Project 404

{{short description|Covert United States Air Force advisory mission to Laos}}

{{refimprove|date=June 2021}}

{{operational plan

| name = Project 404

| image = Image:Patuxay, Vientiane, Laos.jpg

| image_size = 280

| caption = Patuxay, was built in Vientiane during the 1960s with USAID funds awarded for building a new airport runway. Humorously renamed the "Vertical Runway" by U.S. mission personnel.

| scope = Diplomatic Military Attachés
Strategic

| planned =

| planned_by = United States Department of State
CIA

| objective = Counterinsurgency
Foreign internal defense

| executed = 1966–1973

| executed_by = U.S. Army Attachés
U.S. Air Force Attachés
Air America

| outcome = North Vietnamese Army and Pathet Lao Conquest of Royal Lao Government 1975

}}

{{Campaignbox Laotian Civil War}}

Project 404 was the code name for a covert United States Air Force advisory mission to Laos during the later years of the Second Indochina War, which would eventually become known in the United States as the Vietnam War.{{cn|date=September 2024}} The purpose of the mission was to supply the line crew technicians needed to support and train the Royal Laotian Air Force, while Raven Forward Air Controllers were brought in to supply piloting expertise and guidance for running a tactical air force. The two programs together comprised Palace Dog.

Image:HoCMT.png running through Laos, 1967]]

Project 404 began in 1966, as a successor after the completion of Operation White Star, was narrower in scope, and was an adjunct to the various covert ground operations succeeding White Star. Because Laos was ostensibly a neutral party to the conflict between the United States and North Vietnam, the airmen did not wear United States Air Force uniforms, but instead worked in civilian clothing.{{Cite book|last=Celeski|first=Joseph D.|url=https://www.worldcat.org/oclc/1107991323|title=Special air warfare and the secret war in Laos : air commandos, 1964-1975|date=2019|others=Curtis E. LeMay Center for Doctrine Development and Education, Air University. Press|isbn=9781585662906|location=Maxwell Air Force Base, Alabama|oclc=1107991323}}