Flight News On New Helicopter R66 Turbine Engine & Hlicopter Safaris

What an experience this turned out to be for me. Waiting for me when I arrived at the Torrance factory were Michelle Cantu and Dou Tompkins, the Robinson Helicopter Corporations chief pilot who was to be my mentor.

With all the relevant paperwork and indemnities completed, I was given a full comprehensive technical run-down on the new helicopter .It consisted of an in-depth briefing on the airframe, engine, mass and balance and normal and emergency procedures.

On completion of the classroom lectures, we proceed to the helicopter where Doug Tompkins went through the pre-flight with me focusing on the differences between the R44 and R66.

Quite noticeable was the new crashworthy seat design, which sacrifices a large portion of space underneath the four seats. This modification is by no means negative as baggage space is compartment behind the cabin.

The structure of theR66 is just over 45 kilograms heavier than that of the R44, but it has about 91 kilograms more useful payload with full fuel. This is due to the fact the R44s engine weighs 227 kilograms compared with the 91 kilograms of the turbine.

I particularly liked the ease of access to the Rolls-Royce 250-C300/A1 engine, which is capable of delivering 300 hp in the five minute take-off rating. Typical Robinson, it has been de-rated to 270 hp.

The first  South African to fly the new helicopter R66, Koos Myburgh,who is the Director, Training at Starlite, in Durban visited the factory in Torrance, Los Angeles, recently for familiarization and check-out training on the R66 prior to the first one ordered by company arriving in the country next month.

Also noticeable at the lower section of the tail booms vertical stabilizer, is a little horizontal aerofoil section. This prevents the nose pitching up during autorotation in the maximum aft C of G configuration.

Only one fuel drain outlet exists and is located on the port side of the R66, the reason being that the 73, 6 US gallon (270 litre), single bladder fuel tanks lowest point is situated in this area. Consumption is advertised to be 24 gal/hour but, according to Tompkins, he never had a consumption of more than 20 gal/hour during the certification test flight phase. This is very good news as it should give an endurance of 3, 4 hours including reserve.

Getting to the rotor head is also much easier due to the steps that were put in place. I also like the micro switches located at all external cowling doors with the LED warning light display in case a cowling door is left in the open position.

Airborne

Starting the machine is extremely easy and simple. For once a MGT gauge has been made easy to read with a decent increase in scale at the limitation section. You can easily monitor the trend of the temperature increase during start, should an over-temperature situation develop.

The start sequences reminds me a lot  of the simplicity that you have in the Euro copter EC130.In fact, the whole engine management/monitoring system from start –up to shut-down ,makes it an ideal turbine for low time pilots. Teaching these pilots basic turbine handling is going to be a walk in the park.

I found that during takeoff, the left skid left the ground quite a lot later than in the case of the R44. The yaw pedals are also remarkably stiffer. No problem was encountered with tail rotor efficiency doing hover turns (wind was about 18 knots?. Tompkins mentioned that the R66 can handle up to 40 knots crosswinds with ease. It was flown sideways at 70 knots during certification.

I recommend that, should you have a heavy passenger, put him/her in the right hand back seat when you do crosswind from the left landings. It would help with the extreme left skid low situation.

Going through transition is pretty much the same as in the R44 .Applying power at 40 knots is when you actually experience the excess power of this machine. With full fuel and applying 83% torque, we had a climb rate of 2,300 feet/minute! Instructors will have to teach their students to get used to quite a significant high nose attitude to maintain 60 knots during the climb. The speed tends to constantly" run away".

Leveling off at 1500 feet, I maintained 83% and we were indicating 135 knots in no time. I pushed the nose forward slightly to reach Vne (140 knots) and did not feel any change in the smoothness nor feel any vibrations. I noticed the remarkable quietness in the cockpit and no high frequency vibration (as caused by the R44s piston engine) on the airframe.

Maintaining the power setting, I completed one 30- and one 50- degree steep turn. Care must be taken not to try and hold back too much on the cyclic as the helicopter tends to climb very easily. The IAS decreased to 115-120 knots during these turns.

Good Manners

Down to 500 feet above ground level (agl), we headed for a smaller airfield where I did a straight –in autorotation.

Now this is the first helicopter that I have ever flown where you do not load the disc during the entry phase from forward flight. If you do, you will over speed the rotor immediately.

Gently lowering the collective, you just keep on easing the cyclic back until you reach 65 knots and then enter the glide. This all comes with minimal height loss.It is going to be such a pleasure to teach this to a student. I did not see any decay in the rotors revolutions per minute (Rrpm) during the initial action. It actually looked like the guage was stuck at 100% Rrpm!

Tompkins said: "I like a high flare…." Which I did. Very nice float; lots of time. Now another amazing part: he opened the throttle after I leveled the machine with about five-foot skid height to go. It took the engine half a second to come online!

There should never be a reason to have a low rpm situation or a late recovery action, resulting in a hard landing. I believe the engine should be online just prior to leveling the attitude and he agreed. It was purely to demonstrate how fast the engine can respond, if needed.

On the go around, I leveled off at 400 feet agl and turned downwind. To teach the turn from downwind is equally as easy: give yourself space so that you do not have to pull back too hard to get the R66 through 180 degrees; it tends to overrev easily. Just turn gently holding the nose back while the speed is reducing.

At about 200 feet agl, the turn was completed .Full contact touchdown without introducing the engine stills sees you with a lot of remaining Rrpm. The low rpm horn came on with about three feet to go to touchdown.

Executing a power-off landing on tar just sounds horrible, but it is a lot safer. If a student loses his directional control on a grass surface, you could easily roll over.

Challenging Exercise

Switching off the hydraulics on the downwind position is going to be only challenging exercise to teach in the R66. I found it extremely hard to control in the rolling plane, doing a hover landing. A skid-on is definitely recommended.

It will be very interesting to see how the fairer sex will cope with this. I also believe when you fly from the instructor's seat that the R66 is easier to control because the instructor can support his elbow much better than when you have just your right hand on your knee.

The engine –out from the four-foot hover is really a non-event. No yaw at all; no significant Rrpm decay till touchdown .Even the one from 15 feet agl was done with no real facial expression change.

Things I Liked

Compared with some other helicopters I have flown , I found eleven things I particularly liked about this R66 turbine, the first being that it is easy to inspect the main rotor head without the need for a ladder. Then there was simplicity in starting the machine coupled with the MGT gauge scale/markings for starting purposes.

Rrpm management during autorotation is very stable and constant and is very forgiving. A big plus is the lack of airframe vibration and the quiet inside cabin during flight. And above all, there is lots and lots of excess power.

Other plus factors in my opinion are the huge baggage compartment; the performance graph is now on the T-bar, not on the panel above the pilot; the landing lights could be left  permanently on; the central warning panel lights with no more "Push to test" lights at the back and, finally ,the seat belt release mechanism is more user friendly.

Possible Improvements

Things I suggest Robinson could consider improving are the fact that magnetic plugs on the engine are difficult to get to and that the battery is difficult to access.

In addition, I recommend that people operating far from an AMO require a ground power unit.

When you order your R66 choose a dark base colour as the exhaust gasses stain the bottom part of the tail boom.

There is very limited space below the occupant's seats and they could be damaged easily by "forcing in" hard objects. suggest that  the area be permanently sealed closed ,but perhaps just leaving that of the pilots seat open for aircraft documentation and other papers.

The seat belt release mechanism is user friendly and a point which I liked. It might be a good idea, therefore, to modify all other "Robbies" to this system as this would prevent confusion on "how to "in the event of an accident.