Lucked out with minimal damage.........

I was flying with Mike Condon at the AMA site yesterday when all of the sudden, in the second corner of an outside square loop my airplane slammed into the blacktop. I had finished the pattern and was doing two outside squares to unwind my lines when it happened. The airplane (Muncie Heat) had made the second corner of the second outside square and was inverted and about 4 feet high when the wings rocked and the airplane went in, breaking off the rudder and then skipping off of the blacktop and back into the air. Amazingly when the airplane bounced into the air the engine was still running, with a prop that had about an inch broken off of one tip and about an inch and a half broken off the other. The airplane continued around the circle inverted with enough airspeed for me to get it up high enough to tuck it under. After I got it upright the engine was really screaming and the plane was shaking violently so I decided to try an inside loop to hopefully kill the motor. The loop worked and the engine stopped. I brought it in for a landing and then made the long walk from the center of the circle to inspect the damages. I picked up the airplane and Mike and I began the assessment but to our amazement the only damage was the broken off vertical fin and the broken prop. Everything else including the engine seemed to be fine. Mike and I made a quick field repair to the vertical fin and I changed the prop and within fifteen minutes I was back in the air and the airplane was flying as good as ever.

I have been flying this airplane for three years now and have never had the model stall in a corner. Mike thinks I got caught in my own prop wash because it was pretty much dead calm during my flight but I have no idea what happened. I know I got real lucky but I wish I had the whole thing on videotape because it sounds like a big fish story. What happened ? Any ideas? Your input would be greatly appreciated.

Thanks in advance,

You are probably correct. If it was dead calm, you probably got hit by your own prop wash.

I know some of the top flyers unwind their lines before they land, and they usually do something more "spectacular" like outside triangles or some such (you were doing outside squares). I have always suggested against this, however, as something bad could happen and cause you to lose pattern points and the landing (not to mention the plane should you suddenly run out of fuel at that point). I realize you were practicing and in this case it was rudder damage and a prop was all you lost, but it would have DQ'd you had it been an official flight.

That said, when the wind goes calm, learn to back up, open up the maneuvers a little more (to give more time for the air to dissiplate), and fly a little higher just to avoid the slam dunk.

I agree with you and Len's assessment. And you WERE very lucky!
I think everyone has experienced this on a dead calm day whether we knew it or not, and maybe with out the crash.
I really don't like flying on calm days.
Bill

RICK...One thing I would do is open up the bottom and check the bell crank. No harm, No foul. When this happened to me I was glad to do it. I found the bell crank post had come lose.

Scott(hate to cut open a friend)Riese

> Mike thinks I
>got caught in my own prop wash because it was pretty much
>dead calm during my flight but I have no idea what happened.
> I know I got real lucky but I wish I had the whole thing on
>videotape because it sounds like a big fish story. What
>happened ? Any ideas? Your input would be greatly
>appreciated.

Classic dead-air crash. As you get better, this will become more and more of a problem. Other than carefully stepping back, not much you can do about it in the real maneuvers. However, if you are just unwinding the lines after the end, it makes sense to either do two different maneuvers (like a square and a round), or intentionally make the second one in a noticably different place from the first - like, extend the top of the second outside square so you are flying through clean air at the bottom of the second one.

This has happened to me on three occasions before I wised up. Most of my stupid wrecks come after doing my "pattern" and run out of fuel or hit my own turbulence. Now I just fly level until the engine quits and try to land without embarassing myself. Lately I have been going home with the same number of planes I arrived with. I now, always, unravel the lines after landing. Hey, I am getting better.

Rick,

It's a good thing that you didn't hit your wake after the first corner of the second loop when the plane was pointed straight down! I did it about two weeks before the 02 Nats. The plane ended up buried up to the wing root in John Simpsons grass taxiway flying site. On a pavement surface like you were on it would have pulverized it into small splinters clear to the Rudder! When in dead air I get really nervous, but my intrepid handles the turbulence much better than the Magnum did (Different wingtips).

I've bounced in twice in dead air, both times on the second triangle just after making the turn to level. No major damage either time. One really has to pay attention flying in calm air, and move back, or forward, with each repeated maneuver.

Same thing happened to me on circle three at Muncie in the Team Trials two years ago. It happened in the outside squares and took off the rudder, canopy and prop. Put it back together and flew the rest of the Trials and the Chicago contest the next day.

When flying on calm air days, I begin a manuever just downwind of the pilot's circle and walk backwards at a steady rate until the manuever is done and I finish on the upwind side of the circle. Of course I recommend to get back to the center of the circle after the maneuver immediately.

The same thing happened to me this afternoon at Ned Brown in Schaumburg - burble in the 2nd inside loop - almost dumped the Legacy out of the circle. It was calm and I just let it go inverted/level out of the loop until things settled down. The technique of stepping backwards worked later on - when I could remember to do it.

Joe

Joe Owen

Thanks for all the information guys. I stripped the Monokote off of the vertical fin, sanded it and recovered it last night after work. I hope to fly this weekend and if its calm I plan to try the step-back method so many of you described.

Thanks Again

Hey guys, Great information! I have only rarely experienced dead calm air. The only time I can remember was back in the '70s in Springfield, MO. In Pampa, TX this is NOT an issue.

It's quite impressive what your wake can do. I've bumped the edges of it plenty of times, a little rocking of the wings being the only result. But I've hit it square on in dead air and it can really send your plane for a loop. Generally though, with at least 5 mph wind, it seems to drift away pretty well, not that I've ever been in Texas with the wind under 15mph, so you're pretty safe. Heck, I lived in Wichita for a year and a half I think the wind only layed down 2 days of it. The rest of the time it was either a blast furnace or a deep freeze.

One of the ways we used to confirm that a loop was well done back when I was flying full scale aerobatics was hitting the bump of your own wake coming down the back side.

I remember once when I was being checked out as an instructor at an aerobatic flight school in a Decathlon. It was a fine picture perfect day and a bit of unspoken competition was on between me and the check pilot.

He took the Decathlon up to altitude, lined up on a road dived for entry airspeed and lofted us up over the top. Just coming down the back side with the nose coming up to the horizon there was a solid jolt as we flew through our own wake. When he was finished, we were at the same altitude, airspeed and orientation as when the figure commenced.

Now it was my turn and the implications were clear: "Match That!"

I went through the same drill and flew the most precise loop I possibly could.

There was never a more satisfying bit of turbulence in my career than the bump we felt as the plane concluded that loop.

This is interesting. I made a lawn dart out of my AASr the other day while flying in dead calm weather. It didn't come out of a large inside loop and went into the ground with total destruction. It didn't respond to control input and the lines were tight. I thought the controls locked up, maybe not. In a prior flight I noticed it bobbled while doing a loop and was sure it hit flight wake but didn't consider it harmful enough to bite.