The “invasion,”–as critics call it, of thousands of very light jets over the next several years has prompted NBAA to fire a shot across the bow of the Air Transport Association (ATA) for its long-held contention that the emergence of VLJs will overburden the air transportation system in the U.S.

“The unfounded comments by the ATA fly in the face not only of public statements by Federal Aviation Administrator and Marion Blakey but also Congressional testimony by top FAA officials,” said NBAA president Ed Bolen. He went on to describe ATA’s position as “fear-mongering by the airlines [as] part of their broader strategy to pay less for air traffic services, even as they try to seize control of the [air transportation system].”

The rebuke from Bolen came in response to comments by an ATA official, quoted in the general media as saying VLJs would be a “significant burden” and would interfere with operation of the commercial airlines.

In his response, Bolen referenced a quote by FAA associate administrator for aviation safety Nicholas Sabatini in testimony before the Senate Commerce Committee earlier this year. “This system is in place today to accommodate the entry of new aircraft into the National Airspace System,” Sabitini told lawmakers. “This is nothing new for the FAA. It is our day-to-day business.”

Bolen described development of VLJs as “good news on many levels,” noting that it will produce “high-skill manufacturing jobs, make many small and midsize companies more competitive because they can take advantage of business jet travel and strengthen aviation services for many small communities.”

While that battle builds, there seem to be divergent forecasts about exactly how many VLJs will fill the skies in the coming years. Inflight Management Development Center, an independent research firm, predicts manufacturers will build 847 VLJs from now until 2013. Last year’s annual Rolls-Royce forecast takes a more optimistic stance. In its predictions released last fall, Rolls-Royce forsees delivery of some 8,000 “microjets” by 2023. In another study, Forecast International predicts that 3,476 very light jets will be built between now and 2014.

Meanwhile, two very light jets, Cessna’s Citation Mustang and the Eclipse 500, received their type certificates last month. Adam Aircraft is expecting FAA approval of its radical, twin-boom Adam A700 twinjet early next year.