New, Response from ZAC, See bottom
Thanks Kent
I got a chance to fly an XL the other day. I figured I ought to fly it first before I make the big plunge. Kent Bauer was gracious enough to let me fly. What a wonderful aircraft. He has about 70 hours on the aircraft. He has really done a fantastic job. His workmanship is superb. I was very impressed.
From what I have read I was a little concerned about the head clearance of the canopy, rudder placement, throttle placement, and the Y stick in the center. But after I sat in it these all went away. I am 6 ft and 230 and had no problems with anything. The head clearance was fine, and the seat position including rudder pedals were very comfortable and natural. I was thinking about going with the dual stick installation but after flying the center stick I will not waist my money. I thought it was very natural. .
It was a beautiful day, just begging to fly. The first thing that impressed me was the Jabiru 3300. Started up on the first try and purred like a kitten. What a great engine for this aircraft. Kent took it up and we flew around a little bit. We were at max Gross Weight and the CG was towards the aft end. We did some stalls and steep bank turns. The first this thing I noticed was the pitch sensitivity. More on that later. We came back in and swapped seats. I started it up again and taxied out, pushed up the power and rotated about 60 knots. I have read about the tendency to over-rotate and sure enough did it. It wasn’t bad but something to get used to. This visibility is superb. I grew up in a bubble canopy with the T-37 and 38. The visibility is fantastic. Got to love a low wing! There is no need for a flap gage. Just a quick look at the wings confirms the position. Did I mention the great visibility.
Once we got out of the traffic pattern at Kingman Ks, we went out and did some steep bank turns to get used to the pitch sensitivity and after a series of them it felt pretty good. The ailerons are kind of stiff as well as the rudder. The rudder will kind of stay where you put it and takes a while to center up. The control harmony is a little off. It could stand some tweaking. I also did some stalls. Very honest, no surprises. Over all impression was what a nice flying aircraft. Even with the control harmony issue the aircraft was very responsive and a joy to fly. We headed back to the pattern and did a bunch of touch and goes. It took a couple to get the hang of it, but I was satisfied after a few. We had a little cross wind and it was very controllable. Most of my issues were with finding the flare picture. I am used to flying bigger aircraft where I am sitting about 15 to 20 feet higher. But after I got the picture it was really a joy. We then headed out to the west to cruise a bit. We leveled off and let it accelerate out and pulled the power back to 2800 on that sweet sounding Jabiru. We cruised at about 140 to 145 mph. Very impressive. We dropped into Pratt and did a couple more T&Gs and then brought it back to Kingman. What a nice flying little aircraft.
Bottom line; I bought the rest of the kit. There are some small quirks (control harmony) but nothing really big. I have to believe that some are fixable. The visibility, the cockpit comfort, the responsiveness and the solid feel of the aircraft are exceptional. Plus the Jabiru is really a nice engine for this airframe.
Can’t wait to get the rest of the kit and start building
Here is an Email response from ZAC
> Message: Request Additional Info, I got a chance to
fly an XL the
> other day. I figured I ought to fly it first before I make the big
> plunge. What a wonderful aircraft. So I placed an order for the rest
> of the kit. I was very impressed.
> I did have a couple of questions though. The control harmony is a
> little off. The elevator is very sensitive and the ailerons are
> stiff. I got used to it fairly quickly. I did a series of steep bank
> turns. After a couple of roll ins and roll outs it felt better. The
> landings went fine. However, I have to think that reducing the
> elevator authority might be a good idea.
You are right, elevator authority increases as the airspeed increases.
In cruise, pitch control is generally done with making small adjustment
with the electric trim tab.
> Have you observed this? Do you have any
recommendations on how to
> improve this? Do the hinged ailerons decrease the roll forces?
Yes, using piano hinges instead of the flex hinge will decrease the aileron
forces; with the flex hinge the forces increase progressively with the bank
angle. On our demo flights, pilots have responded positively to the solid
feel of the ailerons.
Without complicating the control system, aileron sensitivity can be
reduced by increase the stick movement by making the length of the stick
longer.
> One more impression, I thought the rudder was kind
of stiff. It would
> almost stay where you placed it and did not really seem to center when
> you took your feet off the rudder. Again it wasn't that big of a deal
> but noticeable.
> Have you observed this and do you have any fixes?
This is due to the direct linkage of the rudder pedals to the steerable nose
wheel. For the most part, it is necessary to coordinate turns with rudder -
turns are initiated with the ailerons, and for the most part the slip
indicator
(bubble) will just begin to move.
The nose gear centering stops can be filed down to make the nose rudder
pedals easier to move.
> Bottom line; I bought the rest of the kit. These
small quirks are not
> big ones. But I have to believe that some are fixable.
Nick Heintz
Zenith Aircraft Company
And another comment on the rudder stiffness from Norman.
--> Zenith-List message posted by: "norman"
<normskiroo@ukonline.co.uk>
Hello Matt,
We here in the UK have had problems with friction in the rudder control
circuit, mine was very stiff originally and the problem was traced to the
bottom plastic bearing being to tight.
( I am assuming here that CZAW XL kits have the same design bearing)
If you raise the nose of the aircraft so the nosewheel is clear of the
ground then have a second person turn the nosewheel to it's fullest extent
both port and starboard it should spring back to centre when let go.
If this is not the case, slightly slacken the bolts that hold the plastic
bearing together and carry out the test again, if the nosewheel now springs
back to centre then try lubricating the lower bearing, re-tighten and
re-test, if that fails you will have to remove the bearing and have a little
material machined out.
Hope this helps,
Cheers,
Norman