What is the maximum nose-wheel angle of deflection on modern commercial aircraft such as the Boeing 787? Can it deflect to 90 degrees or even more?
For the B787, the maximum steering angle is 70°. This information can be found in the Airport Planning Manual:
For the A380, which has also a steerable main landing gear, the nose gear steering limit is the same:
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.