Apple is warning customers that solid-state drives in some MacBook Airs are failing and is offering free replacements.The company said that 64GB and 128GB SSDs were failing in MacBook Air laptops sold between June 2012 and June 2013. The drives will be replaced free, the company said in webpage about the SSD recall.The laptops involved are the previous generation of MacBook Airs, which ran on Intel Ivy Bridge processors. The failure affects users in all countries where MacBook Airs were sold. Users can visit an Apple Store, an authorized reseller or contact the company to replace the SSDs.Users can determine if their drives are affected through firmware available at the Mac App Store. Users can click on Updates at the Mac App Store and choose "MacBook Air Flash Storage Firmware Update 1.1," which will check the drive.Apple is recommending users back up their data a