With the anxiety of the ailing airline industry turned up for the fall season, Virgin America has kicked off its own late summer/fall sale, with one-way fares from Boston to either San Francisco or Los Angeles going for $119 or $139, with the higher price being for travel on Friday or Sunday and the lower for flights all other days.

The discounts, which require a minimum three-day advance purchase, are available for travel from Aug. 18 to Nov. 18, and tickets must be secured by Aug. 11.

Besides featuring a range of onboard media choices, Virgin was the first carrier to offer inflight WiFi on all flights. There is a fee involved for the service but if you can’t live for even a few hours without the Net this is good news.

This move by Virgin represents just the latest in a series of sales launched by US carriers amid growing worries over the effect the recession will have on fall travel in which sales historically tend to slow after the heavier summer season.

Heightened industry concerns about the fall became apparent after Southwest leaped in with a no-holds-barred 48-hour sale earlier this month, triggering a small fare war. That sale, coming earlier and with more flexible (read aggressive) terms than autumn sales in past years, was widely viewed by analysts as a push by the industry, already struggling with sluggish sales and increasingly volative fuel prices, to fill seats.

Delta also announced a systemwide fall sale, but this one focuses on leisure travel so comes with longer advance purchase times.

For domestic travel, you must buy at least 21 days in advance but no later than Aug. 14 for travel from Aug. 18-Nov. 19. Web fares on select seats are $59–$194 each-way, based on a roundtrip travel.

And internationally, tickets must be purchased no later than Aug. 3 for trips Aug. 18-Nov. 30, except Europe for which travel must end by Dec. 18. Web fares are $159–$429 each-way, based on a round-trip.