Your article (March 30), "Aircraft Safety: Cracks Begin to Show in the System," reflects a current trend by news media around the country to examine more closely some of the technical areas involved in airline safety. As such, it represents a worthwhile endeavor.
Your accompanying editorial (March 30), "Warning Signals," based upon the story, correctly points out that "There is nothing inherently unsafe about older airplanes if they are scrupulously maintained." But neither the editorial nor the story take sufficient account of the commitment of the airlines to do just that.
The story argues that with many airplanes getting older, the airlines ought to be finding more structural cracks and spending more money doing it.
The argument is premised upon a theoretical aircraft lifetime fatigue model. In fact, the lifetime of an aircraft is safely extended by airlines through structural and other changes that lengthen the actual life span far beyond the original theoretical limit. There are hundreds of DC-3s still in service around the world and Douglas stopped making them 40 years ago.
In addition to design and other changes, the airlines systematically inspect aircraft for structural cracks and make repairs when necessary. The repairs can involve anything from simple patches to "reskinning" of entire aircraft surfaces. A properly maintained older aircraft is just as safe as a new one (sometimes older is better), and the more than 40,000 mechanics employed directly by the airlines are dedicated to proper maintenance.
The story pointed out that the Service Difficulty Reporting system, under which airlines must submit reports to the Federal Aviation Administration within a 72-hour period, is not sufficiently timely. The airlines agree, and they have said so in formal submissions to the FAA. But the true early warning system is not the FAA 72-hour reports; it is the immediate reporting, by the airlines to the manufacturers, of any and all kinds of difficulties that are encountered.
While The Times story acknowledges the existence of this long-standing practice, it overemphasizes the delays of the FAA reporting system and underplays the real significance of the reports to manufacturers. It is the manufacturers, after all, who have the technical expertise and resources for developing a technical solution when one is needed to address problems experienced by the airlines.
An additional point: People have tried to tie airline deregulation to a theoretical lessening of safety, usually arguing that airlines are merely "coasting" on some theoretical, ever-slimmer "margin of safety."
Here are the facts: The safety record since deregulation is better than before, but that's only because the trend has always been toward improvement. Nobody can "coast" on safety. Either it happens day-in and day-out because people make it happen, or we have accidents and the safety record declines. The safety record has improved overall and that is why U.S. airlines carry more than a million passengers a day safely on 15,000 flights. Safety is not only morally right, it also is good business.
The airlines are justifiably proud of their safety record over the decades, due to the dedicated work of their own employees, the manufacturers, and the FAA. Safety is the single most important factor that guides the business practices of airline management each and every day.
WILLIAM W. HOOVER
Executive Vice President
Operations and Safety
Air Transport Assn.