The Air Force Special Operations Command (AFSOC) has cancelled without an explanation its planned order of 2,861 iPad 2 devices.
The tablets, originally scheduled for delivery in late February, were meant to become personnel electronic flight bags that replaced hefty paper charts and technical manuals.
They would have been used in surveillance aircraft and helicopter gunships, according to the Wall Street Journal.
The cancellation came just days after government technology website, NextGov, raised questions about security risks associated with the planned use of Russian-developed document viewer software, GoodReader.
Fears over the software were raised after the director of the Army’s smartphone project, Michael McCarthy, said he would not use software developed in Russia due to the potential risk to end users.
An Air Force spokesperson told NextGov that it would continue exploring options for the electronic flight bags while ensuring the devices “do not introduce unnecessary risk”.
GoodReader may be developed in Russia, however it is also one of the most well known document viewers that supports encryption in iOS Data Protection.
Security analyst Bob Walder from NSS Labs gave the product a tick of approval for its use at least in corporate environments because documents stored in the GoodReader sandbox are encrypted -- a feature that set it apart from many other apps that claim to be business class.
GoodReader developer Yuri Selukoff has scoffed at any claim that his software contains malicious code.
"I am not affiliated with any government institution, neither Russian, nor any other," Selukoff told NextGov.
"GoodReader doesn't have any malicious code built into it. Having said that, I am open to any security/penetration tests that anyone would be willing to perform on the app."
Software components aside, the US Federal Aviation Administration approved iPads as electronic flight bags for commercial airlines mid last year.