| After you have test-flown and done the initial trim changes to the aircraft, use the trim chart below to begin trimming your airplane. Following and adhering to this chart will result in the ability to diagnose trim problems and correct those problems using the simple adjustments shown below. Making these observations and related corrections will result in a straighter and truer flying airplane. |
|
TRIM FEATURE |
MANEUVER |
OBSERVATION |
CORRECTION |
|
Control Centering |
Fly general circles and random maneuvers |
Try for hands-off, straight and level flight |
Readjust control linkages so the transmitter trim levers are centered |
|
Control Throws |
Fly random maneuvers |
A) Too sensitive, jerky controls
B) Not sufficent control |
If A) Adjust linkages to reduce control throws
If B) Adjust linkages to increase control throws |
|
Motor Thrust Angle* |
From straight and level flight, chop the throttle quickly |
A) Airplane continues in a level path for a short distance
B) Airplane pitches nose up
C) Airplane pitches nose down |
If A) Engine thrust angle is correct
If B) Decrease down-thrust
If C) Increase down-thrust |
|
Center of gravity and longitudinal Balance |
From level flight, roll to a 45` bank and neutralize the controls |
A) Airplane continues in the bank for a moderate distance
B) The nose of the airplane pitches up
C) The nose of the airplane |
If A) Trim settings are good
If B) Add nose weight
If C) remove nose weight |
|
Yaw** |
Do inside loops using elevator. Repeat test doing outside loops from an inverted entry. |
A) Wing is level throughout
B) Yaws to right in both inside and out side loops
C) Yaws to left in both inside and out side loops
D) Yaws to the right both inside and out side loops
E) Yaws to the in inside loops and yaws to the right in outside loops |
If A) Trim settings are good
If B) Add left rudder trim
If C) Add right rudder trim
If D) Add left aileron trim
If E) Add right aileron trim |
|
Lateral Balance |
Into the wind, do tight inside loops |
A) Wing is level and plane falls to either side
B) Plane fall off to the left in loops. Worsens as loops tighten
C) PLane fall off to the right in loops. Worsens as loops tighten |
If A) Trim Setting are good
If B) Add weight to the right wing tip
If C) Add weight to the left wing tip |
|
Aileron Rigging |
With the wing level, pull to a vertical climb and neutralize the controls. |
A) Climb continues along the same path
B) Nose tends to go toward an inside loop
C) Nose tends to go towards an outside loop |
If A) Trim Setting are good
If B) Raise both ailerons very slightly
If C) Lower both ailerons very slightly |
|
* Motor thrust angle and center of gravity interact. Check both.
** Yaw and lateral balance produce similar symptoms. Make certain both elevator halves are even with each other and that they both produce the same amount of control deflection throughout the complete deflection range. Right and left referances are as if you were in the cockpit. |
