THE FLIGHT OF 51 DELTA

To show how the Federal Aviation Administration’s air traffic control system works, a single engine plane, Cessna N9351D--known in FAA parlance simply as “51 Delta”--flew from Gorman to Los Angeles Airport. Here is an account of that hourlong flight:

Flight 51 Delta entered the 180,000-square-mile area controlled at Palmdale and descended to 9,000 feet as passed over Lake Hughes. 51 Delta’s pilot contacted controllers at Los Angeles Air Route Traffic Control Center.

51 Delta: “Los Angeles Center, Cessna 9-er 351 Delta’s at Lake Hughes.”

Palmdale: “9-er 351 Delta. Los Angeles Center. Go Ahead.”

51 Delta: “51 Delta’s turning onto Victor 459 now.”(1)

Palmdale: “51 Delta, roger.”

Victor 459 is an air route leading into the Los Angeles Basin, part of a nationwide network of highways in the sky. When Palmdale saw that 51 Delta was moving into the airpace controlled by the traffic control center at Burbank Airport--known as Burbank TRACON, or “Burbank Approach”--it advised the plane to switch to the radio frequency used by the Burbank controllers.

Switching frequencies, 51 Delta’s pilot got on the radio again.

51 Delta: “Burbank Approach. Cessna 9-er 351 Delta level at 9,000.”

Burbank: “Cessna 9-er 351 Delta, Burbank Approach. Altimeter 30.12 . . . Maintain 9,000.”

The pilot adjusted his altimeter to 30.12 inches of mercury , so that the instrument would provide accurate altitude readings that day. The plane continued on Victor 459--crossing the Antelope Valley Freeway near Canyon Country and passing over Mendenhall Peak, above Sunland, he responded to Burbank’s advisories to drop to 8,000 feet, (3), then to 7,000 (4) and then to 6,000. (5) Minutes later, as the Cessna passed over downtown Glendale, Burbank TRACON advised the plane to descend to 4,000 and handed it over to Los Angeles TRACON, the control facility that lines planes up in sequence for their final approaches to Los Angeles International Airport:

51 Delta: “Los Angeles Approach, Cessna 9-er 351 Delta out of 6,000 for 4.” (6)

L.A. TRACON: “Cessna 9-er 351 Delta, Los Angeles Approach. Thank you . . . Maintain 4,000 . . . Clear, visibility 4 miles, haze. Temperature 71, dewpoint 62. Wind 240 (degrees) at 11 (knots). Altimeter 30.12 . . . Expect a visual approach to Runway 25 right. Caution, wake turbulence. You’ll follow a Boeing 737 straight in from the east that’s landing on 25 Left.”

Two minutes later, L.A. TRACON advised 51 Delta to “descend and maintain 2,500” and waited for a response:

51 Delta: “51 Delta out of 4 for 2,500.”

L.A. TRACON: “Cessna 51 Delta, turn right, heading 260 (degrees). “I’ll point out the Boeing 737 you’ll follow as he goes by on your left.” (7)

51 Delta: “Right, heading 260. 51 Delta.”

Turning west about a mile and a half southeast of the Los Angeles Civic Center, 51 Delta roughly paralleled the Santa Monica Freeway for about a minute before receiving further instructions:

L.A. TRACON: “Cessna 51 Delta. Traffic at your 8 to 9 o’clock and 4 miles is the Boeing 737 that’s proceeding to the airport, landing on 25 Left. Turn left heading l80 (degrees). Report him in sight.”(8)

The little plane turned south and reported a “contact on the traffic” -- the pilot had seen the big Boeing.

L.A. TRACON: “Cessna 51 Delta,. . .fly heading 180 and I’ll turn your final (approach) right over the (Harbor) freeway.”

51 DELTA: “51 Delta. Roger . . . .”

L.A. TRACON: “Cessna 51 Delta. You may start your right turn now towards the airport. You’re cleared for visual approach to Runway 25 Right. Contact Los Angeles Tower on 120.95. . . . Good day, sir.”(9)

Turning west as directed, 51 Delta began its final descent under the eye of the control “cab” atop the 150-foot tower at LAX. Five miles from the east end of the runway, 51 Delta switched to radio frequency 120.95 and called the local controller handling the south runways:

51 Delta: “Los Angeles Tower, Cessna 9-er 351 Delta. Approach to 25 Right.”

LAX Tower: “Cessna 51 Delta, Los Angeles Tower. Runway 25 right. Cleared to land.” (10)

About three minutes later, Flight 51 Delta , one of thousands of planes FAA personnel guided through the crowded skies over Southern California, touched down safely. 51 Delta had landed.