The Flight Standards front office thinks this should really be directed to the BLS," said the Federal Aviation Administration (FAA) official responding to my request for an interview. BLS refers to the Bureau of Labor Statistics, and my query dealt with the lack of distinction in the BLS statistics between FAA-certificated mechanics and those who are not.

The FAA's response comes under the heading of "an action passed is an action complete." It's apparently a subject the FAA prefers not to talk about, although we are on the eve of a 10-year employment survey - this one in 2007 - that will in large measure provide for another decade an inadequate picture of the aircraft maintenance workforce.

Pilots must have an FAA certification, so by definition the BLS statistics present a reasonably accurate picture of the pilot workforce. But, as one cynical wag quipped, "A pilot never returned an airplane better than he got it; mechanics have to all the time."

And the mechanic who certifies the airplane as airworthy, regardless of who worked on it, is FAA certified. Left unsaid in the regulations is that the technician who approves an airplane for service is graded on a 99.999 percent accuracy rate. The FAA tolerates no human error, no bad days, and no excuses if the airplane is found to be unairworthy after the work was done. It would be useful to know the proportion of the roughly 106,000 aircraft maintainer workforce held to this standard.

As a 1997 point paper by John Goglia, then a member of the National Transportation Safety Board (NTSB) and now with the Professional Aviation Maintenance Association (PAMA), submitted to the BLS noted, "Uncertificated mechanics have a limited amount of training, and they are usually restricted to performing only one or two job tasks, such as rebuilding wheels and brakes, or painting or servicing the aircraft."

Goglia and PAMA have been pounding on the issue of knowing the number of FAA-certificated mechanics since 1988.

The FAA knows that more than 375,000 certificates have been issued since 1927, when mechanics were first certified. However, there are no requirements under the Federal Aviation Regulations for periodic registration of mechanics.

Thus, the FAA has no real way of assessing whether there's a shortage of licensed technicians, or how deep that shortage may be by region. And this lack of knowledge comes at a time of two critically important trends. One, the FAA-licensed schools are turning out fewer aviation maintenance technicians. In 2004, some 6,400 airframe and powerplant (A&P) mechanics were graduated; 10 years ago the number was about 14,000. At the same time the most experienced FAA-licensed technicians are facing retirement, there are fewer trained people to replace them.

Second, the industry is diversifying, with operators who performed their own fleet maintenance handing off more of that work to contract repair stations, where non-certificated mechanics make up a greater percentage of the workforce. There is, I think, a legitimate concern that aviation safety will be put at risk, especially if the ratio of uncertificated to certificated mechanics gets too high, leaving proportionally fewer FAA-certificated technicians to inspect and approve the work.

What is the ratio of non-certificated to licensed technicians? Is it 1 to 1, or 5 to 1, or even 20 to 1? We don't know what that ratio is today, which certainly suggests it isn't known tomorrow, at the same time the mechanics are being marginalized in the shift to what may be a mostly non-certificated workforce.

"We've been pushing for greater visibility of the FAA-certified license holders for 20 years," said Oliver "O.V." Delle-Femine, an official with the Aviation Mechanics Fraternal Association, about 85 percent of whose members are FAA-licensed. "People without the license lose pay because they cannot get a license premium."

Not only is the FAA-certification a source of pride, Delle-Femine said, "It shows how important our job is."

Amen.