| No. | Cause | Fix | Comment |
| 1 | Undercarriage alignment error. | Ensure U/C axle line is perpendicular to fuselage | If the undercarriage has been knocked or bent, for example with a rough landing, then tracking will have been upset. Check by looking at the undercarriage from underneath the fuselage to ensure the axle line is perpendicular to the longitudinal axis of the fuselage. |
| 2 | Excessive engine right thrust. | Decrease engine right thrust. |
The usual amount needed is about two degrees. This is not guaranteed however, as there are other factors. E.g. if the aeroplane has power in reserve then more right thrust is usually needed. If this fault is diagnosed, proceed carefully with small reductions in right thrust, flight testing at each stage. To understand the need for right thrust and the importance of getting it right, see Point 2 in the related article > Tracks Left on Takeoff Run |
| 3 | Excessive friction on right main wheel | Lubricate main wheels. | If the starboard wheel has high friction it will create drag. The wheel will become a fulcrum and the aeroplane will yaw to the right, (starboard). |
| 4 | Fin alignment error. | Correct the fin alignment. |
Check visually by sighting centrally down the fuselage from the front of the aeroplane. If the fin is offset, the offset will be visible. A quick temporary fix for this condition is rudder offset. Once the fault is correctly diagnosed, the pilot will typically make small adjustments until the ground tracking is correct. Note: Building errors like this should ideally be picked up before the maiden flight. Note a second possibility is the banded tailplane. Here the fix is to key the tailplane to the fuselage such that once banded on it cannot move. |
| 5. | Wing warp. | Correct the wing warp. |
If one wing is warped it will create extra drag and turn the aircraft. If an aircraft with this condition gets airborne it will be considerably out of trim and will require fast action by the pilot at the trims to get the aircraft flying. Note: Building errors like this should ideally be picked up before the maiden flight. |
Link to related article > Tracks Left On Takeoff Run
Comments
24th. April 2016
Added points 4. and 5.
Article tidied and improved with added detail.
The idea for point 4., fin alignment, is contributed by Adrian Smith.