NAVIGATING THE BUSY SKIES: Air traffic controllers can provide invaluable guidance as aviators fly through weather and traffic, but pilots need to recognize their own responsibility with regards to continuing a flight. (Photo by John Ruley)
Each year, the National Air Traffic Controllers Association (NATCA), the union representing FAA controllers, honors members who’ve helped save pilots from dangerous situations that might have resulted in accidents. These members are given the Archie League Medal of Safety, an award named for the man credited as the first controller. In case you never heard of Archie William League, he was a barnstormer who flew mostly in Missouri and Illinois. In 1929, the City of St. Louis hired him to direct traffic at the airfield that eventually became Lambert-St. Louis International Airport. At first, he directed pilots by waving flags: red to hold or stop, and checkered to take off or otherwise go. In 1937, he was hired as a controller by the U.S. Bureau of Air Commerce, which later became the Civil Aeronautics Authority and, eventually, the FAA. In May 1965, he went to work in Washington, D.C., as the director of air traffic services, and subsequently became an FAA assistant administrator. He died in 1986.
This year, NATCA honored 16 controllers for their involvement in 11 flight assists in 2008. One controller helped a pilot with an onboard fire return to the departure airport; another enabled the pilot of a single-engine airplane to find a place to land after the engine failed during a night flight.
It’s nice to honor those who’ve successfully helped others, especially when we can learn from their experiences. A controller can be thought of as an additional crewmember, for purposes of applying crew resource management techniques, especially when the workload increases on a single-pilot flight. No matter how helpful a controller may try to be, however, it’s the pilot who’s ultimately responsible for exercising the proper judgment, having the necessary skills and maintaining command of the flight. Part of that pilot-in-command responsibility includes understanding the source and completeness of the information the controller is using to formulate the advice and instructions he or she is providing.
On December 22, 2006, a Cessna 421 Golden Eagle was en route from Destin, Fla., to Marsh Harbor in the Bahamas. Shortly after 8 a.m., the pilot contacted Eglin Clearance Delivery to “talk to somebody about the weather.” For about 15 minutes, the pilot and controller discussed the location of weather systems. There were several SIGMETs and AIRMETs that applied to the flight. The AIRMETs warned about IFR conditions and turbulence, including ceilings below 1,000 feet and visibilities below three miles in rain, fog and mist. Moderate turbulence was predicted below 12,000 feet. SIGMETs warned of thunderstorms with tops to 40,000 feet.
At about 8:30 a.m., the flight was cleared for takeoff with a right turn to a heading of 90 degrees and a climb to 2,000 feet. At 8:32:48 a.m., the pilot reported to Eglin South Approach Control that he was airborne and climbing to 2,000 feet. The pilot was then cleared to climb to 5,000 feet. Less than a minute later, the Eglin controller radioed, “In about another three miles, I’m showing…no weather at all between you and Pensacola [Florida].” For the next seven minutes, the Eglin controller gave the pilot vectors to get around traffic and “some weather that’s going to be southeast of your position” while the 421B finished the climb to 5,000 feet. At 8:35:18 a.m., the controller radioed the pilot, “There’s so much weather around, I don’t have a lot of area to vector you in.” Five minutes later, the controller instructed the pilot to contact Tyndall Approach, and the pilot acknowledged.
At 8:41:30 a.m., the pilot made contact with Tyndall Approach Control, and the controller advised, “I’m showing you just entering a line of weather that’s going to continue for the next 15 miles.” The pilot was instructed to maintain the last heading given by the previous controller, and then Tyndall Approach issued a broadcast for all aircraft on frequency that hazardous-weather AIRMETs were available on HIWAS, Flight Watch and Flight Service Station frequencies. At 8:44:52 a.m., the pilot contacted Tyndall Approach Control to ask if he still was on a “good” heading. The controller responded, “Fly heading one one zero,” and subsequently added, “I don’t have the weather radar that Eglin had. They put you up in this area based on the different levels of precipitation that they are showing. So all I show is precipitation returns. I’m showing you [at the] beginning line of a band of weather, and on that 110 heading, you’ll be breaking out of it in about 15 miles.” The pilot acknowledged, and then told the controller that he needed a block altitude clearance because he was “up and down here quite a bit.” The controller approved a block clearance for 4,000 feet through 6,000 feet. There were no further radio transmissions from the flight, which was lost from radar at 8:49 a.m.
