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.: A. I haven't completed the doors yet which are necessary for 95 mph cruise.
B. I will be adding an electric actuator clutch so no helper is needed to bring the rotor up to rpm after engine start.
C. I will modify the turbine gear box to reduce weight, hopefully around 40 lbs.
D. I would not change anything about the design of the ship. It flies just perfectly.
7. How does he feel about the cost effectiveness of his choice in purchasing the HELICYCLE over other designs?
Ans.: I didn't look at the price comparison between the HELICYCLE and other ships nearly as much as I did the experience and design history behind the helicopter. If there were a less expensive equivalent on the market it wouldn't have made any difference to me.
8. How has he found the factory support and customer service?
Ans.: I really didn't need much help during construction, the video tapes covered pretty much everything I needed to know. The check out is another matter, I would have hated to do without it. What we did in just a few days would have taken a month on my own. In addition, I feel my safety was much enhanced by having a factory pilot demonstrate how the ship would respond in each maneuver and flight condition before I tried it.
Doug's first circuit around Burlington Airport.
Doug preparing to climb out.
The turbine installation is quite simple and its as smooth as an electric motor.
The HELICYCLE just about fits under the "A" Stars tail boom.
This photo shows Doug in the flare at the end of a 35 mph quick stop. The flare angle is increased in increments with additional air speed, until power is reduced to zero. This condition is achieved at approximately 55 mph. When the ship is leveled after the flare, it will be at near zero forward speed & at an approximate 3 ft. skid height. Power can be rolled off and the touch down cushioned with collective. This maneuver exactly simulates the end of a power off autorotation. When it is performed correctly, the pilot is ready to safely climb out to altitude.
Doug preparing to climb out.
Doug using the tether bar on his first few lift offs. The bar is secured at each end with an 8" - 10" length of chain.
Doug kneeling next to his pride & joy. Doug has come a very long way to get to this point. He built a bare bones kit helicopter design from scratch and learned to fly it enough to really scare himself. He earned his helicopter ticket in an R-22 and he now has his own turbine powered "hot rod."