iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2016-03-31T16:54:12Z. The update package is 1.15 GB. This is a delta (partial) update that requires 8.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f3e7bc38930f43a7f761e636bf337cad09855076.zip.