Project Insight was a secret S.H.I.E.L.D. operation initiated in direct response to the growing need for national security that began after the Battle of New York. Agents required a Clearance Level over Level 8 to access the Helicarrier Bay in the Triskelion. It is presumed that only S.H.I.E.L.D. Level 9 and Level 10 agents know about Project Insight, as well as most likely most HYDRA agents undercover, posing as S.H.I.E.L.D. agents.
Project Insight involved three heavily armed, satellite-linked Helicarriers designed to proactively strike out against potential threats to the United States of America before they actually happened. In 2014, the project was to be put into effect, but through the actions of a HYDRA infiltration, the operation was turned against S.H.I.E.L.D.. HYDRA planned on using Arnim Zola's algorithm to root out individuals that would oppose or threaten HYDRA's goals. The algorithm used every variable of a person's life such as bank records, voting patterns, and even standardized testing scores.
There were at least 715,854 individuals targeted. While attempting to justify his actions to Nick Fury, Alexander Pierce suggested that Project Insight would kill approximately 20 million people in total.
The three Helicarriers were launched from an underground launch facility next to the Triskelion on the Potomac River. Once they reached a certain altitude, their guns would fire on all potential targets HYDRA deemed a threat to their plans.
Thanks to the actions of Captain America, Black Widow, Falcon, Nick Fury and Maria Hill, the three Helicarriers had their targeting systems changed to fire on each other. All three Helicarriers were destroyed and all HYDRA agents aboard them were killed, plunging into the Potomac River. One also crashed into the Triskelion, damaging it.