Yes you can get the TN visa at the Ottawa airport, however the process may take well over 4 hours. If you are under a tight schedule, I suggest you get the visa first at the border, say Ogdensburg, NY (end of highway 16, over the bridge to USA, just south of the 416/401 junction).
Typically these documents are required:
1. An employment letter: detailed description of the position, including job responsibilities and minimum requirements
2. A copy of the prospective employee's C.V.
3. Evidence of the employee's highest academic degree awarded in the form of transcripts or a copy of the actual diploma.
(Original copy! The INS officer will make a copy and hand back the original to you)
4. Evidence of the employee's Canadian citizenship (copy of passport, birth-certificate, etc.)
This is what they want to see on the Employment Letter
1. The Profession which the applicant is coming to fill.
2. A Description of the professional activities and/or duties which the applicant will perform
3. The anticipated period of stay
4. The salary which the applicant will be paid during the course of their employment and
5. Any benefits the applicant will receive in addition to salary, i.e., vacation and sick time, retirement benefits, and any others that is received from employment.
NB:
1. The intended U.S. position must fall within the list of
TN professions in “Schedule 2” of the North American Free Trade Agreement (NAFTA). Commonly used categories include Computer Systems Analyst, Engineer, Economist, Accountant, and Management Consultant.
2. The TN applicant must have the specified credentials for the stated profession, per Schedule 2. Typically the minimum requirement includes possession of a bachelor’s degree.