Apple has released MacBook Air Flash Storage Firmware Update 1.0 for mid 2012 models.
About MacBook Air Flash Storage Firmware Update 1.0
This update is recommended for MacBook Air (mid 2012) models. This update addresses a storage firmware issue that, in rare cases, may cause a system to fail to recover from a crash.
Your MacBook Air requires this update.
The power cord must be connected to your MacBook Air and plugged into a working power source.
Back up the data on your MacBook Air flash storage to an external disk or Time Capsule before installing this update. If you’ve already backed up your data, click Install Update to begin the update.
Do not reset, shut down, or turn off the power to your MacBook Air while updating your flash storage. If there is a problem during the update, your flash storage may become unusable and all the data on it could be lost.
When the update is complete your MacBook Air will shut down. Wait one minute before restarting it.
Boot ROM or SMC Version Information: After the update, you will have Revision TPVABBF0.
You can download the update by selecting software Update from the Apple Menu at the top left of your screen.