First Customer HELICYCLE(c) Flies
Doug Schwochert of Burlington, Wisconsin installed a
turbine engine in his HELICYCLE and made it to first place in the
HELICYCLE Customer Flight Line-up. This was no easy task; Doug not
only had to design the engine mounting system, he had to build a gear
box to reverse the direction of the engine output shaft. His modifications
worked flawlessly. At the end of the fourth day of his factory check
out, Doug was performing high speed, low altitude quick stops and
had made several circuits at altitude around the Burlington airport.
Eagle R & D, headed up by B. J. Schramm who started
the RotorWay kit helicopter program in the late sixties, is taking
a very different approach to customer service this time around. Instead
of letting its customers go it on their own after the construction
phase, they are sticking very close until each customer has been safely
guided through the transition to final checkout and fully operational
flight. The checkout program is conducted either at the builders premises
or at the factory. It takes place after the helicopter is completed
and has received its airworthiness certificate. The builder must have
soloed in an R-22 or have recent time as P.I. C. In an R-22. During
the RotorWay days, a builder could get his ship off the ground in
several "unauthorized" ways and the result was a very high
roll-over rate, over which the factory had no control. There were
few injuries, however a whole lot of painstakingly crafted parts were
turned into instant junk. Interested parties looking on, were immediately
turned off. To prevent this carnage in the HELICYCLE program, key
components are withheld and installed by the factory test pilot at
the start of the check out. This policy also prevents 2nd owners from
purchasing a partially completed HELICYCLE and wreaking havoc with
it.
The factory checkout takes approximately a week and
consists of the following:
1. A very thorough mechanical conformity and
construction checkout using an itemized check list and special factory
tooling.
2. A rigging inspection of all controls & rotor system
components.
3. A physical weight and balance hang test to insure that the
c.g. is absolutely correct for the very first lift off.
4. The main and tail rotor systems are final dynamically balanced
and readied for flight.
5. Power plant break-in procedures are completed.
6. The factory test pilot performs a comprehensive series of
flight tests including power off autorotations to insure correct adjustment
of all controls and flight surfaces prior to customer operation.
7. The customer is briefed on pre-flight checks and begins
the first tethered lift off's.
8. Following a brief period on the tether bar, the customer
lifts into his first free flight hover and continues to gain confidence
in his ability by performing in-ground effect maneuvers under the
test pilot's watchful supervision. Hovering the HELICYCLE is quite
easy for anyone with some training in the R-22. (Doug Schwochert needed
less than one hour of time in a hover before beginning excursions
through translational lift.
9. Flight into and out of translational lift is practiced until
the customer has successfully completed accelerations and decelerations
(Low altitude, high angle quick stops) through incrementally increasing
airspeeds up to 50 - 55 mph. Doug was able to complete this phase
in approximately and hour and a half. When a helicopter pilot can
capably perform a 55 mph high angle quick stop, he can also adequately
perform the flare maneuver at the end of an autorotation, so the factory
check out is not completed with out the test pilot's confirmation
that the customer understands and is becoming proficient in this highly
important maneuver.
10. Climb out to altitude and very soon to follow autrotative
entries may begin to be practiced by the customer during the check
out (providing his skill allows him to do so). If not, he will continue
with this practice on his own and report his progress to the factory
pilot who will consult with him as he proceeds. (Doug was able to
safely begin climbing out to altitude during the check out.)
INTERESTING ASPECTS OF DOUG'S CHECK OUT
The single shaft spool Solar turbine installed in Doug's HELICYCLE
presented some pretty serious and challenging considerations for the
factory test pilot, in this case the HELICYCLE's designer, B.J. Schramm.
A turbine engine in a conventional commercial helicopter has two spools.
