First Flight(?)

12 July 2003 - Ready for flight trials.

I took it down to the local grassy field at the park, figuring there's lots of room, realtively few people and things to run into (no big trees, for instance). Here's a few shots of the general operation. All photos (most taken by Samantha Lux) are thumbnails and click to open in a new window.

Unfolding the chute/wing	Started up just fine	Give it some throttle.. Note the brick in the foreground to tie it down to. Big mistake.

Gave some throttle and it starts to run. There's also a fair amount of friction from rolling through the grass, though, as you pick up speed, the wheels start to lift off, and it really accelerates. You start walking along side as it runs.

Here's a shot as it starts to get rolling, and the wing starts to pick up. Note, however, that the wing isn't centered over the trike.. it's off to the left a bit. There's a bit of wind, and from a direction different than I had lined up the trike.

The off angle force from the wind causes all sorts of problems. For one, until you're flying, you don't really have much directional control, so you wind up getting snagged in things like trees (as well as trash cans, tools you've left lying on the grass, softball backstops, etc.).

Fortunately, quickly shutting down the engine (I wound up doing that a lot), and disentangling isn't too hard.

In the two pictures below, you can see a wheel starting to lift, or in one case, flipping over backwards.

Unfortunately, the CG is pretty high on this thing (it's really designed so that the thrust line is right at the spreader bar, and since the engine is the big weight (particularly with an empty tank..), this is what happens next.

I learned that a better fuel tank vent strategy is called for, since in this inverted position, the fuel slowly drips (gushes?) out the vent tube. For what it's worth, gasoline also dissolves the glue in double stick tape, so the ignition module comes loose.

I also discovered, on the last crash, that the structural approach for the prop guard isn't really suited to this kind of abuse. The guard deflected enough that the support encountered the prop, shortening the prop and neatly severing the supporting tube (and, incidentally, launching small pieces of metal at high speed):

The side support tube also fractured neatly at the screw holding it to the engine mount plate. Clearly, a more sturdy design is called for, at least with a rookie pilot.

Here's some more close up photos of the trike, and related equipment:

Here's the engine running, you can see the (3) control lines going through their gude and trailing back, under the cluster of main support shrouds (which, in this view, seem to be tangled together.	Here's the receiver, and a good shot of one of the servos and it's control arm. The forward battery is going to the radio receiver, the aft battery is for the electronic ignition, which is the small silver box, upper right, with a thick black cable going to the spark plug.	Here's a good view of the two steering servos. This position also indicates why it's important to have a more sturdy prop guard, because the wind will nicely pull the trike over when the sail inflates.

And, yes, everything fits conveniently into the back of the car for the ride back home.

robots/ppc/firstflight.htm - 13 July 2003, Jim Lux
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Copyright 2003, Jim Lux