just before another broke he says "lemme have it" and kicked it into a spin and said "your airplane". Thanks to my (two) acro lessons in a Citabria I kicked it right out. He told me he was impressed, not knowing about that training. He was a genuine hot dog and got fired after three weeks.
 

TFF

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The real stinker when I did my friend’s 320 conversion on his AA1B was the prop. 19 lb McCauley got replaced with a 34 lb Sensenitch. 5 lb added to the tail. The 320 engine is heavier , but at its station it wasn’t hurting as much as the prop. His already had the oil cooler and nose gear. He is in the market for a reasonable priced DER. He owns the intellectual rights to one of the extended range tanks STCs, but having FAA problems. They would like to produce a run if they can get a new PMA established. The 22 gallons of fuel does not go very far.
 

Bigshu

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5 lb added to the tail. The 320 engine is heavier , but at its station it wasn’t hurting as much as the prop. His already had the oil cooler and nose gear.
Yikes, 15 lbs of prop, and 5lb of dead weight in the tail, beefier nose gear and an O-320. He must fly alone, and not for very long.
 

Pops

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Neighbor used to own a AA-1 with the 150 hp lyc. I didn't care for it, lot better airplanes out there.
 

Dan Thomas

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Yikes, 15 lbs of prop, and 5lb of dead weight in the tail, beefier nose gear and an O-320. He must fly alone, and not for very long.
There are many airplanes that should be left alone. Adding power means adding weight, sometimes lots of it, and in a short-winged affair that's asking for trouble. Take all that money and buy the airplane that will do the job without all the compromises.

My Jodel D11 stalled at around 40 MPH. A-65 engine. Pops' F-11 with its O-320 stalled at 68. Those short wings really don't like increased weight. When I was alone it flew OK. With another person it glided like a sack of rocks and climbed rather leisurely.
 

Pops

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Not a F-11. Its a F-12, the 12 is built for up to a 180 hp Lyc. I built the engine from parts and believed it put or about 160+ HP. Looked at my records a few weeks ago and the EW was 1050 lbs, I was thinking it was lighter. Single place the ROC was 2200 fpm. GW of 1800 lbs with a ROC of 1700 FPM. Sen 74x56" prop it would turn 2900 rpm at 3k at WOT. Cruise at 2450 rpm at 150 mph. VNE at 187mph and lower the nose just a little and airspeed would go up quickly. Got it at 200 mph true one day by not paying attention.
Keeping the ROC down like most GA airplanes, I would have a climb speed of about 110 mph.
 

Bigshu

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If you don't like an Ercoupe the right answer is a Facetmobile.
Maybe, no performance numbers to judge. If it's one or two seats, probably won't have the useful load I'm looking for.
 

Vigilant1

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I like it but this topic is about safe aircraft configuration. Motorgliders can be very efficient but do not have any especially safe characteristics. Ercoupe or Facetmobile are the choices.
Safe/unsafe is not a binary situation. There are just relative (and subjective) degrees of safety. A motorglider with relatively low stall speed, good handling qualities, and (notably) a good glide ratio may provide a choice of safe landing options unavailable to planes of more limited glide capability. That's worth something.
 

cluttonfred

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True enough, though some sort of spolier(s) or air brake(s) also become an issue in that case so you can stop flying when you need to.

Safe/unsafe is not a binary situation. There are just relative (and subjective) degrees of safety. A motorglider with relatively low stall speed, good handling qualities, and (notably) a good glide ratio may provide a choice of safe landing options unavailable to planes of more limited glide capability. That's worth something.
 
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