What is the maximum nose wheel deflection angle?
For the B787, the maximum steering angle is 70°. This information can be found in the Airport Planning Manual:


  


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For the A380, which has also a steerable main landing gear, the nose gear steering limit is the same:


    


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The center of the turn is off center, at the level of the main landing gear. With a multiple-boogie landing gear the main gear slips on the ground, which is not desirable.

This effect also occurs with a single bogie, unless the wheels are steerable. Limiting the steering angle also limits this slippage, and the wear going with it.