Boston — The Federal Aviation Administration is planning in March to allow an increase in the number of commercial airplanes flying the nation's airways despite repeated warnings from the National Transportation Safety Board (NTSB), air controllers, and pilots. Under intense pressure from airlines, Congress, and the public to further reduce flight delays, the FAA is planning to boost the capacity of its air traffic control system by eliminating most air traffic ``in-trail restrictions'' nationwide by March 25.
In-trail separation restrictions limit the number of aircraft flying into busy airspace by designating how many miles apart airplanes must be. They were imposed to help keep the system from being swamped after President Reagan fired 11,500 striking controllers in 1981.
The effect, observers say, will be to increase the number of aircraft that controllers must handle during ``rush'' periods. Airborne holding patterns are also expected to become more common, since airport capacity remains static, although FAA officials deny that airborne holding will increase.
``These [in-trail] restrictions are the only thing keeping us alive during certain hours of the day,'' says Michael Ford, a veteran air traffic controller at Indianapolis Center, one of the FAA's 20 en route centers nationwide which control aircraft between airports.
In-trail restrictions frequently range from 10 to 20 miles, depending on weather conditions and aircraft volume. Five miles of horizontal separation and three miles in terminal areas are minimum standards. The in-trail restrictions mandate extra spacing on top of the minimums for certain routes in order to limit the number of airplanes controllers must handle during peak times. It allows flexibility to add merging aircraft into long lines of commercial jets, and is a crucial buffer if bad weather crops up.
The problem, say controllers and safety experts, is that the FAA is prematurely trying to push its air traffic capacity higher to get more planes in the air, even though its controller-staffing quotas in parts of the country remain unfilled.
Before the 1981 strike, there were 13,205 full-performance-level (FPL) air traffic controllers, according to the General Accounting Office, the independent investigative arm of Congress. Today, there are 8,944 FPL controllers, according to the FAA. Meanwhile, air traffic has increased 20 percent nationwide.
``The FAA doesn't have standards yet that are sufficiently refined to tell how many controllers they need or where they need them,'' says Kenneth Mead, an associate director of the GAO. ``Until those standards are done, it's difficult to say how much they could handle.''
In May, the NTSB warned in a safety recommendation that the FAA should ``permit no further relaxation in flow control measures including the en route miles in-trail separation restrictions.''
In a Dec. 16, letter from Safety Board chairman James Burnett, the Safety Board criticized the FAA because it did ``not provide a positive response'' to the May recommendation to safeguard in-trail restrictions.
FAA officials, on the other hand, contend that the system is not running at capacity and can handle more aircraft. Its program to reduce in-trail restrictions began in earnest last February.
``The feeling is that we may not be utilizing the total system to its greatest efficiency,'' says John R. Ryan, FAA director of air traffic operations. ``I'm not interested in making controllers work harder or work more airplanes. What I'm interested in doing is getting rid of ... unnecessary restrictions.''
As the debate goes on, however, an internal FAA document obtained by the Monitor shows that the FAA is planning ``automatic cancellation of all intrail restrictions of ten miles or greater on March 25, 1988, unless specifically justified'' by senior FAA air traffic managers in Washington.
The document is an informational bulletin written by a regional air traffic manager to traffic managers in his air traffic control center. He describes the cancellation of in-trail restrictions as the main topic of a five-day national meeting for air traffic managers last November. Other FAA traffic managers confirmed the move to automatically cancel in-trail restrictions in March.
``You have to realize the FAA is under extreme external pressure to put as many aircraft into the system as possible,'' says NTSB investigator David Kelley.
Others, including air traffic controllers and pilots, say an automatic nationwide cancellation of restrictions is not a good idea, since careful review of computer tape history of each specific restriction is needed before being deleted. The FAA's Mr. Ryan says reviews are being done at a regional level, though the NTSB complains in its December letter to the FAA that ``the FAA has not indicated that they have a formal program to follow up the effect of such changes on control workload or performance.''
``If the FAA has some magic device or technique nobody knows about, that might be interesting to discover,'' says John Galipault, president of the Aviation Safety Institute. ``Right now unless we see something that's not ethereal, I get very concerned about breaking the 10-mile limit.''
