Alarms sounded in the cockpits of a Continental Airlines Inc. plane carrying 100 people and a Gulfstream II business jet, warning the pilots that they were headed for a collision more than 24,000 feet over Maryland.
The Continental pilot, bound for Newark, New Jersey, pushed down the Boeing Co. 737-800 to avoid a crash, the National Transportation Safety Board said. A controller’s error had put the planes within 300 feet of colliding, violating rules that aircraft remain at least 1,000 feet apart, the NTSB said.
The Maryland incident on March 25 is among more than 200 reports collected in the three months after the U.S. stepped up scrutiny of close calls in the air. While the safety board said most cases involved “no actual hazard,” it homed in on five incidents investigators said were serious and may have gone undetected without a disclosure rule that took effect March 8.
The five events were “probably the biggest surprise” from the new monitoring, John DiLisi, the NTSB’s deputy director of aviation safety, said in an interview. “Aircraft got so close together that evasive action was required. This is the type of serious incident we should be immediately notified about.”
The close calls in March, April and May have triggered Federal Aviation Administration investigations, said spokeswoman Alison Duquette. The agency also formed a group with air-traffic controllers that met for the first time this month to examine possible changes in training or procedures, she said.
“We take these incidents seriously,” said Doug Church, spokesman for the National Air Traffic Controllers Association, a Washington-based union for the control-tower workers. The rate for the most egregious violations of FAA separation standards rose to 3.31 per million controller commands in the eight months through May 31, up from 2.44 in the full year ending Sept. 30, 2009, according to the agency.
No Common Theme
The FAA has found no common theme in the NTSB’s five incidents, Duquette said. Regulators are examining cockpit-alert reports with an industry-agency team that seeks safety improvements, Peggy Gilligan, the FAA’s safety chief, told reporters June 15.
The March 8 rule requires that the NTSB be notified when cockpit alarms sound and crew action is needed to avoid a “substantial risk of collision.” The NTSB, which is independent of the FAA, investigates accidents and makes non- binding recommendations.
The board proposed the rule in 2008, after concluding it may not have been hearing about all near-collisions. Airlines, small-plane operators and pilots objected at the time that filing reports would be burdensome or unnecessary.
In addition to the Continental incident above Worton, Maryland, the NTSB is investigating near collisions above Chicago; San Francisco; Burbank, California; and Anchorage, Alaska.
An Empresa Brasileira de Aeronautica SA E135 operated by AMR Corp.’s American Eagle came within 300 feet of a King Air 300 turboprop after takeoff April 21 from Chicago O’Hare International Airport, according to an NTSB report. A cockpit alarm instructed the Eagle crew to take evasive action after an error in the control tower, the report found.
Eight days later, a Bombardier Inc. CL-600-2B19 regional jet operated by SkyWest Inc. received an alert to take evasive action while turning at 1,500 feet to land at Burbank, an NTSB report said. A TV news helicopter was approaching head-on at 1,200 feet, according to the report.
Houston-based Continental is “cooperating fully” with the investigation, spokeswoman Christen David said. American Eagle shared internal reports with the board, said Andrea Huguely, spokeswoman for the Fort Worth, Texas-based carrier. SkyWest crews are trained in avoidance procedures and the incident “demonstrates that proficiency,” said Marissa Snow, a spokeswoman for the St. George, Utah-based airline.
The NTSB previously disclosed two probes triggered by the rule. In one case, a US Airways Group Inc. jet came within 100 feet of a cargo plane in Anchorage, Alaska on May 21. In the other, a UAL Corp. United Airlines Boeing Co. 777-222 came within 200 feet of a small aircraft after takeoff March 27 from San Francisco.
Pilots are alerted by an aircraft’s Traffic Collision and Avoidance System. The technology has been required by the government since 1993 after incidents such as a 1986 crash over Cerritos, California, that killed 82 people. The devices are made by Honeywell International Inc., Rockwell Collins Inc. and Aviation Communication & Surveillance Systems, a joint venture of L-3 Communications Holdings Inc. and Thales SA.
‘Climb, Climb Now’
The units use radio signals and the transponders of nearby aircraft to give pilots a cockpit display and a succession of warnings from a buzzer, a red light and aural commands to “descend, descend” or “climb, climb now.”
Not all alerts signal a real risk of a collision because the devices can’t read the intent of pilots, said Bill Voss, president of the non-profit Flight Safety Foundation in Alexandria, Virginia. A pilot executing a pre-arranged plan to climb quickly through the path of crossing traffic may trigger an alert, even though there is no danger, he said.
Airlines remain unhappy with the reporting requirement, said David Castelveter, a spokesman for the Air Transport Association, which represents Delta Air Lines Inc., AMR’s American Airlines and United Airlines. Carriers may spend as many as 15 hours gathering information on an alert, duplicating data the FAA collects in voluntary programs, he said.
“Why is the NTSB getting into the business of data collection?” Castelveter said. “It’s onerous and burdensome.”