Today’s NY Times (registration req) reported a surge in interest in charter cards, citing results from Delta AirElite, Sentient Jet and JetNetwork and OneSky. Charter cards are a twist on the fractional card concept pioneered by Marquis Jet.

The article ends with an anecdote from Sentient Jet CEO Steven Hankin, who had an imminent commercial flight from Orlando when the latest terrorist threat emerged. Anticipating a mess at the airport, he quickly shifted to a private Sentient Jet flight.

Why in the world, then, would the top executive of a private-jet company even contemplate flying commercial, as Mr. Hankin had last week?

“It’s expensive to fly privately,” he said.

It’s quite common to fly a blend of commercial and private aviation. In certain cases, the cost savings of commercial may outweigh convenience and productivity benefits. We hear often that flyers will look to commercial when flying with just 1-2 passengers, or on especially long trips, especially between cities served by major airports. On the other hand, they may rely on private for shorter flights with 4-8 passengers, or between smaller airports.

“If you’re flying to London, it’s going to eat up your whole day anyway,” said a fractional owner in Northern California, “the incremental hassle of standing in line for 45 minutes isn’t that big of a deal.”

Even within private aviation formats, blending is common among heavy flyers. Some clients own a fractional share, hold a jet card, tap ad-hoc charter for select trips, and occasionally travel commercial when flying solo.

The fractional plane is their default mode, for family trips or small groups. The card allows for additional hours beyond the fractional allocation, and can be configured for larger or smaller planes. Ad hoc charter is used for especially efficient trips, where the special features and guarantees of fractional/card programs are unnecessary.

For first-time flyers, a card program such as Sentient Jet Membership offers a relatively low cost entry point to private aviation. A $100,000 deposit gets you started, and funds may be refunded at any time without penalty.