aircraft banks to right and requires 4 unit of rudder trim

[mr fix it]

we have aproblem with one of our classics when flaps are extended 30 - 40 aircraft banks to right and it requires 3 to 4 unit of rudder trim . ndt of flap spindles is ok , all spoilers are flush , aileron & rudder are neutral . i/b te flap clutch mechanism is ok . sequening of fore flap is ok ? any advice guys

[sjap]

4 units is a lot!
Are you sure the carriage spindles are ok? see
http://www.sjap.nl/57.htm#Broken

Then check the outb aft flaps A-frame (they can become loose) and actuating rods.
Also make sure the aileron wing cables have the correct tension. It happens that they become very low, and the aerodynamic effect of the ailerons is much less with sloppy cables in combination with flaps lowered.
All slats extend to their correct position? No slat misalignments or skew?
spoilers are flush on ground but in air? No floating spoilers?
have the Inboard aftflaps the same play / deadweight play, this can cause assymetrical forces as well.

Let us know what you found
best regrds
sjap

[mr fix it]

complete rigging of TE flaps solved the problem .