Apple fixes USB HDD issues with AirPort Extreme, Time Capsule firmware update
In a firmware update issued on Thursday, Apple addressed a few minor problems with its newest 802.11ac AirPort Extreme and AirPort Time Capsule base stations, including a problem with USB hard drive connectivity.

According to the release notes, Apple's firmware update 7.7.2 applies to AirPort Extreme and Time Capsule Wi-Fi base stations that support the 802.11ac protocol.
The most pressing issue fixed with the update is a bug that prevented USB hard drives connected to an AirPort from appearing as an available disk in Time Machine. Apple's base stations allow users to connect external hard drives to maximize storage space, or make more storage available wirelessly.
Also addressed is an issue that caused intermittent WAN outages for some users, and another that resulted in a network loop.
Apple's firmware update 7.7.2 is available for download now from Apple's Support Downloads webpage.

According to the release notes, Apple's firmware update 7.7.2 applies to AirPort Extreme and Time Capsule Wi-Fi base stations that support the 802.11ac protocol.
The most pressing issue fixed with the update is a bug that prevented USB hard drives connected to an AirPort from appearing as an available disk in Time Machine. Apple's base stations allow users to connect external hard drives to maximize storage space, or make more storage available wirelessly.
Also addressed is an issue that caused intermittent WAN outages for some users, and another that resulted in a network loop.
Apple's firmware update 7.7.2 is available for download now from Apple's Support Downloads webpage.
Comments
How can they make USB 2.0 HW become USB 3.0 with a SW update?
magic, silly.
Fixed. Bandwidth of 2.0 is plenty for a traditional HDD. This ain't a spec war
Clearly you've never archives 2+ Terabytes using the Time Capsules USB port. Try it. Then respond.
Hopefully this will be fixed soon.
If accuracy is what you came for...this ain't the place to find it.
AirPort Express has an USB Drive support??
Not fixed. Still USB 2.0.
They didn't say they were upgrading to 3.0.
If it were 3.0 they'd still work with it the way Apple implements them.
Just doin' my part to make the world a better place... ;-)
You're right, the Express doesn't support HDD's... They've since corrected the article's title to "Extreme" instead of "Express"...
I have problems with USB drives showing up on 3rd gen AirPort Extreme so it doesn't surprise me there's still a problem.
Could you make any less sense? This is referring to 6th Gen AEBS & Time Capsule units.
There has never been very solid support for USB drives connected to any AEBS or Time Capsules EXCEPT FOR this latest 6th generation "tall" models, with 802.11ac.
Time Machine backups to external drives has NEVER EVER been supported until this latest edition....and network sharing of files by attached drives has NEVER EVER functioned the way some people think it does (Its not a NAS).