Sentient, a leading provider of business aircraft transportation through membership block charter, was purchased last month from CSFB Private Equity by TH Lee Putnam Ventures, a New York-based private equity firm. Sentient claims more than 1,400 aircraft available from among its approved charter aircraft providers. Participants in its Private Jet Membership purchase TravelCards valued at $100,000, $250,000 and $500,000, respectively. The cards are debited, based on the hourly rate for the business jet used.