Generally, it takes several years to accomplish this as you must first be qualified to work in the U.S. As a practical matter, most foreign-based flight students have an available, fully-qualified U.S. applicant who can sign the obligation and be fully responsible for making the monthly payments.
Individuals just starting to establish a credit history usually must begin with smaller types of accounts, like revolving credit cards or retail charge accounts, or more secured transactions, like auto loans or mortgages.