Lost data on one of the RAID drives, why do I have to send in all of the RAID drives for recovery?

In most RAID disk failures, the failure isn’t a complete catastrophe and the user can still easily access data within the RAID. RAID systems are typically used for speed and/or redundancy of data. As a result, they can sometimes have a catastrophic failure, such as corruption of the RAID array or multiple disk failure in which your data isn’t accessible. If this type of failure occurs, and you are not able to see the redundant mirror image of the data within the RAID, something serious has happened. In this scenario, rebuilding the array with each independent disk included is the only way possible. For that reason, you will need to send in all of the RAID drives for recovery.