After investigating more than 140,000 aviation accidents, the National Transportation Safety Board has fact-based authority for its recommendations on how to make the skies safer. Unfortunately, the Federal Aviation Administration doesn't always pay heed. Case in point: Even though nine people died in glider-aircraft collisions over the past 20 years, FAA has still not followed NTSB's 2008 recommendation to require gliders to carry transponders so that air traffic controllers and other pilots can "see" them in the sky. Nor has FAA followed through on other recommendations that would establish a national transponder code specifically for gliders, ensure that air traffic controllers know the new code, and develop guidelines for "the prompt installation and approval of transponders" on gliders.

Apparently, the FAA just doesn't do prompt. NTSB's oldest "open" recommendation, made 17 years ago when Bill Clinton was president, urged FAA to require that pilots get ongoing training to take immediate evasive action whenever warned by the Traffic Collision and Alerting System in the cockpit. TCAS sounds a warning whenever it thinks another aircraft has gotten too close.

NTSB "believes it is crucial for flight crews to be able to quickly evaluate, interpret, and execute" TCAS commands, and that because response time is literally a matter of seconds, training should be ongoing and not limited to pilots' initial orientation. But FAA has still not formally implemented this commonsense recommendation.

Like transponders, TCAS is designed to keep planes a safe distance apart. A close call last March in San Francisco illustrates why ongoing pilot training is necessary. The crew of a United Boeing 777 headed to Beijing with 181 people aboard reported seeing the underside of a small private plane that had been cleared by air traffic controllers just seconds after hearing their TCAS alarm go off. The planes came within 300 feet of colliding.

The good news is that of 787 TCAS activations reported to NTSB between March 2010 and January 2011, when NTSB started collecting its own cockpit collision-avoidance data, only a "handful" are considered worrisome, a board spokesman told The Washington Examiner.

The bad news? "The fact that separation of aircraft had to be maintained by the flight crews in response to an anti-collision warning rather than by air traffic control may warrant further inquiry," the spokesman said.

TCAS' importance in preventing mid-air collisions was heightened on Dec. 21, when Department of Transportation Inspector General Calvin Scovel issued a report to Congress noting a "cascading effect" of serious flaws -- including software glitches -- in NextGen, the FAA's new $2.1 billion air traffic control system.

Scovel pointed out that numerous gaps remain between another federal aviation advisory committee's recommendations and FAA's actions to date.

Late last month, FAA published a proposed Airworthiness Directive in the Federal Register that would require flight operators to upgrade TCAS units that failed in tests over high-density airports because it "could compromise separation of air traffic and lead to subsequent mid-air collisions."

If FAA acknowledges the importance of on-board collision avoidance technology, why has it not implemented NTSB's recommendations on glider transponders and TCAS training, which both have the same goal?

An FAA spokeswoman told The Examiner that the TCAS issue is part of a "major rewrite" of training rules for pilots and dispatchers, but did not explain why this process has taken 17 years. By coincidence, FAA is now operating on its 17th extension since its last reauthorization bill expired in 2007.

NTSB is a purely investigative agency with no power to force FAA to follow any of its recommendations, but members of Congress have a lot of leverage over the aviation agency. The question is, will they use it before another tragedy happens.

Barbara F. Hollingsworth is The Examiner's local opinion editor.