He was a member of the Sandinista National Liberation Front (FSLN), and is best-known for his unsuccessful hijacking of El Al Flight 219 alongside Palestinian militant Leila Khaled on September 6, 1970.
Argüello's family was part of an exodus of affluent Nicaraguans, fleeing the country for the United States, where they settled down in Los Angeles.
In the summer of 1970, Argüello and a small group of Nicaraguan FSLN émigrés made contact with a different faction of the Palestinian guerrilla movement: the Popular Front for the Liberation of Palestine (PFLP).
The Nicaraguans wanted additional guerrilla training, which the PFLP agreed to provide in exchange for the FSLN's participation in the Dawson's Field hijackings.
Posing as husband and wife, they boarded the plane using Honduran passports — having passed through a security check of their luggage — and were seated in the second row of economy class.
Pilot Uri Bar-Lev, upon learning of the hijacking in progress, refused to concede to Khaled's demands to open the cockpit door and instead threw the plane into a steep nosedive to throw them off balance.
[1] In 1972, the Japanese Red Army and the Popular Front for the Liberation of Palestine (PFLP) killed 26 people and wounded more than 80 in the Lod Airport massacre.
In 1983, after the Nicaraguan Revolution, the Sandinista National Liberation Front commemorated Argüello by renaming the geothermal plant at Momotombo in his honor.
However, after the 9/11 attacks against the United States, the Nicaraguan government of Arnoldo Alemán removed the name of the plant, claiming it was wrong to honor a terrorist.
He is a symbol for the oppressed and deprived masses, represented by Oum Saad and many others coming from the camps and from all parts of Lebanon, who marched in his funeral procession.