He was an Apache helicopter pilot.

Source: https://calgarysun.com/opinion/letters/letters-jan-17-prince-harry-has-done-some-amazing-stuff

In the memoir, Harry says he killed more than two dozen people when he was an Apache helicopter pilot during his second tour of duty in Afghanistan.

Source: https://www.independent.co.uk/life-style/royal-family/prince-harry-afghanistan-family-security-b2257177.html

It has since been revealed the Prince was allowed to leave his Apache helicopter base after it was put in lockdown when random drug testers arrived.

Source: https://www.thescottishsun.co.uk/news/10025392/harry-ambushes-impacted-queens-health-sources-say/

Prince Harry was permitted to leave his Apache helicopter base on 'urgent palace business' when it was put on for a spot drugs test, it has been claimed.

Source: https://www.dailymail.co.uk/news/article-11608249/Prince-Harry-allowed-miss-drugs-test-leave-UK-RAF-base-lockdown.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

The record distance of the shot was then confirmed by an Apache helicopter, which hovered over the firing position, using its laser range finder to measure the distance from it to the target.

Source: https://www.dailymail.co.uk/news/article-12774437/The-deadly-art-sniper-Ukrainian-marksman-claims-record-assassination-2-6-miles-incredible-long-range-kills-Taliban-fighter-taken-8-120ft-five-ISIS-fanatics-blown-suicide-vest-hit.html?ns_mchannel=rss&ns_ca