How many checks and balances?
Why should there be a limit?
The controller was already there, and in his own judgement, if he wasn't doing other tasks he might have been able to detect that the aircraft was lined up on the wrong runway.
Why not support him by:
- Not putting him on a schedule resulting in 2 hours of sleep in 24 hours on the backside of his circadian rhythm
- Making available a second controller to share his workload, per FAA guidelines
- Giving him time & space to observe critical phases of flight, instead of doing admin tasks
- Providing additional tools / technology to detect wrong runway incursions
49 people perished on that crash. If another set of eyeballs
had a chance to prevent the accident, why not take advantage of that?