Boston-based charter broker Magellan Jets last month launched its Voyager Program, which entitles members to guaranteed hourly rates on various aircraft; a scheduled departure guarantee (or a 10-percent discount on the traveler’s next flight); three aircraft upgrades per year; concierge service; and one-way and round-trip pricing. The membership fee is $250,000, and the company claims to charge 15 to 20 percent less per hour than other membership or fractional ownership programs.