Visa considerations: Getting a Brazilian visa in the States for a retiree flying military standby can be difficult, but Brazil requires a visa even if you are only passing through their country. You may be flying through Brazil for a vacation in Argentina. The embassy requires a name of your Travel Agency, when you are going to travel, where you are going to stay. All difficult questions if you are flying military standby.

Since you will presumably be traveling through Howard Air Force Air Base, Panama there is a better way:

Stay a few days in Panama (see Panama). Have a taxi take you to the Brazilian Consulate in Panama City. Have with you your passport, and a passport photo. There you can fill out your application, mention that you are military retired and will be travelling through Howard, present your military ID card (the agent will make a copy of this to go with your application), $20.00 and in 2 working days return to the Consulate to pick up you Passport with a visa good until you passport expires. The only problem I had with the application was listing a Hotel and a City I was planning to visit. I chose the Holiday Inn, Rio de Janeiro.