Zenith Aircraft Builders and Flyers
Flying in the wind !
On October 12th, 2012, I decided to go flying.
10 knots winds gusting to 21 knots.OAT 36F.
I still had to fix the slight turn to the right problem and then I would take the little bird to the sky for a spin.
I unscrewed 1 turn on the left aileron; problem fixed !
Got on board for a test flight. A Cessna C-150 (instructor/student) was doing circuit work so I asked them how the winds were....TRES SPORT, I was told.
Lined up the runway, went to full throttle and lifted off. Wooooo !!!
The CH701 doesn't mind crosswinds and gusts ! That's nice. The takeoff was straight and holding the nose on the middle line was accomplished using some rudder and the 701 held the line very well.
In the air, you can feel the 10 knots winds but not as much as I tought I would. The 20 knots gusts were more annoying than anything else. There again, the 701 held its own. WIth reduced power, I could achieve 80 - 90mph easily. I went up to 2000ft and flew around the airfield for a while getting the fell for the gusts vs controls.
It was now time for the landing, which I did using the crab/low wing in the wind approach.
I kept the power on till the flare and, even with the gusts, it was a non event.
All the gauges were in the lower GREEN due to the OAT. That was to be expected.
Lessons learnt : in gusty conditions, my 701 doesn't have enough aileron deflection...The response is way too slow and the stick has to go to FULL for the input to command a quick movement from the plane. This is not acceptable; the fix is to modify the bicycle control behind the seats to get more deflection with the smaller stick movements.
Second lesson : do not leave the fuel shutoff valves ON...The gravity will work its magic and flood the engine... Don't ask how I know this. Suffice to say that undoing 4 plugs on a Subaru takes 1.2 hour...(including cowl removal, cleaning plugs and flushing fuel from the engine).
I decided not to go back flying in gusts before doing the aileron modification; marginal aileron control and gusts don't mix !
Final tought : the 701 has very good stability even in moderate crosswinds and gusty conditions. I didn't think this light plane would handle that well !
I really like the way the 701 handled marginal weather conditions.
Until next time,
Normand
Joe Byrd
How do you recommend modifying the bicycle control?
Oct 13, 2012
Normand Lambert
Hi Joe,
My 701 has dual control sticks which means that the stick sits between my legs. This doesn't give a lot of space for movement. When the center "Y" stick is used, you can get full deflection (left - right) without hitting anything. The top of the stick can move almost 5 inches both ways and so you get the full deflection easily.
The bellcrank control(behind the seats) is basically transmitting the stick movement from the lower (stick) bellcrank to the two aileron bellcranks at the top. Look at drawing 7-C-0 to see the details for this. On each bellcrank, the distances between the control rods are equal (side to side) meaning the input movement of the stick equals the aileron movement. By moving the control rod (from 7-C2-3) inward on 7-C1-4, a smaller movement on the stick will command a larger movement on the ailerons.
So, my idea is to move the rods from 7-C2-3 INWARD on 7-C1-4. By how much ???
Still have to figure this one.
I'll keep you posted.
Normand
Oct 13, 2012
Bob McDonald
Norm
When you run out of aileron in a X-wind.... just approach at a higher airspeed on final. This gives both the rudder and aileron more authority. Fly the final wing low into the wind, airspeed 65 - 75 mph as you would landing on an aircraft carrier. Once your mains are down, chop the power on it will settle and stay planted on the runway.
Oct 13, 2012
Normand Lambert
Hi Bob,
I have no problem with this procedure... My main concern is the delay of a few seconds between the stick input and the aircraft response. The lag of a few seconds makes me very uncomfortable and this is what I need to fix. This 'lag' is present at all speeds and attitude. Obviously more stressful near the ground in gusty conditions...
Let you know !
Normand
Oct 13, 2012
Harmen van der Velden
Oct 13, 2012
Ronald Steele
Keep in mind that the changes you propose will increase the stick forces on the ailerons. It will change the feel of the plane. Zenith recently changed the 6xx aileron bell crank the opposite way, requiring more stick movement for the same amount of roll. This change was made to give the controls a more balanced feel between roll and pitch.
Ron
Oct 17, 2012