In June, the FAA reported that 125 of the nation's 652 sectors had ``potential capacity problems.'' Since then, the FAA has restructured airspace in the Eastern US and is training 1,649 new controllers. Bringing new controllers on board does little to relieve immediate pressure, since training takes three to five years.
Testifying before Congress last January, Air Line Pilots Association president Henry Duffy repeated ALPA's opposition to an airline industry recommendation to reduce in-trail restrictions.
The association's safety director, John O'Brien, says his organization has adapt-ed its position slightly to support limited reduction of in-trail restrictions in portions or the Southwest and central US where controller staffing quotas are full. ALPA would not support wholesale reductions in regions where quotas were not full, he says.
``The first way you notice a problem is listening to the [controller's] voice on the radio,'' Mr. O'Brien says. ``If that voice seemed a little excited, or pushed ... that's the first indicator to us we have a workload problem down there.''
FAA officials say in-trail restrictions for some heavily burdened airspaces would be retained after March 25. The FAA's Ryan says the move will absolutely not increase airborne holding.
Nevertheless, restrictions will be canceled ``unless you tell me you need this and somebody needs to look at it,'' Mr. Ryan says. ``Nobody in Washington or a regional office can say you've got to cancel everything and that's it, period. But my experience tells me maybe there's places that we can do better.''
Some controllers, however, say the system is so intertwined that canceling some restrictions and keeping others would make air traffic congestion worse during daily rush periods and result in more airborne holding.
``At 10:30 in the morning, we have a continuous line of TWA jets 15 miles apart, extending from Bible Grove, Ill., to western Pennsylvania,'' Mr. Ford says. ``What would happen if we let all those aircraft ride until they reached Indianapolis and left the final sorting to the guy in Indianapolis? It would be an impossibility. It's tough to do it now, and it takes three states to do it.''
As concern about air traffic density was peaking last spring before the summer travel season, the FAA unveiled a new computer system to aid its ``flow control'' system. The computer system updates the movement of aircraft nationwide every five minutes.
But the computer system cannot predict congestion points, although it was supposed to have that capability last September. FAA officials predict it will have such capability by June.
The NTSB is concerned that the much-publicized flow control, even with current in-trail restrictions and a new computer system, is still allowing potentially unsafe buildups of aircraft.
``We continue to investigate incidents that occur, because traffic has been allowed to increase to saturation levels,'' a federal air safety expert says. ``At certain airports and certain sectors [blocks of airspace] the FAA is running the system right up to the redline [limit] during peak travel hours. What that says to me is that the FAA should not be anxious to put any more flights into the system.''
Operational errors (where controllers allow aircraft to come closer together than FAA regulations permit) and near-collision statistics are two measures of the strain on the system.
Near-collisions have increased steadily every year, from 395 in fiscal 1981 to 1,007 in fiscal 1987. Last year's total was 20 percent higher than in fiscal 1986. Operational errors, which soared in the first part of last year, tapered off. From January through November last year, there were 1,139 errors, compared with 1,120 the year before.
In a report last May, the GAO said the FAA had been able to handle its load by shuffling work schedules and mandating overtime. This way, it has been able to have enough controllers to cope with rush periods, but still has not relieved the burden on controllers.
Would it be OK to add more aircraft to the system, even though bigger and longer rush periods could mean more controller overtime?
``They still don't have as many controllers as they need, and in the meantime the traffic keeps increasing, unless they put some sort of a cap on the capacity of the system,'' says Edward Wood, director of the Flight Safety Foundation. ``We recommended a cap after the strike. We recommended they only increase the capacity back into the system as they increase the FPL staffing. They chose not to do that, so they have a problem.''
Air traffic controller Fred Gilbert works in the Chicago Center, just outside Chicago's O'Hare International Airport. Chicago Center is one of the FAA's 20 en route centers and one of the most high-pressure air traffic regions in the country.
Staffing shortages, excessive overtime work, computer failures, radio failures, and other problems hamper Mr. Gilbert and other controllers, he says. Chicago Center is supposed to have 394 full-performance-level controllers. But in 1986, for example, Chicago Center's 185 controllers logged more than 46,000 hours of overtime, according to the GAO.
Despite the burden, Gilbert says, controllers have managed the growing air traffic burden safely, even though current in-trail spacing restrictions are ``the only thing that's saving us as far as all the pressure we're under.''