Van Nuys Airport Installs 24-Hour Weather Center

Coming in to Van Nuys Airport on a November night, cargo plane pilot Robert A. Olson was all alone. With no one on the ground to warn him of weather on the runway, he crashed to his death in a fog bank that for four hours concealed the wreckage where his body lay.

Although it’s uncertain if it would have saved Olson’s life, a new system soon to be activated at the airport is supposed to make sure that pilots are never alone again, even after the control tower closes at night. An automated station, “speaking” through a computerized voice, will report key weather conditions, updated by the minute.

“Pilots will have access to real-time weather information 24 hours a day even if there is no human being making observations,” said Mitch Barker, spokesman for the Federal Aviation Administration.

While the system has critics who contend that it cannot replace the immediacy or accuracy of human response, many concede that it could help overall efforts to provide weather updates.

The new system, establishing a network of automated weather stations at airports across the nation, will not only help pilots at locations such as Van Nuys, where the FAA’s air traffic controllers are not on duty around the clock.

It will also improve safety at major commercial airports “because it allows us to have more weather observations used by our people in telling pilots what they can expect,” Barker said.

Until recently, accurately predicting weather conditions was like “fishing for minnows with a chain-link fence,” as one research meteorologist put it. Observation sites and equipment were just too sparse to accurately paint a picture, leaving a weather system that many say has been marginal at best for 30 years.

But all that is changing with a massive modernization and restructuring of weather reporting techniques, led by the National Oceanic and Atmospheric Administration.

One phase of the modernization, now completed, was installation of the Doppler radar system--responsible for supplying information for the familiar multicolored weather maps appearing on TV screens and in newspapers.

Another is the Automated Surface Observing System, or ASOS, the system being installed at Van Nuys and hundreds of other airports across the country. Computer-based weather stations, consisting of eight unobtrusive-looking sensing devices erected in a row, are replacing and supplanting human observation stations.

While human weather observers at airports across the nation routinely update reports every hour, the automatic systems work by the minute, 24 hours a day.

Since the program began in 1992, 952 automatic systems have been installed nationwide, more than double the number of manned sites.

But well more than half of those still are not in operation because of continuing tests and changes to improve accuracy and reliability, said Susan Callis, ASOS acquisition manager for the National Weather Service, which oversees the program.

The Van Nuys Airport system was installed last August, on a grassy patch north of the control tower on the west side of the airport, between the main runway and a taxiway. The system, however, is still undergoing quality and reliability tests and is not expected to be in general use until October at the earliest, federal officials said.

The automated systems, which cost about $170,000 each, provide information on a variety of atmospheric conditions, such as cloud height, visibility, rain, temperature, wind direction and speed. Detailed information is offered on an Internet site, at https://www.nws.noaa.gov. A challenge in navigating the site is interpreting bureaucratic acronyms and such terms as “Liquid Precipitation Accumulation Sensor”--a rain gauge.

The FAA, while enthusiastic about the automated systems, has asked for a series of improvements. The instruments, for instance, tend to report visibility under certain conditions as greater than what is perceived by the human eye. A sensor that measures wind speed can freeze and a device that reports the dew point corrodes.

The problems are blamed for the lengthy delays in activating systems.

At Van Nuys Airport, no one is on duty to provide local weather reports when the tower is closed daily between 11 p.m. and 6 a.m. Pilots must rely on reports from Burbank Airport, which is manned around the clock, and from radar controllers in San Diego, who relay information from pilots flying out of Van Nuys.

“Burbank’s weather is not Van Nuys’ weather,” said Robert Jackson of North Hollywood, a private pilot and chairman of the Van Nuys Airport Citizens Advisory Council. “When the tower is closed, we have no real-time local weather reporting.”

Jackson and others say the system might have saved the life of the ill-fated pilot last November. “It’s too bad it wasn’t activated then,” he said.

“It possibly could have helped him,” said Todd Morris, head meteorologist with the National Weather Service in Oxnard. “If the tower is not open, a pilot who wants to fly in late at night has no idea what weather is occurring.”

“Now, when Van Nuys Airport closes at night, all we’re doing is just guessing.”

Others, however, say the new system probably would not have made a difference in that instance.

Olson, a seasoned pilot, was carrying a load of canceled bank checks from Las Vegas to Burbank when he was detoured because of fog conditions at Burbank.

An FAA controller told Olson that other pilots indicated conditions were still clear at Van Nuys, and Olson reported as he approached at 1:17 a.m. that he could see the airport.

Two minutes later, an airport security officer said visibility dropped to zero. No one heard the crash and there was no fire. Olson’s body was not discovered until almost dawn.

“That fog was rolling in at the same time the airplane was trying to land. There’s not a system in existence that could have prevented” the accident, said David Chaillot, a radar technician at Burbank Airport.

“I don’t know that ASOS would have done any good or not. It was just the worst timing in the worst way.”

The uncertainty centers on the inability of the automated system to immediately report sudden changes, such as a fast-moving fog bank. Unlike a human observer, who could immediately make a special report to pilots on rapidly changing conditions, the computerized system, which calibrates in logarithms, would take about nine minutes to issue a warning--probably too much time to have helped Olson.

“I hate to play the devil’s advocate, but from a forecaster’s standpoint, we’re missing an important element--the human element,” said Mike Wittman, Los Angeles meteorologist-manager for Universal Weather and Aviation, a private worldwide weather reporting service.

“We’re missing the human observer who can look out on the entire horizon around the airport and see the thunderstorm on the other side of the field,” Wittman said. “The ceiling measuring device can only look straight up.”

Even though Wittman and others say they prefer human observers, they concede that the automated systems fill important gaps, such as at Van Nuys. “There are airports out there that are sending weather information that was not sent before,” Wittman said.

The automated system “wasn’t designed to be the end-all for weather information,” said Marilu A. Trainor, public affairs specialist for the weather service’s western regional office in Salt Lake City. “Some pilot organizations have real problems or concerns because of the way the observations are taken. But ASOS is a very important tool.”