Flight Test Log 2
The SVC and PAD were flown several times. Main results:
1. For the SVC, sustained flight at a very high angle of attack (> 30 deg)
is possible at high throttle settings. In this mode the airspeed is very
low and the vehicle descends at a slow rate. At least rudimentary steering
This mode could be useful for autonomous landings, which is worth 200 points
in Level 3 of the IARC competition. If the mode can be refined and automated,
it would avoid the additional weight and complexity of a parachute, which was
what the UA team attempted at the 2004 competition.
2. It is easy to repair the subscale SVC, which uses a very simple structure.
The main wing consists of a mostly flat sheet of 12 mm thick styrofoam,
uncoated, with minimal shaping at the leading and trailing edges. After two
major crashes, most repair consisted of gluing pieces of foam back together,
followed by lightweight spackling compound to fill in small dings.
Also, the upper fuselage consists of three components that are attached by
masking tape. The tape is strong enough to carry in-flight loads but weak
enough to separate in a crash. The result is that the upper fuselage
components tend to break free in a crash and are usually undamaged.
Downtime has been minimal. In the most serious crash, which damaged the nose
section (see below), repair labor took less than 1 hour and the airplane
was flying again the next morning.
(Note that these repair issues refer to the subscale version of the vehicle,
which is similar to a rapid prototyping version. Repairs to the full scale
vehicle depend on the exact type of structure and materials used. Composite
materials would no doubt require substantially different repair techniques.)
3. One flight accidentally ended in something like a carrier landing. I
goofed a landing approach and flew too low over a fence. The receiver
antenna snagged the top fence railing and decelerated the vehicle to a
full stop, with basically no damage.
Most of the energy was absorbed by the antenna and boattail pulling loose,
and the vehicle was left dangling by the antenna, with the nose suspended
a few inches above the ground. Aside from masking tape pulled loose, there
was no damage. The antenna was attached to the boattail, which prevented
stress from reaching the receiver.
Possibly a variation of this mode, with purpose-designed arresting gear,
could be combined with the high-alpha mode as part of an autonomous landing
Test ID: 8
Scale: 41 %
Too windy, vehicle was difficult to control, crashed into garage roof (was
flying in back yard). Nose broken in several places, gearbox destroyed,
Repair labor 37 min. Powerplant replaced, battery salvaged.
Nose damage and repair.
Test ID: 9
Scale: 41 %
The SVC flew well, was controllable. Elevator control is OK, but it would be
better if there was more up elevator control when power is off. There is
plenty of up elevator control with power on.
Attempted slope soaring as an exercise in controllability. The pilot had no
previous experience with slope soaring, and pilot error on landing resulted
in an accidental carrier landing on the back porch fence.
The vehicle itself cleared the fence (barely) but the receiver antenna
snagged the top fence rail, and the effect was similar to a tailhook
landing. The antenna and boattail absorbed the shock, and the SVC was
suspended, nose down, several cm above the ground. There was no apparent
damage other than tape pulled loose.
Tried high-alpha flight at full power. Seems to be somewhat stable, very slow.
Hit tree on landing approach, took chunk out of left wing LE, just inboard
of snag. Wing was also cracked.
Repair labor 30 min (approx).
Left wing damage and repair.
Test ID: 10
Scale: 41 %
Installed new Cirrus Micro Joule flight pack in PAD. Battery is Duracell
PX28LB, 6.0 VDC, lithium primary, 10 g. Only rudder servo was installed,
other 3 servos didn't work -- need to be exchanged.
Flew several flights, rudder only. Flew OK, control indeterminate because
of lack of roll control.
On last flight, broke off left canard, repair took 20 min.
Hinge allows fuselage
to open up for access
to internal electronics.
on upper canard.
CS-3 servo is 2.9 g.
Last updated 2004/11/14 FLM