iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2015-10-21T17:15:54Z. The update package is 1.13 GB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 649c4bc5f22b9bbe7db2cf2d6303555c4ffd0e64.zip.