The gas generator and a separate power turbine which is geared to
the helicopters transmission. This feature allows the geared power
turbine to instantly respond to all throttle conditions demanded by
whatever flight condition the pilot initiates. A directly geared single
shaft turbine has a lag in response time. This could turn into a very
critical problem for an experienced test pilot, much less a low time
customer pilot. B.J. conceived a flight test plan of incremental steps
which allowed him to proof the electronic fuel control & turbine
spool up response time without endangering his life or taking the
chance of seriously damaging the machine. The results of these tests
proved very encouraging and their successful completion allowed Doug
to proceed without fear of consequence right on through his accel
& decel learning phase. It should be pointed out that the chances
of success with this single spool turbine were seriously in doubt
prior to this check out. Both B.J. and Doug were not overly optimistic
about the outcome. The fact that this installation will tolerate throttle
chops and severe angle deceleration quick stops bodes well for the
future.
The life of a test pilot is said to consist of hours
and hours of boredom and moments of sheer terror. Doug found this
to be true on his checkout. B.J. had commented on the eventual necessity
of a fairing to smooth out the air flow on the underside of the ship
between the fuel tanks and the front of the engine. It was thought
that this would not be a problem in slow flight. WRONG ! !
During a down wind descent, Doug encountered what felt
to him like a serious dynamic imbalance in the main rotor. He continued
his descent and pulled into a hover at which time the condition disappeared.
Needless to say, the fairing was installed immediately and the problem
was not encountered again. Doug decided then and there you couldn't
put any price on the factory check out.
The risks he would have subjected himself to in attempting to flight
test an unknown turbine engine installation became pretty obvious
after this incident.
The excitement was not over yet however. An unusual
hum, (very low) seemed to make itself apparent in the cockpit. Doug
was by now kind of on pins and needles. Doug felt the noise was from
the transmission and B.J. agreed that it could possibly be that the
upper lift bearing in the transmission might not be getting oiled
properly. This was very doubtful, however Doug deserved
confidence, so B.J. suggested that they remove the transmission and
disassemble it. Of course this meant almost complete disassembly and
reassembly of the entire machine. The time for this process was estimated
at 11/2 days. The good news is that it was completed in just 8 hours
and Doug got to see that everything inside the transmission was absolutely
perfect including oil to the top bearing. Guess what, Doug and B.J.
stopped hearing things (turbines do whine a lot) and Doug began to
make great progress with his accel and decel training.
WHAT'S LEFT TO DO?
Doug's HELICYCLE isn't quite finished yet. When he purchased a 180
lb. Engine, he knew it would way over gross the ship. It's not a matter
of whether or not the HELICYCLE rotor will lift the extra weight.
The problem is that the fatigue loads to which the individual parts
were designed will be violated. It is then unknown how long they will
last. Doug has in mind to reduce the engine weight by 40 to 50 lbs,
by re-designing the drive section end of the power plant. This engine
is a ground power unit and has all sorts of pads and heavy castings
which are not necessary for the helicopter installation. Doug plans
to get underway with this effort before he logs much more time on
his airframe.
AN INTERVIEW WITH DOUG
1. Was he happy with the overall outcome of the
check out?
Ans.: Yes, the check out was much more in depth than
I had ever thought it would be.
2. Is he convinced of the need for it & why?
Ans.: the check out is definitely necessary. I would
not even dream of Trying to begin operating the ship without factory
assistance.
3. Describe some of the new things he learned.
Ans.: A. The airflow problems with the turbine would
have taken much longer to sort out by myself.
B. I was surprised at the smoothness. There was no cyclic stick shake
and the rotor can be adjusted to extreme smoothness in hover and forward
flight.
C. The rotor is very efficient. The extra weight of the turbine hardly
effected the collective pitch on the blades.
4. How does he feel about the way the HELICYCLE
flies?
Ans.: "The ship is so easy to fly, I got up to
75 mph on my first climb out without even trying. It will be really
easy to cruise at 95 mph".
5. What will he be using his ship for.
Ans.: Mostly local pleasure flights for now, but I do
plan to do some serious cross country flying down the road.
6. How does he plan to improve the ship in the future?
Ans.:
