Crowded. Frighteningly complicated. And getting more so.
Air traffic over the San Fernando Valley, fed by three airports within six miles of each other, is beginning to resemble the busy freeways below.
And with landings and takeoffs projected to jump about 15% over the next three to five years, congestion is likely to increase.
In an average 24-hour period, more than 2,000 jets, small planes and helicopters take off and land from Van Nuys, Burbank and Whiteman airports, each crowded by surrounding mountains into a V-shaped basin. Such conditions make the Valley's airspace one of the most complex swaths of sky in the region.
And while the air safety record is good, pilots, air traffic controllers and representatives of some airlines are planning to make it better.
"The Valley's airspace is extremely complicated," said Kevin Karpe, president of the air traffic controllers union at the Federal Aviation Administration's regional headquarters in Burbank. "It's possibly one of the most complicated in the nation."
Eight near midair collisions have occurred in Valley skies over the past 21 months, and five in-flight collisions since 1964, with none since 1981. Still, pilots, air controllers and flight instructors do not consider the situation to be dangerous. FAA officials say the number of near midair collisions for the Valley is comparable to other regions with similar volumes of air traffic.
The Valley's air safety system works because aircraft are strictly regulated and pilots are well versed in the rules of Valley air, federal officials said.
"Does the system work? Of course it works," said Robert Jackson, a flight instructor with 52 years of experience as an aviator.
But a number of changes have been proposed in the way airspace is regulated and the rules that guide how pilots proceed through a hodgepodge of jurisdictions. The objective is to make the airspace in the Valley and in the rest of the Los Angeles region safer and simpler.
Known as the Southern California Airspace Users Group, a group of pilots, air traffic controllers and others are trying to devise a system to simplify fixed routes to guide pilots from one region to another without having to turn, descend and climb around various restricted airspaces. The group is also trying to make air traffic jurisdictions safer and easier for pilots to understand.
The proposal is expected to be considered by the FAA sometime next year.
In a bid to better coordinate air traffic, the FAA is consolidating five Southern California regional air control facilities into one building in San Diego. The consolidation, to be completed next year, will help controllers resolve air traffic problems faster and easier because all controllers will be under one roof, according to the FAA.
Despite those potential improvements, veteran pilots say that several elements complicate Valley airspace so much that local practices are unlikely to be altered soon, if ever.
As an example, because of physical limitations imposed by the Valley's mountain ranges, about 75% of the commercial jets descending for landing at Burbank Airport fly about 2,000 feet above Van Nuys Airport.
Burbank's landing pattern forces Van Nuys airplanes performing takeoff and landing patterns to stay within 1,000 feet of the ground and helicopters to remain below 500 feet.
"If you had to pick a place to put an airport, Van Nuys would not be the place," said George Slade, assistant manager for programs at the Burbank TRACON, the FAA's Terminal Radar Control facility, which regulates airspace in a 30-mile radius around Burbank Airport.
But he and other aviators say the condition is not inherently dangerous as long as pilots understand the rules of flying in and out of the area.
"It's like playing a three-dimensional game of chess: You have all these pieces that you want to get to where they want to go," he said.
More pilots fly in and out of Van Nuys than anywhere else in the country, and that number is expected to increase.
The busiest general aviation airport in the nation, Van Nuys Airport is the site of 1,425 flight operations per day, with 1,450 takeoffs and landings per day predicted in 1995, airport officials said.
Burbank, a fast-growing commercial airport, has about 576 daily operations. Airport officials predict that figure will grow to 775 by 1998 and about 900 by 2010.
Whiteman Airport, a county-owned airfield, has 317 daily operations, and is projected to have 508 operations by 1998 and 815 operations by 2003, airport officials estimate.
Putting that blizzard of aircraft in some order is the responsibility of air traffic controllers at regional levels, within the Los Angeles Basin, and at airport control towers.
In Palmdale, controllers watch airspace throughout most of the state south of San Francisco, "handing off" airliners as they descend to Los Angeles or taking handoffs as the jets gain altitude after takeoff.
