THANKS TO AN added ingredient called competition, airlines all over the country have been coming up with imaginative ways to attract customers -- including the old-fashioned trick of underselling each other to attract customers. Flights of fancy have become no-frills realities, families have taken advantage of go-anywhere package deals on tickets, and spouses and offspring have been tagging along on business trips. Now a new airline -- New York Air -- has announced plans for flights between here and New York for one-way fares as low as $29.

This could be the start of something small -- smaller, in fact, than the cost of driving. For someone traveling alone in a car that gets, say, 16 or so miles to the $1.35 gallon, when you add in all the tolls (not to mention wear and tear, time and the price of all that plastic food on the turnpikes) the low route to New York may well be more expensive than going there by air.

This doesn't mean that everyone will park-and-fly from now on. Group travel by car as well as train and bus fares will prove more attractive to many travelers; and the $29 fare is proposed only for weekends and weekday evenings, with a regular weekday fare of $49. But if approved, this new service will offer the first serious competition to the heavily used Eastern Airlines shuttle, which has enjoyed a near-monopoly on the route; the current shuttle fare is $60, with an excursion rate of $78 for a round trip made in a single weekend.

Officials at Eastern say, "We're studying the whole thing" -- which is precisely what airline deregulation is supposed to stimulate, and which may result in still more attractive proposals for service between the two cities. In the meantime, fasten your seat belt, put your chair in an upright position and see where the next fare wars take us.