It may happen never. Given enough speed the planet might have a stable orbit.

Risks are:

• the black hole increases it's mass by continually swallowing matter making the black hole heavier and therefore make before stable orbits unstable
• debris around the black hole slows down the planet

Both isn't terribly likely, as the space is mostly empty.

It may happen never. Given enough speed the planet might have a stable orbit.

Risks are:

• The black hole increases its mass by continually swallowing matter making the black hole heavier and therefore make before stable orbits unstable
• Debris around the black hole slows down the planet

Neither is terribly likely, as the space is mostly empty.