At the other end of the handoff is a TRACON, short for Terminal Radar Approach Control. There are four TRACONs in the basin: L.A., Coast, Ontario and Burbank, each watching an airspace from the ground to 13,000 feet. Controllers in airport towers direct flights within five miles of the runway.
The regulated airspace for each control facility forms concentric circles on navigational charts. To draw the boundaries in three dimensions would be to form cylindrical shapes, like an upside-down wedding cake atop the airport runways.
To cross the boundaries, a pilot must contact the tower and ask permission to enter.
To the south of the Valley, airspace for Burbank, Van Nuys and Los Angeles International Airport boundaries meet just above the Santa Monica Mountains, forming a corridor in the sky over the Hollywood Hills, known to some pilots as "Kamikaze Alley."
It has been so dubbed because small aircraft pilots south of the hills trying to avoid the LAX airspace must fly below 5,000 feet. But as soon as they cross into Burbank airspace, they must be above 4,800 feet. As a result, many small planes cluster at the same altitude--about 4,900 feet--with a clearance of only 100 feet from jets overhead and below.
A near midair collision occurred on the night of Dec. 18, 1992, near the border of the LAX and Burbank airspaces, according to an incident report submitted to the FAA by one of the pilots.
The pilot of a helicopter departing Santa Monica Airport heading north said he saw a very bright blinking light below him that turned out to be a twin engine Cessna descending into Santa Monica, according to the report. The two aircraft came within about 300 feet, according to the report. The FAA evaluation of the incident described it as a "potentially" hazardous situation.
Congestion and pilot error are, according to air traffic controllers and pilots, the most common causes of near midair collisions, a term that under FAA procedures represents any incident reported by a pilot as being dangerous.
In 1992, there were three near midair collisions in a 10-mile radius of Van Nuys and Burbank airports. So far in 1993, there have been five near midair collisions. But controllers and pilots say the increased number of incidents does not signify a trend, as weather and other factors can increase and decrease the number of incidents from year to year.
An FAA spokesman said the same number of near midair collisions were reported during the same period at two airports with comparable proximity and air traffic levels, John Wayne Airport in Orange County and Long Beach Airport.
Generally, pilots and air traffic controllers say near midair collisions can be avoided if pilots know the boundaries of their airspace and where they are supposed to be.
"It all works out as long as everybody stays in his own airspace," said Slade of the Burbank TRACON.
The Freeways Above Us
The Valley's two major airports, only six miles apart, support a high volume of traffic, making airspace particularly complex and crowded. The mountainous rim requires most jets landing at Burbank Airport to descend directly over Van Nuys Airport, forcing Van Nuys air traffic to stay low.
Van Nuys Airport: The busiest general aviation airport in the nation, with 1,450 flight operations per day
Burbank Airport: A fast-growing commercial airport, with 576 flight operations per day
Commercial jets landing at Burbank approach at 2,000 feet, over Van Nuys
Fixed wing aircraft are limited to heights of 1,200 feet on takeoff or landing
Helicopter "ceiling" is 500 feet
Flight Zones: Each Valley airport has designated airspace that is regulated by air traffic controllers at those airports. The space is a different size and shape for each airport. Pilots must often climb, descend or turn to stay out of designated airspace and avoid having to contact local traffic controllers.
Close Calls: Reports of near midair collisions are filed by pilots to the FAA and represent an incident that the pilot feels is hazardous. Near midair collisions usually occur when a pilot wanders into the route or airspace of another aircraft.
Source: Federal Aviation Administration
1993 Location Proximity Jan. 2 1 mile NW of Burbank unknown Mar. 16 13 miles NE of LAX 700 ft. Mar. 30 8 miles N of Van Nuys 150 ft. May 1 4 miles SW of Burbank 2,700 ft. July 20 2 miles E of Van Nuys 1,430 ft. 1992 April 2 5 miles S of Van Nuys unknown Oct. 10 13 miles SW of Van Nuys 3,040 Nov. 15 10 miles NE of Santa Monica 316 ft.
Sources: Federal Aviation Administration