iPadOS 11.3 (build 15E5216a) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2018-03-16T17:04:59Z. The update package is 50.16 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c594385a9834d9cab4d3627d769bff35f442ffcf.zip.