A weather radar image taken from Eglin Air Force Base, which was recorded about 27 seconds before the airplane was lost from ATC radar, indicated that the airplane was close to at least one, and probably more, level-five (severe) thunderstorm. A meteorological study by the NTSB revealed that the airplane did penetrate an area of level-five weather radar echoes.
The airplane crashed into an area of heavy brush and trees at Greenhead, Fla. The ATP-rated pilot and all four passengers were killed. Records indicated that the pilot had about 15,000 hours of flight time, including approximately 900 hours in type. He had experience with a wide variety of aircraft, including military jets, and was a graduate of the U.S. Air Force Experimental Test Pilot School.
The NTSB determined that the probable cause of this accident was the pilot’s improper planning/decision and continued flight into known adverse weather, which resulted in an encounter with a level-five thunderstorm.
The pilot of a twin-engine Mitsubishi MU-2B-40 received a weather briefing on the morning of August 25, 2006, which indicated that there’d be widely scattered rain showers and thunderstorms along portions of the planned route of flight from Bloomington, Ind., to Eleuthera Island in the Bahamas. The flight was cruising at FL280 when the pilot made contact with Jacksonville Air Route Traffic Control Center (ARTCC) in Florida at about 12:22 p.m. When the pilot was switched to a different sector, he heard several aircraft requesting course deviations due to weather. The controller asked the Mitsubishi pilot if he needed to deviate from course before reaching the vicinity of Ormond Beach, Fla. The aircraft was equipped with weather radar, and the pilot said that he wouldn’t need any deviations.
At 12:52 p.m., the ARTCC controller announced that a convective SIGMET was in effect for South Carolina, Georgia, Florida and Florida coastal waters. The pilot advised the controller that he had reconsidered a deviation, but whether he’d change course depended on when the controller would allow him to proceed direct to his destination. The controller said that because of traffic, he needed the pilot to reach Ormond Beach before he could proceed direct to Eleuthera Island. The pilot then radioed that if he needed to deviate, he’d have to go 10 degrees to the right, but wouldn’t have to alter course for about 60 miles. When the pilot needed it up ahead, the controller approved the deviation, asking if the pilot would be able to make it back over Ormond Beach. The pilot replied that he wouldn’t, and it looked as if Ormond Beach was being affected by the weather at the moment. The controller commented that the airplane had better weather radar than he did and asked the pilot to advise when he could proceed direct to Melbourne, Fla. The pilot replied, “Ten [degrees] right now and direct Melbourne when able—I can handle that.”
At 1:06 p.m., the pilot radioed the ARTCC controller that he couldn’t maintain altitude. The controller tried to call the pilot, but there were no further radio transmissions from the airplane, which experienced an in-flight breakup and crashed near Bunnell, Fla. The commercial pilot and passenger were killed.
Investigators found the power switch for the airplane’s radar turned on. They also found that the radar antenna’s tilt control had been set at approximately four degrees up. A meteorological study found that very strong to intense thunderstorms existed around FL200, which was below the aircraft’s cruise altitude. With the antenna tilted up, the returns likely wouldn’t have appeared on the pilot’s display. Investigators noted, however, that they couldn’t determine whether the aircraft’s weather radar was depicting the stronger returns or if the pilot was aware of the stronger storms below his cruise altitude.
Controllers at the Jacksonville ARTCC had displays of NEXRAD weather radar returns. The weather displays had four settings: below FL240, between FL240 and FL330, above FL330, and from sea level to FL600. The display used by the controller handling the Mitsubishi was set to display weather returns between FL240 and FL330 because he was controlling traffic within that altitude band. The controller’s display showed only weak to moderate echoes above FL240.
The NTSB indicated that the accident’s probable cause was the pilot’s inadvertent encounter with thunderstorms.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other NTSB news. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.